Testing from the XFS folk revealed that there is still too much I/O from the end of the LRU in kswapd. Previously it was considered acceptable by VM people for a small number of pages to be written back from reclaim with testing generally showing about 0.3% of pages reclaimed were written back (higher if memory was low). That writing back a small number of pages is ok has been heavily disputed for quite some time and Dave Chinner explained it well; It doesn't have to be a very high number to be a problem. IO is orders of magnitude slower than the CPU time it takes to flush a page, so the cost of making a bad flush decision is very high. And single page writeback from the LRU is almost always a bad flush decision. To complicate matters, filesystems respond very differently to requests from reclaim according to Christoph Hellwig; xfs tries to write it back if the requester is kswapd ext4 ignores the request if it's a delayed allocation btrfs ignores the request As a result, each filesystem has different performance characteristics when under memory pressure and there are many pages being dirtied. In some cases, the request is ignored entirely so the VM cannot depend on the IO being dispatched. The objective of this series is to reduce writing of filesystem-backed pages from reclaim, play nicely with writeback that is already in progress and throttle reclaim appropriately when writeback pages are encountered. The assumption is that the flushers will always write pages faster than if reclaim issues the IO. A secondary goal is to avoid the problem whereby direct reclaim splices two potentially deep call stacks together. There is a potential new problem as reclaim has less control over how long before a page in a particularly zone or container is cleaned and direct reclaimers depend on kswapd or flusher threads to do the necessary work. However, as filesystems sometimes ignore direct reclaim requests already, it is not expected to be a serious issue. Patch 1 disables writeback of filesystem pages from direct reclaim entirely. Anonymous pages are still written. Patch 2 removes dead code in lumpy reclaim as it is no longer able to synchronously write pages. This hurts lumpy reclaim but there is an expectation that compaction is used for hugepage allocations these days and lumpy reclaim's days are numbered. Patches 3-4 add warnings to XFS and ext4 if called from direct reclaim. With patch 1, this "never happens" and is intended to catch regressions in this logic in the future. Patch 5 disables writeback of filesystem pages from kswapd unless the priority is raised to the point where kswapd is considered to be in trouble. Patch 6 throttles reclaimers if too many dirty pages are being encountered and the zones or backing devices are congested. Patch 7 invalidates dirty pages found at the end of the LRU so they are reclaimed quickly after being written back rather than waiting for a reclaimer to find them I consider this series to be orthogonal to the writeback work but it is worth noting that the writeback work affects the viability of patch 8 in particular. I tested this on ext4 and xfs using fs_mark, a simple writeback test based on dd and a micro benchmark that does a streaming write to a large mapping (exercises use-once LRU logic) followed by streaming writes to a mix of anonymous and file-backed mappings. The command line for fs_mark when botted with 512M looked something like ./fs_mark -d /tmp/fsmark-2676 -D 100 -N 150 -n 150 -L 25 -t 1 -S0 -s 10485760 The number of files was adjusted depending on the amount of available memory so that the files created was about 3xRAM. For multiple threads, the -d switch is specified multiple times. The test machine is x86-64 with an older generation of AMD processor with 4 cores. The underlying storage was 4 disks configured as RAID-0 as this was the best configuration of storage I had available. Swap is on a separate disk. Dirty ratio was tuned to 40% instead of the default of 20%. Testing was run with and without monitors to both verify that the patches were operating as expected and that any performance gain was real and not due to interference from monitors. Here is a summary of results based on testing XFS. 512M1P-xfs Files/s mean 32.69 ( 0.00%) 34.44 ( 5.08%) 512M1P-xfs Elapsed Time fsmark 51.41 48.29 512M1P-xfs Elapsed Time simple-wb 114.09 108.61 512M1P-xfs Elapsed Time mmap-strm 113.46 109.34 512M1P-xfs Kswapd efficiency fsmark 62% 63% 512M1P-xfs Kswapd efficiency simple-wb 56% 61% 512M1P-xfs Kswapd efficiency mmap-strm 44% 42% 512M-xfs Files/s mean 30.78 ( 0.00%) 35.94 (14.36%) 512M-xfs Elapsed Time fsmark 56.08 48.90 512M-xfs Elapsed Time simple-wb 112.22 98.13 512M-xfs Elapsed Time mmap-strm 219.15 196.67 512M-xfs Kswapd efficiency fsmark 54% 56% 512M-xfs Kswapd efficiency simple-wb 54% 55% 512M-xfs Kswapd efficiency mmap-strm 45% 44% 512M-4X-xfs Files/s mean 30.31 ( 0.00%) 33.33 ( 9.06%) 512M-4X-xfs Elapsed Time fsmark 63.26 55.88 512M-4X-xfs Elapsed Time simple-wb 100.90 90.25 512M-4X-xfs Elapsed Time mmap-strm 261.73 255.38 512M-4X-xfs Kswapd efficiency fsmark 49% 50% 512M-4X-xfs Kswapd efficiency simple-wb 54% 56% 512M-4X-xfs Kswapd efficiency mmap-strm 37% 36% 512M-16X-xfs Files/s mean 60.89 ( 0.00%) 65.22 ( 6.64%) 512M-16X-xfs Elapsed Time fsmark 67.47 58.25 512M-16X-xfs Elapsed Time simple-wb 103.22 90.89 512M-16X-xfs Elapsed Time mmap-strm 237.09 198.82 512M-16X-xfs Kswapd efficiency fsmark 45% 46% 512M-16X-xfs Kswapd efficiency simple-wb 53% 55% 512M-16X-xfs Kswapd efficiency mmap-strm 33% 33% Up until 512-4X, the FSmark improvements were statistically significant. For the 4X and 16X tests the results were within standard deviations but just barely. The time to completion for all tests is improved which is an important result. In general, kswapd efficiency is not affected by skipping dirty pages. 1024M1P-xfs Files/s mean 39.09 ( 0.00%) 41.15 ( 5.01%) 1024M1P-xfs Elapsed Time fsmark 84.14 80.41 1024M1P-xfs Elapsed Time simple-wb 210.77 184.78 1024M1P-xfs Elapsed Time mmap-strm 162.00 160.34 1024M1P-xfs Kswapd efficiency fsmark 69% 75% 1024M1P-xfs Kswapd efficiency simple-wb 71% 77% 1024M1P-xfs Kswapd efficiency mmap-strm 43% 44% 1024M-xfs Files/s mean 35.45 ( 0.00%) 37.00 ( 4.19%) 1024M-xfs Elapsed Time fsmark 94.59 91.00 1024M-xfs Elapsed Time simple-wb 229.84 195.08 1024M-xfs Elapsed Time mmap-strm 405.38 440.29 1024M-xfs Kswapd efficiency fsmark 79% 71% 1024M-xfs Kswapd efficiency simple-wb 74% 74% 1024M-xfs Kswapd efficiency mmap-strm 39% 42% 1024M-4X-xfs Files/s mean 32.63 ( 0.00%) 35.05 ( 6.90%) 1024M-4X-xfs Elapsed Time fsmark 103.33 97.74 1024M-4X-xfs Elapsed Time simple-wb 204.48 178.57 1024M-4X-xfs Elapsed Time mmap-strm 528.38 511.88 1024M-4X-xfs Kswapd efficiency fsmark 81% 70% 1024M-4X-xfs Kswapd efficiency simple-wb 73% 72% 1024M-4X-xfs Kswapd efficiency mmap-strm 39% 38% 1024M-16X-xfs Files/s mean 42.65 ( 0.00%) 42.97 ( 0.74%) 1024M-16X-xfs Elapsed Time fsmark 103.11 99.11 1024M-16X-xfs Elapsed Time simple-wb 200.83 178.24 1024M-16X-xfs Elapsed Time mmap-strm 397.35 459.82 1024M-16X-xfs Kswapd efficiency fsmark 84% 69% 1024M-16X-xfs Kswapd efficiency simple-wb 74% 73% 1024M-16X-xfs Kswapd efficiency mmap-strm 39% 40% All FSMark tests up to 16X had statistically significant improvements. For the most part, tests are completing faster with the exception of the streaming writes to a mixture of anonymous and file-backed mappings which were slower in two cases In the cases where the mmap-strm tests were slower, there was more swapping due to dirty pages being skipped. The number of additional pages swapped is almost identical to the fewer number of pages written from reclaim. In other words, roughly the same number of pages were reclaimed but swapping was slower. As the test is a bit unrealistic and stresses memory heavily, the small shift is acceptable. 