Commit Graph

6644 Commits

Author SHA1 Message Date
Badari Pulavarty
e63e1e5a6b hugetlbfs read() support
Support for reading from hugetlbfs files.  libhugetlbfs lets application
text/data to be placed in large pages.  When we do that, oprofile doesn't
work - since libbfd tries to read from it.

This code is very similar to what do_generic_mapping_read() does, but I
can't use it since it has PAGE_CACHE_SIZE assumptions.

[akpm@linux-foundation.org: cleanups, fix leak]
[bunk@stusta.de: make hugetlbfs_read() static]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: William Irwin <bill.irwin@oracle.com>
Tested-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:03 -07:00
Ken Chen
7aa91e1040 hugetlb: allow extending ftruncate on hugetlbfs
For historical reason, expanding ftruncate that increases file size on
hugetlbfs is not allowed due to pages were pre-faulted and lack of fault
handler.  Now that we have demand faulting on hugetlb since 2.6.15, there
is no reason to hold back that limitation.

This will make hugetlbfs behave more like a normal fs.  I'm writing a user
level code that uses hugetlbfs but will fall back to tmpfs if there are no
hugetlb page available in the system.  Having hugetlbfs specific ftruncate
behavior is a bit quirky and I would like to remove that artificial
limitation.

Signed-off-by: <kenchen@google.com>
Acked-by: Wiliam Irwin <wli@holomorphy.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:02 -07:00
Mel Gorman
467c996c1e Print out statistics in relation to fragmentation avoidance to /proc/pagetypeinfo
This patch provides fragmentation avoidance statistics via /proc/pagetypeinfo.
 The information is collected only on request so there is no runtime overhead.
 The statistics are in three parts:

The first part prints information on the size of blocks that pages are
being grouped on and looks like

Page block order: 10
Pages per block:  1024

The second part is a more detailed version of /proc/buddyinfo and looks like

Free pages count per migrate type at order       0      1      2      3      4      5      6      7      8      9     10
Node    0, zone      DMA, type    Unmovable      0      0      0      0      0      0      0      0      0      0      0
Node    0, zone      DMA, type  Reclaimable      1      0      0      0      0      0      0      0      0      0      0
Node    0, zone      DMA, type      Movable      0      0      0      0      0      0      0      0      0      0      0
Node    0, zone      DMA, type      Reserve      0      4      4      0      0      0      0      1      0      1      0
Node    0, zone   Normal, type    Unmovable    111      8      4      4      2      3      1      0      0      0      0
Node    0, zone   Normal, type  Reclaimable    293     89      8      0      0      0      0      0      0      0      0
Node    0, zone   Normal, type      Movable      1      6     13      9      7      6      3      0      0      0      0
Node    0, zone   Normal, type      Reserve      0      0      0      0      0      0      0      0      0      0      4

The third part looks like

Number of blocks type     Unmovable  Reclaimable      Movable      Reserve
Node 0, zone      DMA            0            1            2            1
Node 0, zone   Normal            3           17           94            4

To walk the zones within a node with interrupts disabled, walk_zones_in_node()
is introduced and shared between /proc/buddyinfo, /proc/zoneinfo and
/proc/pagetypeinfo to reduce code duplication.  It seems specific to what
vmstat.c requires but could be broken out as a general utility function in
mmzone.c if there were other other potential users.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:00 -07:00
Mel Gorman
e12ba74d8f Group short-lived and reclaimable kernel allocations
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:00 -07:00
Nick Piggin
55144768e1 fs: remove some AOP_TRUNCATED_PAGE
prepare/commit_write no longer returns AOP_TRUNCATED_PAGE since OCFS2 and
GFS2 were converted to the new aops, so we can make some simplifications
for that.

[michal.k.k.piotrowski@gmail.com: fix warning]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Nick Piggin
03158cd7eb fs: restore nobh
Implement nobh in new aops.  This is a bit tricky.  FWIW, nobh_truncate is
now implemented in a way that does not create blocks in sparse regions,
which is a silly thing for it to have been doing (isn't it?)

ext2 survives fsx and fsstress. jfs is converted as well... ext3
should be easy to do (but not done yet).

[akpm@linux-foundation.org: coding-style fixes]
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Nick Piggin
b6af1bcd87 ocfs2: convert to new aops
Plug ocfs2 into the ->write_begin and ->write_end aops.

A bunch of custom code is now gone - the iovec iteration stuff during write
and the ocfs2 splice write actor.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Nick Piggin
f2b6a16eb8 fs: affs convert to new aops
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:58 -07:00
Nick Piggin
b4585729f0 fs: adfs convert to new aops
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
d5c5f84ba9 jfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
4a66af9eaa minixfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Andries Brouwer <Andries.Brouwer@cwi.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
26a6441aad sysv: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
be021ee41a udf: convert to new aops
Convert udf to new aops.  Also seem to have fixed pagecache corruption in
udf_adinicb_commit_write -- page was marked uptodate when it is not.  Also,
fixed the silly setup where prepare_write was doing a kmap to be used in
commit_write: just do kmap_atomic in write_end.  Use libfs helpers to make
this easier.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: <bfennema@falcon.csc.calpoly.edu>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
82b9d1d0da ufs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
205c109a7a jffs2: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
ae361ff46b hostfs: convert to new aops
This also gets rid of a lot of useless read_file stuff. And also
optimises the full page write case by marking a !uptodate page uptodate.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
5e6f58a1d7 fuse: convert to new aops
[mszeredi]
 - don't send zero length write requests
 - it is not legal for the filesystem to return with zero written bytes