4608M1P-xfs Files/s mean 29.75 ( 0.00%) 30.96 ( 3.91%) 4608M1P-xfs Elapsed Time fsmark 512.01 492.15 4608M1P-xfs Elapsed Time simple-wb 618.18 566.24 4608M1P-xfs Elapsed Time mmap-strm 488.05 465.07 4608M1P-xfs Kswapd efficiency fsmark 93% 86% 4608M1P-xfs Kswapd efficiency simple-wb 88% 84% 4608M1P-xfs Kswapd efficiency mmap-strm 46% 45% 4608M-xfs Files/s mean 27.60 ( 0.00%) 28.85 ( 4.33%) 4608M-xfs Elapsed Time fsmark 555.96 532.34 4608M-xfs Elapsed Time simple-wb 659.72 571.85 4608M-xfs Elapsed Time mmap-strm 1082.57 1146.38 4608M-xfs Kswapd efficiency fsmark 89% 91% 4608M-xfs Kswapd efficiency simple-wb 88% 82% 4608M-xfs Kswapd efficiency mmap-strm 48% 46% 4608M-4X-xfs Files/s mean 26.00 ( 0.00%) 27.47 ( 5.35%) 4608M-4X-xfs Elapsed Time fsmark 592.91 564.00 4608M-4X-xfs Elapsed Time simple-wb 616.65 575.07 4608M-4X-xfs Elapsed Time mmap-strm 1773.02 1631.53 4608M-4X-xfs Kswapd efficiency fsmark 90% 94% 4608M-4X-xfs Kswapd efficiency simple-wb 87% 82% 4608M-4X-xfs Kswapd efficiency mmap-strm 43% 43% 4608M-16X-xfs Files/s mean 26.07 ( 0.00%) 26.42 ( 1.32%) 4608M-16X-xfs Elapsed Time fsmark 602.69 585.78 4608M-16X-xfs Elapsed Time simple-wb 606.60 573.81 4608M-16X-xfs Elapsed Time mmap-strm 1549.75 1441.86 4608M-16X-xfs Kswapd efficiency fsmark 98% 98% 4608M-16X-xfs Kswapd efficiency simple-wb 88% 82% 4608M-16X-xfs Kswapd efficiency mmap-strm 44% 42% Unlike the other tests, the fsmark results are not statistically significant but the min and max times are both improved and for the most part, tests completed faster. There are other indications that this is an improvement as well. For example, in the vast majority of cases, there were fewer pages scanned by direct reclaim implying in many cases that stalls due to direct reclaim are reduced. KSwapd is scanning more due to skipping dirty pages which is unfortunate but the CPU usage is still acceptable In an earlier set of tests, I used blktrace and in almost all cases throughput throughout the entire test was higher. However, I ended up discarding those results as recording blktrace data was too heavy for my liking. On a laptop, I plugged in a USB stick and ran a similar tests of tests using it as backing storage. A desktop environment was running and for the entire duration of the tests, firefox and gnome terminal were launching and exiting to vaguely simulate a user. 1024M-xfs Files/s mean 0.41 ( 0.00%) 0.44 ( 6.82%) 1024M-xfs Elapsed Time fsmark 2053.52 1641.03 1024M-xfs Elapsed Time simple-wb 1229.53 768.05 1024M-xfs Elapsed Time mmap-strm 4126.44 4597.03 1024M-xfs Kswapd efficiency fsmark 84% 85% 1024M-xfs Kswapd efficiency simple-wb 92% 81% 1024M-xfs Kswapd efficiency mmap-strm 60% 51% 1024M-xfs Avg wait ms fsmark 5404.53 4473.87 1024M-xfs Avg wait ms simple-wb 2541.35 1453.54 1024M-xfs Avg wait ms mmap-strm 3400.25 3852.53 The mmap-strm results were hurt because firefox launching had a tendency to push the test out of memory. On the postive side, firefox launched marginally faster with the patches applied. Time to completion for many tests was faster but more importantly - the "Avg wait" time as measured by iostat was far lower implying the system would be more responsive. It was also the case that "Avg wait ms" on the root filesystem was lower. I tested it manually and while the system felt slightly more responsive while copying data to a USB stick, it was marginal enough that it could be my imagination. This patch: do not writeback filesystem pages in direct reclaim. When kswapd is failing to keep zones above the min watermark, a process will enter direct reclaim in the same manner kswapd does. If a dirty page is encountered during the scan, this page is written to backing storage using mapping->writepage. This causes two problems. First, it can result in very deep call stacks, particularly if the target storage or filesystem are complex. Some filesystems ignore write requests from direct reclaim as a result. The second is that a single-page flush is inefficient in terms of IO. While there is an expectation that the elevator will merge requests, this does not always happen. Quoting Christoph Hellwig; The elevator has a relatively small window it can operate on, and can never fix up a bad large scale writeback pattern. This patch prevents direct reclaim writing back filesystem pages by checking if current is kswapd. Anonymous pages are still written to swap as there is not the equivalent of a flusher thread for anonymous pages. If the dirty pages cannot be written back, they are placed back on the LRU lists. There is now a direct dependency on dirty page balancing to prevent too many pages in the system being dirtied which would prevent reclaim making forward progress. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1378 lines
33 KiB
C
1378 lines
33 KiB
C
/*
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* linux/mm/vmstat.c
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*
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* Manages VM statistics
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* zoned VM statistics
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* Copyright (C) 2006 Silicon Graphics, Inc.,
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* Christoph Lameter <christoph@lameter.com>
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*/
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include <linux/vmstat.h>
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#include <linux/sched.h>
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#include <linux/math64.h>
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#include <linux/writeback.h>
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#include <linux/compaction.h>
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#ifdef CONFIG_VM_EVENT_COUNTERS
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DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
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EXPORT_PER_CPU_SYMBOL(vm_event_states);
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static void sum_vm_events(unsigned long *ret)
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{
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int cpu;
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int i;
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memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
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for_each_online_cpu(cpu) {
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struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
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for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
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ret[i] += this->event[i];
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}
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}
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/*
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* Accumulate the vm event counters across all CPUs.
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* The result is unavoidably approximate - it can change
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* during and after execution of this function.
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*/
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void all_vm_events(unsigned long *ret)
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{
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get_online_cpus();
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sum_vm_events(ret);
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put_online_cpus();
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}
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EXPORT_SYMBOL_GPL(all_vm_events);
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#ifdef CONFIG_HOTPLUG
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/*
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* Fold the foreign cpu events into our own.
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*
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* This is adding to the events on one processor
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* but keeps the global counts constant.
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*/
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void vm_events_fold_cpu(int cpu)
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{
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struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
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int i;
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for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
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count_vm_events(i, fold_state->event[i]);
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fold_state->event[i] = 0;
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}
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}
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#endif /* CONFIG_HOTPLUG */
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#endif /* CONFIG_VM_EVENT_COUNTERS */
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/*
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* Manage combined zone based / global counters
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*
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* vm_stat contains the global counters
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*/
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atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
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EXPORT_SYMBOL(vm_stat);
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#ifdef CONFIG_SMP
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int calculate_pressure_threshold(struct zone *zone)
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{
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int threshold;
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int watermark_distance;
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/*
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* As vmstats are not up to date, there is drift between the estimated
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* and real values. For high thresholds and a high number of CPUs, it
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* is possible for the min watermark to be breached while the estimated
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* value looks fine. The pressure threshold is a reduced value such
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* that even the maximum amount of drift will not accidentally breach
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* the min watermark
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*/
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watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
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threshold = max(1, (int)(watermark_distance / num_online_cpus()));
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/*
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* Maximum threshold is 125
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*/
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threshold = min(125, threshold);
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return threshold;
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}
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int calculate_normal_threshold(struct zone *zone)
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{
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int threshold;
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int mem; /* memory in 128 MB units */
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/*
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* The threshold scales with the number of processors and the amount
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* of memory per zone. More memory means that we can defer updates for
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* longer, more processors could lead to more contention.
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* fls() is used to have a cheap way of logarithmic scaling.
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*
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* Some sample thresholds:
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*
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* Threshold Processors (fls) Zonesize fls(mem+1)
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* ------------------------------------------------------------------
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* 8 1 1 0.9-1 GB 4
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* 16 2 2 0.9-1 GB 4
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* 20 2 2 1-2 GB 5
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* 24 2 2 2-4 GB 6
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* 28 2 2 4-8 GB 7
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* 32 2 2 8-16 GB 8
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* 4 2 2 <128M 1
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* 30 4 3 2-4 GB 5
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* 48 4 3 8-16 GB 8
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* 32 8 4 1-2 GB 4
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* 32 8 4 0.9-1GB 4
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* 10 16 5 <128M 1
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* 40 16 5 900M 4
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* 70 64 7 2-4 GB 5
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* 84 64 7 4-8 GB 6
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* 108 512 9 4-8 GB 6
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* 125 1024 10 8-16 GB 8
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* 125 1024 10 16-32 GB 9
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*/
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mem = zone->present_pages >> (27 - PAGE_SHIFT);
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threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
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/*
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* Maximum threshold is 125
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*/
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threshold = min(125, threshold);
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return threshold;
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}
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/*
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* Refresh the thresholds for each zone.
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*/
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void refresh_zone_stat_thresholds(void)
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{
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struct zone *zone;
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int cpu;
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int threshold;
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for_each_populated_zone(zone) {
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unsigned long max_drift, tolerate_drift;
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threshold = calculate_normal_threshold(zone);
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for_each_online_cpu(cpu)
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per_cpu_ptr(zone->pageset, cpu)->stat_threshold
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= threshold;
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/*
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* Only set percpu_drift_mark if there is a danger that
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* NR_FREE_PAGES reports the low watermark is ok when in fact
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* the min watermark could be breached by an allocation
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*/
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tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
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max_drift = num_online_cpus() * threshold;
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if (max_drift > tolerate_drift)
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zone->percpu_drift_mark = high_wmark_pages(zone) +
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max_drift;
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}
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}
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void set_pgdat_percpu_threshold(pg_data_t *pgdat,
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int (*calculate_pressure)(struct zone *))
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{
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struct zone *zone;
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int cpu;
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int threshold;
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int i;
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for (i = 0; i < pgdat->nr_zones; i++) {
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zone = &pgdat->node_zones[i];
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if (!zone->percpu_drift_mark)
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continue;
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threshold = (*calculate_pressure)(zone);
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for_each_possible_cpu(cpu)
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per_cpu_ptr(zone->pageset, cpu)->stat_threshold
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= threshold;
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}
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}
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/*
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* For use when we know that interrupts are disabled.
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*/
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void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
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int delta)
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{
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struct per_cpu_pageset __percpu *pcp = zone->pageset;
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s8 __percpu *p = pcp->vm_stat_diff + item;
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long x;
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long t;
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x = delta + __this_cpu_read(*p);
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t = __this_cpu_read(pcp->stat_threshold);
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if (unlikely(x > t || x < -t)) {
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zone_page_state_add(x, zone, item);
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x = 0;
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}
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__this_cpu_write(*p, x);
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}
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EXPORT_SYMBOL(__mod_zone_page_state);
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/*
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* Optimized increment and decrement functions.
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*
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* These are only for a single page and therefore can take a struct page *
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* argument instead of struct zone *. This allows the inclusion of the code
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* generated for page_zone(page) into the optimized functions.
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*
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* No overflow check is necessary and therefore the differential can be
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* incremented or decremented in place which may allow the compilers to
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* generate better code.
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* The increment or decrement is known and therefore one boundary check can
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* be omitted.
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*
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* NOTE: These functions are very performance sensitive. Change only
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* with care.
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*
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* Some processors have inc/dec instructions that are atomic vs an interrupt.
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* However, the code must first determine the differential location in a zone
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* based on the processor number and then inc/dec the counter. There is no
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* guarantee without disabling preemption that the processor will not change
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* in between and therefore the atomicity vs. interrupt cannot be exploited
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* in a useful way here.
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*/
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void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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struct per_cpu_pageset __percpu *pcp = zone->pageset;
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s8 __percpu *p = pcp->vm_stat_diff + item;
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s8 v, t;
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v = __this_cpu_inc_return(*p);
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t = __this_cpu_read(pcp->stat_threshold);
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if (unlikely(v > t)) {
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s8 overstep = t >> 1;
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zone_page_state_add(v + overstep, zone, item);
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__this_cpu_write(*p, -overstep);
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}
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}
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void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
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{
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__inc_zone_state(page_zone(page), item);
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}
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EXPORT_SYMBOL(__inc_zone_page_state);
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void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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struct per_cpu_pageset __percpu *pcp = zone->pageset;
|
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s8 __percpu *p = pcp->vm_stat_diff + item;
|
|
s8 v, t;
|
|
|
|
v = __this_cpu_dec_return(*p);
|
|
t = __this_cpu_read(pcp->stat_threshold);
|
|
if (unlikely(v < - t)) {
|
|
s8 overstep = t >> 1;
|
|
|
|
zone_page_state_add(v - overstep, zone, item);
|
|
__this_cpu_write(*p, overstep);
|
|
}
|
|
}
|
|
|
|
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
{
|
|
__dec_zone_state(page_zone(page), item);
|
|
}
|
|
EXPORT_SYMBOL(__dec_zone_page_state);
|
|
|
|
#ifdef CONFIG_CMPXCHG_LOCAL
|
|
/*
|
|
* If we have cmpxchg_local support then we do not need to incur the overhead
|
|
* that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
|
|
*
|
|
* mod_state() modifies the zone counter state through atomic per cpu
|
|
* operations.
|
|
*
|
|
* Overstep mode specifies how overstep should handled:
|
|
* 0 No overstepping
|
|
* 1 Overstepping half of threshold
|
|
* -1 Overstepping minus half of threshold
|
|
*/
|
|
static inline void mod_state(struct zone *zone,
|
|
enum zone_stat_item item, int delta, int overstep_mode)
|
|
{
|
|
struct per_cpu_pageset __percpu *pcp = zone->pageset;
|
|
s8 __percpu *p = pcp->vm_stat_diff + item;
|
|
long o, n, t, z;
|
|
|
|
do {
|
|
z = 0; /* overflow to zone counters */
|
|
|
|
/*
|
|
* The fetching of the stat_threshold is racy. We may apply
|
|
* a counter threshold to the wrong the cpu if we get
|
|
* rescheduled while executing here. However, the next
|
|
* counter update will apply the threshold again and
|
|
* therefore bring the counter under the threshold again.
|
|
*
|
|
* Most of the time the thresholds are the same anyways
|
|
* for all cpus in a zone.
|
|
*/
|
|
t = this_cpu_read(pcp->stat_threshold);
|
|
|
|
o = this_cpu_read(*p);
|
|
n = delta + o;
|
|
|
|
if (n > t || n < -t) {
|
|
int os = overstep_mode * (t >> 1) ;
|
|
|
|
/* Overflow must be added to zone counters */
|
|
z = n + os;
|
|
n = -os;
|
|
}
|
|
} while (this_cpu_cmpxchg(*p, o, n) != o);
|
|
|
|
if (z)
|
|
zone_page_state_add(z, zone, item);
|
|
}
|
|
|
|
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
|
|
int delta)
|
|
{
|
|
mod_state(zone, item, delta, 0);
|
|
}
|
|
EXPORT_SYMBOL(mod_zone_page_state);
|
|
|
|
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
{
|
|
mod_state(zone, item, 1, 1);
|
|
}
|
|
|
|
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
{
|
|
mod_state(page_zone(page), item, 1, 1);
|
|
}
|
|
EXPORT_SYMBOL(inc_zone_page_state);
|
|
|
|
void dec_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
{
|
|
mod_state(page_zone(page), item, -1, -1);
|
|
}
|
|
EXPORT_SYMBOL(dec_zone_page_state);
|
|
#else
|
|
/*
|
|
* Use interrupt disable to serialize counter updates
|
|
*/
|
|
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
|
|
int delta)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__mod_zone_page_state(zone, item, delta);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(mod_zone_page_state);
|
|
|
|
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__inc_zone_state(zone, item);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
{
|
|
unsigned long flags;
|
|
struct zone *zone;
|
|
|
|
zone = page_zone(page);
|
|
local_irq_save(flags);
|
|
__inc_zone_state(zone, item);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(inc_zone_page_state);
|
|
|
|
void dec_zone_page_state(struct page *page, enum zone_stat_item item)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__dec_zone_page_state(page, item);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(dec_zone_page_state);
|
|
#endif
|
|
|
|
/*
|
|
* Update the zone counters for one cpu.
|
|
*
|
|
* The cpu specified must be either the current cpu or a processor that
|
|
* is not online. If it is the current cpu then the execution thread must
|
|
* be pinned to the current cpu.
|
|
*
|
|
* Note that refresh_cpu_vm_stats strives to only access
|
|
* node local memory. The per cpu pagesets on remote zones are placed
|
|
* in the memory local to the processor using that pageset. So the
|
|
* loop over all zones will access a series of cachelines local to
|
|
* the processor.
|
|
*
|
|
* The call to zone_page_state_add updates the cachelines with the
|
|
* statistics in the remote zone struct as well as the global cachelines
|
|
* with the global counters. These could cause remote node cache line
|
|
* bouncing and will have to be only done when necessary.
|
|
*/
|
|
void refresh_cpu_vm_stats(int cpu)
|
|
{
|
|
struct zone *zone;
|
|
int i;
|
|
int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
|
|
|
|
for_each_populated_zone(zone) {
|
|
struct per_cpu_pageset *p;
|
|
|
|
p = per_cpu_ptr(zone->pageset, cpu);
|
|
|
|
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
|
|
if (p->vm_stat_diff[i]) {
|
|
unsigned long flags;
|
|
int v;
|
|
|
|
local_irq_save(flags);
|
|
v = p->vm_stat_diff[i];
|
|
p->vm_stat_diff[i] = 0;
|
|
local_irq_restore(flags);
|
|
atomic_long_add(v, &zone->vm_stat[i]);
|
|
global_diff[i] += v;
|
|
#ifdef CONFIG_NUMA
|
|
/* 3 seconds idle till flush */
|
|
p->expire = 3;
|
|
#endif
|
|
}
|
|
cond_resched();
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Deal with draining the remote pageset of this
|
|
* processor
|
|
*
|
|
* Check if there are pages remaining in this pageset
|
|
* if not then there is nothing to expire.
|
|
*/
|
|
if (!p->expire || !p->pcp.count)
|
|
continue;
|
|
|
|
/*
|
|
* We never drain zones local to this processor.
|
|
*/
|
|
if (zone_to_nid(zone) == numa_node_id()) {
|
|
p->expire = 0;
|
|
continue;
|
|
}
|
|
|
|
p->expire--;
|
|
if (p->expire)
|
|
continue;
|
|
|
|
if (p->pcp.count)
|
|
drain_zone_pages(zone, &p->pcp);
|
|
#endif
|
|
}
|
|
|
|
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
|
|
if (global_diff[i])
|
|
atomic_long_add(global_diff[i], &vm_stat[i]);
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* zonelist = the list of zones passed to the allocator
|
|
* z = the zone from which the allocation occurred.
|
|
*
|
|
* Must be called with interrupts disabled.
|
|
*
|
|
* When __GFP_OTHER_NODE is set assume the node of the preferred
|
|
* zone is the local node. This is useful for daemons who allocate
|
|
* memory on behalf of other processes.
|
|
*/
|
|
void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
|
|
{
|
|
if (z->zone_pgdat == preferred_zone->zone_pgdat) {
|
|
__inc_zone_state(z, NUMA_HIT);
|
|
} else {
|
|
__inc_zone_state(z, NUMA_MISS);
|
|
__inc_zone_state(preferred_zone, NUMA_FOREIGN);
|
|
}
|
|
if (z->node == ((flags & __GFP_OTHER_NODE) ?
|
|
preferred_zone->node : numa_node_id()))
|
|
__inc_zone_state(z, NUMA_LOCAL);
|
|
else
|
|
__inc_zone_state(z, NUMA_OTHER);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_COMPACTION
|
|
|
|
struct contig_page_info {
|
|
unsigned long free_pages;
|
|
unsigned long free_blocks_total;
|
|
unsigned long free_blocks_suitable;
|
|
};
|
|
|
|
/*
|
|
* Calculate the number of free pages in a zone, how many contiguous
|
|
* pages are free and how many are large enough to satisfy an allocation of
|
|
* the target size. Note that this function makes no attempt to estimate
|
|
* how many suitable free blocks there *might* be if MOVABLE pages were
|
|
* migrated. Calculating that is possible, but expensive and can be
|
|
* figured out from userspace
|
|
*/
|
|
static void fill_contig_page_info(struct zone *zone,
|
|
unsigned int suitable_order,
|
|
struct contig_page_info *info)
|
|
{
|
|
unsigned int order;
|
|
|
|
info->free_pages = 0;
|
|
info->free_blocks_total = 0;
|
|
info->free_blocks_suitable = 0;
|
|
|
|
for (order = 0; order < MAX_ORDER; order++) {
|
|
unsigned long blocks;
|
|
|
|
/* Count number of free blocks */
|
|
blocks = zone->free_area[order].nr_free;
|
|
info->free_blocks_total += blocks;
|
|
|
|
/* Count free base pages */
|
|
info->free_pages += blocks << order;
|
|
|
|
/* Count the suitable free blocks */
|
|
if (order >= suitable_order)
|
|
info->free_blocks_suitable += blocks <<
|
|
(order - suitable_order);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* A fragmentation index only makes sense if an allocation of a requested
|
|
* size would fail. If that is true, the fragmentation index indicates
|
|
* whether external fragmentation or a lack of memory was the problem.
|
|
* The value can be used to determine if page reclaim or compaction
|
|
* should be used
|
|
*/
|
|
static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
|
|
{
|
|
unsigned long requested = 1UL << order;
|
|
|
|
if (!info->free_blocks_total)
|
|
return 0;
|
|
|
|
/* Fragmentation index only makes sense when a request would fail */
|
|
if (info->free_blocks_suitable)
|
|
return -1000;
|
|
|
|
/*
|
|
* Index is between 0 and 1 so return within 3 decimal places
|
|
*
|
|
* 0 => allocation would fail due to lack of memory
|
|
* 1 => allocation would fail due to fragmentation
|
|
*/
|
|
return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
|
|
}
|
|
|
|
/* Same as __fragmentation index but allocs contig_page_info on stack */
|
|
int fragmentation_index(struct zone *zone, unsigned int order)
|
|
{
|
|
struct contig_page_info info;
|
|
|
|
fill_contig_page_info(zone, order, &info);
|
|
return __fragmentation_index(order, &info);
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/seq_file.h>
|
|
|
|
static char * const migratetype_names[MIGRATE_TYPES] = {
|
|
"Unmovable",
|
|
"Reclaimable",
|
|
"Movable",
|
|
"Reserve",
|
|
"Isolate",
|
|
};
|
|
|
|
static void *frag_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
pg_data_t *pgdat;
|
|
loff_t node = *pos;
|
|
for (pgdat = first_online_pgdat();
|
|
pgdat && node;
|
|
pgdat = next_online_pgdat(pgdat))
|
|
--node;
|
|
|
|
return pgdat;
|
|
}
|
|
|
|
static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
(*pos)++;
|
|
return next_online_pgdat(pgdat);
|
|
}
|
|
|
|
static void frag_stop(struct seq_file *m, void *arg)
|
|
{
|
|
}
|
|
|
|
/* Walk all the zones in a node and print using a callback */
|
|
static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
|
|
void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
|
|
{
|
|
struct zone *zone;
|
|
struct zone *node_zones = pgdat->node_zones;
|
|
unsigned long flags;
|
|
|
|
for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
|
|
if (!populated_zone(zone))
|
|
continue;
|
|
|
|
spin_lock_irqsave(&zone->lock, flags);
|
|
print(m, pgdat, zone);
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
|
|
#ifdef CONFIG_ZONE_DMA
|
|
#define TEXT_FOR_DMA(xx) xx "_dma",
|
|
#else
|
|
#define TEXT_FOR_DMA(xx)
|
|
#endif
|
|
|
|
#ifdef CONFIG_ZONE_DMA32
|
|
#define TEXT_FOR_DMA32(xx) xx "_dma32",
|
|
#else
|
|
#define TEXT_FOR_DMA32(xx)
|
|
#endif
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
#define TEXT_FOR_HIGHMEM(xx) xx "_high",
|
|
#else
|
|
#define TEXT_FOR_HIGHMEM(xx)
|
|
#endif
|
|
|
|
#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
|
|
TEXT_FOR_HIGHMEM(xx) xx "_movable",
|
|
|
|
const char * const vmstat_text[] = {
|
|
/* Zoned VM counters */
|
|
"nr_free_pages",
|
|
"nr_inactive_anon",
|
|
"nr_active_anon",
|
|
"nr_inactive_file",
|
|
"nr_active_file",
|
|
"nr_unevictable",
|
|
"nr_mlock",
|
|
"nr_anon_pages",
|
|
"nr_mapped",
|
|
"nr_file_pages",
|
|
"nr_dirty",
|
|
"nr_writeback",
|
|
"nr_slab_reclaimable",
|
|
"nr_slab_unreclaimable",
|
|
"nr_page_table_pages",
|
|
"nr_kernel_stack",
|
|
"nr_unstable",
|
|
"nr_bounce",
|
|
"nr_vmscan_write",
|
|
"nr_vmscan_write_skip",
|
|
"nr_writeback_temp",
|
|
"nr_isolated_anon",
|
|
"nr_isolated_file",
|
|
"nr_shmem",
|
|
"nr_dirtied",
|
|
"nr_written",
|
|
|
|
#ifdef CONFIG_NUMA
|
|
"numa_hit",
|
|
"numa_miss",
|
|
"numa_foreign",
|
|
"numa_interleave",
|
|
"numa_local",
|
|
"numa_other",
|
|
#endif
|
|
"nr_anon_transparent_hugepages",
|
|
"nr_dirty_threshold",
|
|
"nr_dirty_background_threshold",
|
|
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
"pgpgin",
|
|
"pgpgout",
|
|
"pswpin",
|
|
"pswpout",
|
|
|
|
TEXTS_FOR_ZONES("pgalloc")
|
|
|
|
"pgfree",
|
|
"pgactivate",
|
|
"pgdeactivate",
|
|
|
|
"pgfault",
|
|
"pgmajfault",
|
|
|
|
TEXTS_FOR_ZONES("pgrefill")
|
|
TEXTS_FOR_ZONES("pgsteal")
|
|
TEXTS_FOR_ZONES("pgscan_kswapd")
|
|
TEXTS_FOR_ZONES("pgscan_direct")
|
|
|
|
#ifdef CONFIG_NUMA
|
|
"zone_reclaim_failed",
|
|
#endif
|
|
"pginodesteal",
|
|
"slabs_scanned",
|
|
"kswapd_steal",
|
|
"kswapd_inodesteal",
|
|
"kswapd_low_wmark_hit_quickly",
|
|
"kswapd_high_wmark_hit_quickly",
|
|
"kswapd_skip_congestion_wait",
|
|
"pageoutrun",
|
|
"allocstall",
|
|
|
|
"pgrotated",
|
|
|
|
#ifdef CONFIG_COMPACTION
|
|
"compact_blocks_moved",
|
|
"compact_pages_moved",
|
|
"compact_pagemigrate_failed",
|
|
"compact_stall",
|
|
"compact_fail",
|
|
"compact_success",
|
|
#endif
|
|
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
"htlb_buddy_alloc_success",
|
|
"htlb_buddy_alloc_fail",
|
|
#endif
|
|
"unevictable_pgs_culled",
|
|
"unevictable_pgs_scanned",
|
|
"unevictable_pgs_rescued",
|
|
"unevictable_pgs_mlocked",
|
|
"unevictable_pgs_munlocked",
|
|
"unevictable_pgs_cleared",
|
|
"unevictable_pgs_stranded",
|
|
"unevictable_pgs_mlockfreed",
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
"thp_fault_alloc",
|
|
"thp_fault_fallback",
|
|
"thp_collapse_alloc",
|
|
"thp_collapse_alloc_failed",
|
|
"thp_split",
|
|
#endif
|
|
|
|
#endif /* CONFIG_VM_EVENTS_COUNTERS */
|
|
};
|
|
#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
|
|
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
|
|
struct zone *zone)
|
|
{
|
|
int order;
|
|
|
|
seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
|
|
for (order = 0; order < MAX_ORDER; ++order)
|
|
seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
/*
|
|
* This walks the free areas for each zone.
|
|
*/
|
|
static int frag_show(struct seq_file *m, void *arg)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
walk_zones_in_node(m, pgdat, frag_show_print);
|
|
return 0;
|
|
}
|
|
|
|
static void pagetypeinfo_showfree_print(struct seq_file *m,
|
|
pg_data_t *pgdat, struct zone *zone)
|
|
{
|
|
int order, mtype;
|
|
|
|
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
|
|
seq_printf(m, "Node %4d, zone %8s, type %12s ",
|
|
pgdat->node_id,
|
|
zone->name,
|
|
migratetype_names[mtype]);
|
|
for (order = 0; order < MAX_ORDER; ++order) {
|
|
unsigned long freecount = 0;
|
|
struct free_area *area;
|
|
struct list_head *curr;
|
|
|
|
area = &(zone->free_area[order]);
|
|
|
|
list_for_each(curr, &area->free_list[mtype])
|
|
freecount++;
|
|
seq_printf(m, "%6lu ", freecount);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
}
|
|
|
|
/* Print out the free pages at each order for each migatetype */
|
|
static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
|
|
{
|
|
int order;
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
/* Print header */
|
|
seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
|
|
for (order = 0; order < MAX_ORDER; ++order)
|
|
seq_printf(m, "%6d ", order);
|
|
seq_putc(m, '\n');
|
|
|
|
walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void pagetypeinfo_showblockcount_print(struct seq_file *m,
|
|
pg_data_t *pgdat, struct zone *zone)
|
|
{
|
|
int mtype;
|
|
unsigned long pfn;
|
|
unsigned long start_pfn = zone->zone_start_pfn;
|
|
unsigned long end_pfn = start_pfn + zone->spanned_pages;
|
|
unsigned long count[MIGRATE_TYPES] = { 0, };
|
|
|
|
for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pfn))
|
|
continue;
|
|
|
|
page = pfn_to_page(pfn);
|
|
|
|
/* Watch for unexpected holes punched in the memmap */
|
|
if (!memmap_valid_within(pfn, page, zone))
|
|
continue;
|
|
|
|
mtype = get_pageblock_migratetype(page);
|
|
|
|
if (mtype < MIGRATE_TYPES)
|
|
count[mtype]++;
|
|
}
|
|
|
|
/* Print counts */
|
|
seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
|
|
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
|
|
seq_printf(m, "%12lu ", count[mtype]);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
/* Print out the free pages at each order for each migratetype */
|
|
static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
|
|
{
|
|
int mtype;
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
seq_printf(m, "\n%-23s", "Number of blocks type ");
|
|
for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
|
|
seq_printf(m, "%12s ", migratetype_names[mtype]);
|
|
seq_putc(m, '\n');
|
|
walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This prints out statistics in relation to grouping pages by mobility.
|
|
* It is expensive to collect so do not constantly read the file.
|
|
*/
|
|
static int pagetypeinfo_show(struct seq_file *m, void *arg)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
/* check memoryless node */
|
|
if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
|
|
return 0;
|
|
|
|
seq_printf(m, "Page block order: %d\n", pageblock_order);
|
|
seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
|
|
seq_putc(m, '\n');
|
|
pagetypeinfo_showfree(m, pgdat);
|
|
pagetypeinfo_showblockcount(m, pgdat);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations fragmentation_op = {
|
|
.start = frag_start,
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = frag_show,
|
|
};
|
|
|
|
static int fragmentation_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &fragmentation_op);
|
|
}
|
|
|
|
static const struct file_operations fragmentation_file_operations = {
|
|
.open = fragmentation_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static const struct seq_operations pagetypeinfo_op = {
|
|
.start = frag_start,
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = pagetypeinfo_show,
|
|
};
|
|
|
|
static int pagetypeinfo_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &pagetypeinfo_op);
|
|
}
|
|
|
|
static const struct file_operations pagetypeinfo_file_ops = {
|
|
.open = pagetypeinfo_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
|
|
struct zone *zone)
|
|
{
|
|
int i;
|
|
seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
|
|
seq_printf(m,
|
|
"\n pages free %lu"
|
|
"\n min %lu"
|
|
"\n low %lu"
|
|
"\n high %lu"
|
|
"\n scanned %lu"
|
|
"\n spanned %lu"
|
|
"\n present %lu",
|
|
zone_page_state(zone, NR_FREE_PAGES),
|
|
min_wmark_pages(zone),
|
|
low_wmark_pages(zone),
|
|
high_wmark_pages(zone),
|
|
zone->pages_scanned,
|
|
zone->spanned_pages,
|
|
zone->present_pages);
|
|
|
|
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
|
|
seq_printf(m, "\n %-12s %lu", vmstat_text[i],
|
|
zone_page_state(zone, i));
|
|
|
|
seq_printf(m,
|
|
"\n protection: (%lu",
|
|
zone->lowmem_reserve[0]);
|
|
for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
|
|
seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
|
|
seq_printf(m,
|
|
")"
|
|
"\n pagesets");
|
|
for_each_online_cpu(i) {
|
|
struct per_cpu_pageset *pageset;
|
|
|
|
pageset = per_cpu_ptr(zone->pageset, i);
|
|
seq_printf(m,
|
|
"\n cpu: %i"
|
|
"\n count: %i"
|
|
"\n high: %i"
|
|
"\n batch: %i",
|
|
i,
|
|
pageset->pcp.count,
|
|
pageset->pcp.high,
|
|
pageset->pcp.batch);
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(m, "\n vm stats threshold: %d",
|
|
pageset->stat_threshold);
|
|
#endif
|
|
}
|
|
seq_printf(m,
|
|
"\n all_unreclaimable: %u"
|
|
"\n start_pfn: %lu"
|
|
"\n inactive_ratio: %u",
|
|
zone->all_unreclaimable,
|
|
zone->zone_start_pfn,
|
|
zone->inactive_ratio);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
/*
|
|
* Output information about zones in @pgdat.
|
|
*/
|
|
static int zoneinfo_show(struct seq_file *m, void *arg)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
walk_zones_in_node(m, pgdat, zoneinfo_show_print);
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations zoneinfo_op = {
|
|
.start = frag_start, /* iterate over all zones. The same as in
|
|
* fragmentation. */
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = zoneinfo_show,
|
|
};
|
|
|
|
static int zoneinfo_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &zoneinfo_op);
|
|
}
|
|
|
|
static const struct file_operations proc_zoneinfo_file_operations = {
|
|
.open = zoneinfo_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
enum writeback_stat_item {
|
|
NR_DIRTY_THRESHOLD,
|
|
NR_DIRTY_BG_THRESHOLD,
|
|
NR_VM_WRITEBACK_STAT_ITEMS,
|
|
};
|
|
|
|
static void *vmstat_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
unsigned long *v;
|
|
int i, stat_items_size;
|
|
|
|
if (*pos >= ARRAY_SIZE(vmstat_text))
|
|
return NULL;
|
|
stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
|
|
NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
|
|
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
stat_items_size += sizeof(struct vm_event_state);
|
|
#endif
|
|
|
|
v = kmalloc(stat_items_size, GFP_KERNEL);
|
|
m->private = v;
|
|
if (!v)
|
|
return ERR_PTR(-ENOMEM);
|
|
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
|
|
v[i] = global_page_state(i);
|
|
v += NR_VM_ZONE_STAT_ITEMS;
|
|
|
|
global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
|
|
v + NR_DIRTY_THRESHOLD);
|
|
v += NR_VM_WRITEBACK_STAT_ITEMS;
|
|
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
all_vm_events(v);
|
|
v[PGPGIN] /= 2; /* sectors -> kbytes */
|
|
v[PGPGOUT] /= 2;
|
|
#endif
|
|
return (unsigned long *)m->private + *pos;
|
|
}
|
|
|
|
static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
if (*pos >= ARRAY_SIZE(vmstat_text))
|
|
return NULL;
|
|
return (unsigned long *)m->private + *pos;
|
|
}
|
|
|
|
static int vmstat_show(struct seq_file *m, void *arg)
|
|
{
|
|
unsigned long *l = arg;
|
|
unsigned long off = l - (unsigned long *)m->private;
|
|
|
|
seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
|
|
return 0;
|
|
}
|
|
|
|
static void vmstat_stop(struct seq_file *m, void *arg)
|
|
{
|
|
kfree(m->private);
|
|
m->private = NULL;
|
|
}
|
|
|
|
static const struct seq_operations vmstat_op = {
|
|
.start = vmstat_start,
|
|
.next = vmstat_next,
|
|
.stop = vmstat_stop,
|
|
.show = vmstat_show,
|
|
};
|
|
|
|
static int vmstat_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &vmstat_op);
|
|
}
|
|
|
|
static const struct file_operations proc_vmstat_file_operations = {
|
|
.open = vmstat_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
#ifdef CONFIG_SMP
|
|
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
|
|
int sysctl_stat_interval __read_mostly = HZ;
|
|
|
|
static void vmstat_update(struct work_struct *w)
|
|
{
|
|
refresh_cpu_vm_stats(smp_processor_id());
|
|
schedule_delayed_work(&__get_cpu_var(vmstat_work),
|
|
round_jiffies_relative(sysctl_stat_interval));
|
|
}
|
|
|
|
static void __cpuinit start_cpu_timer(int cpu)
|
|
{
|
|
struct delayed_work *work = &per_cpu(vmstat_work, cpu);
|
|
|
|
INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
|
|
schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
|
|
}
|
|
|
|
/*
|
|
* Use the cpu notifier to insure that the thresholds are recalculated
|
|
* when necessary.
|
|
*/
|
|
static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
long cpu = (long)hcpu;
|
|
|
|
switch (action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
refresh_zone_stat_thresholds();
|
|
start_cpu_timer(cpu);
|
|
node_set_state(cpu_to_node(cpu), N_CPU);
|
|
break;
|
|
case CPU_DOWN_PREPARE:
|
|
case CPU_DOWN_PREPARE_FROZEN:
|
|
cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
|
|
per_cpu(vmstat_work, cpu).work.func = NULL;
|
|
break;
|
|
case CPU_DOWN_FAILED:
|
|
case CPU_DOWN_FAILED_FROZEN:
|
|
start_cpu_timer(cpu);
|
|
break;
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
refresh_zone_stat_thresholds();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __cpuinitdata vmstat_notifier =
|
|
{ &vmstat_cpuup_callback, NULL, 0 };
|
|
#endif
|
|
|
|
static int __init setup_vmstat(void)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
int cpu;
|
|
|
|
register_cpu_notifier(&vmstat_notifier);
|
|
|
|
for_each_online_cpu(cpu)
|
|
start_cpu_timer(cpu);
|
|
#endif
|
|
#ifdef CONFIG_PROC_FS
|
|
proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
|
|
proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
|
|
proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
|
|
proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
|
|
#endif
|
|
return 0;
|
|
}
|
|
module_init(setup_vmstat)
|
|
|
|
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
|
|
#include <linux/debugfs.h>
|
|
|
|
static struct dentry *extfrag_debug_root;
|
|
|
|
/*
|
|
* Return an index indicating how much of the available free memory is
|
|
* unusable for an allocation of the requested size.
|
|
*/
|
|
static int unusable_free_index(unsigned int order,
|
|
struct contig_page_info *info)
|
|
{
|
|
/* No free memory is interpreted as all free memory is unusable */
|
|
if (info->free_pages == 0)
|
|
return 1000;
|
|
|
|
/*
|
|
* Index should be a value between 0 and 1. Return a value to 3
|
|
* decimal places.
|
|
*
|
|
* 0 => no fragmentation
|
|
* 1 => high fragmentation
|
|
*/
|
|
return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
|
|
|
|
}
|
|
|
|
static void unusable_show_print(struct seq_file *m,
|
|
pg_data_t *pgdat, struct zone *zone)
|
|
{
|
|
unsigned int order;
|
|
int index;
|
|
struct contig_page_info info;
|
|
|
|
seq_printf(m, "Node %d, zone %8s ",
|
|
pgdat->node_id,
|
|
zone->name);
|
|
for (order = 0; order < MAX_ORDER; ++order) {
|
|
fill_contig_page_info(zone, order, &info);
|
|
index = unusable_free_index(order, &info);
|
|
seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
|
|
}
|
|
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
/*
|
|
* Display unusable free space index
|
|
*
|
|
* The unusable free space index measures how much of the available free
|
|
* memory cannot be used to satisfy an allocation of a given size and is a
|
|
* value between 0 and 1. The higher the value, the more of free memory is
|
|
* unusable and by implication, the worse the external fragmentation is. This
|
|
* can be expressed as a percentage by multiplying by 100.
|
|
*/
|
|
static int unusable_show(struct seq_file *m, void *arg)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
/* check memoryless node */
|
|
if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
|
|
return 0;
|
|
|
|
walk_zones_in_node(m, pgdat, unusable_show_print);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations unusable_op = {
|
|
.start = frag_start,
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = unusable_show,
|
|
};
|
|
|
|
static int unusable_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &unusable_op);
|
|
}
|
|
|
|
static const struct file_operations unusable_file_ops = {
|
|
.open = unusable_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static void extfrag_show_print(struct seq_file *m,
|
|
pg_data_t *pgdat, struct zone *zone)
|
|
{
|
|
unsigned int order;
|
|
int index;
|
|
|
|
/* Alloc on stack as interrupts are disabled for zone walk */
|
|
struct contig_page_info info;
|
|
|
|
seq_printf(m, "Node %d, zone %8s ",
|
|
pgdat->node_id,
|
|
zone->name);
|
|
for (order = 0; order < MAX_ORDER; ++order) {
|
|
fill_contig_page_info(zone, order, &info);
|
|
index = __fragmentation_index(order, &info);
|
|
seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
|
|
}
|
|
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
/*
|
|
* Display fragmentation index for orders that allocations would fail for
|
|
*/
|
|
static int extfrag_show(struct seq_file *m, void *arg)
|
|
{
|
|
pg_data_t *pgdat = (pg_data_t *)arg;
|
|
|
|
walk_zones_in_node(m, pgdat, extfrag_show_print);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations extfrag_op = {
|
|
.start = frag_start,
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = extfrag_show,
|
|
};
|
|
|
|
static int extfrag_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &extfrag_op);
|
|
}
|
|
|
|
static const struct file_operations extfrag_file_ops = {
|
|
.open = extfrag_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init extfrag_debug_init(void)
|
|
{
|
|
extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
|
|
if (!extfrag_debug_root)
|
|
return -ENOMEM;
|
|
|
|
if (!debugfs_create_file("unusable_index", 0444,
|
|
extfrag_debug_root, NULL, &unusable_file_ops))
|
|
return -ENOMEM;
|
|
|
|
if (!debugfs_create_file("extfrag_index", 0444,
|
|
extfrag_debug_root, NULL, &extfrag_file_ops))
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
module_init(extfrag_debug_init);
|
|
#endif
|