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
fb53b30948 smbfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
4899f9c852 nfs: convert to new aops
[akpm@linux-foundation.org: fix against git-nfs]
[peterz@infradead.org: fix against git-nfs]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:57 -07:00
Nick Piggin
a20fa20c54 With reiserfs no longer using the weird generic_cont_expand, remove it completely.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Vladimir Saveliev
f7557e8f7f reiserfs: use generic_cont_expand_simple
This patch makes reiserfs to use AOP_FLAG_CONT_EXPAND
in order to get rid of the special generic_cont_expand routine

Signed-off-by: Vladimir Saveliev <vs@namesys.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Vladimir Saveliev
ba9d8cec6c reiserfs: convert to new aops
Convert reiserfs to new aops

Signed-off-by: Vladimir Saveliev <vs@namesys.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Vladimir Saveliev
797b4cffdf reiserfs: use generic write
Make reiserfs to write via generic routines.
Original reiserfs write optimized for big writes is deadlock rone

Signed-off-by: Vladimir Saveliev <vs@namesys.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
f870618428 qnx4: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Anders Larsen <al@alarsen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
eedcbba5e0 bfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
d6091b7201 hpfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
7c0efc6277 hfsplus: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
7903d9eed8 hfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:56 -07:00
Nick Piggin
d7777a25a0 fat: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
89e107877b fs: new cont helpers
Rework the generic block "cont" routines to handle the new aops.  Supporting
cont_prepare_write would take quite a lot of code to support, so remove it
instead (and we later convert all filesystems to use it).

write_begin gets passed AOP_FLAG_CONT_EXPAND when called from
generic_cont_expand, so filesystems can avoid the old hacks they used.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Steven Whitehouse
7765ec26ae gfs2: convert to new aops
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
d79689c703 xfs: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
bfc1af650a ext4: convert to new aops
Convert ext4 to use write_begin()/write_end() methods.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dmitriy Monakhov <dmonakhov@sw.ru>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
f4fc66a894 ext3: convert to new aops
Various fixes and improvements

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
f34fb6eccc ext2: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
6272b5a586 block_dev: convert to new aops
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
800d15a53e implement simple fs aops
Implement new aops for some of the simpler filesystems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
afddba49d1 fs: introduce write_begin, write_end, and perform_write aops
These are intended to replace prepare_write and commit_write with more
flexible alternatives that are also able to avoid the buffered write
deadlock problems efficiently (which prepare_write is unable to do).

[mark.fasheh@oracle.com: API design contributions, code review and fixes]
[akpm@linux-foundation.org: various fixes]
[dmonakhov@sw.ru: new aop block_write_begin fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
637aff46f9 fs: fix data-loss on error
New buffers against uptodate pages are simply be marked uptodate, while the
buffer_new bit remains set.  This causes error-case code to zero out parts of
those buffers because it thinks they contain stale data: wrong, they are
actually uptodate so this is a data loss situation.

Fix this by actually clearning buffer_new and marking the buffer dirty.  It
makes sense to always clear buffer_new before setting a buffer uptodate.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:55 -07:00
Nick Piggin
eb2be18931 mm: buffered write cleanup
Quite a bit of code is used in maintaining these "cached pages" that are
probably pretty unlikely to get used. It would require a narrow race where
the page is inserted concurrently while this process is allocating a page
in order to create the spare page. Then a multi-page write into an uncached
part of the file, to make use of it.

Next, the buffered write path (and others) uses its own LRU pagevec when it
should be just using the per-CPU LRU pagevec (which will cut down on both data
and code size cacheline footprint). Also, these private LRU pagevecs are
emptied after just a very short time, in contrast with the per-CPU pagevecs
that are persistent. Net result: 7.3 times fewer lru_lock acquisitions required
to add the pages to pagecache for a bulk write (in 4K chunks).

[this gets rid of some cond_resched() calls in readahead.c and mpage.c due
 to clashes in -mm. What put them there, and why? ]

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:54 -07:00
Nick Piggin
a4b0672db3 fs: fix nobh error handling
nobh mode error handling is not just pretty slack, it's wrong.

One cannot zero out the whole page to ensure new blocks are zeroed, because
it just brings the whole page "uptodate" with zeroes even if that may not
be the correct uptodate data.  Also, other parts of the page may already
contain dirty data which would get lost by zeroing it out.  Thirdly, the
writeback of zeroes to the new blocks will also erase existing blocks.  All
these conditions are pagecache and/or filesystem corruption.

The problem comes about because we didn't keep track of which buffers
actually are new or old.  However it is not enough just to keep only this
state, because at the point we start dirtying parts of the page (new
blocks, with zeroes), the handling of IO errors becomes impossible without
buffers because the page may only be partially uptodate, in which case the
page flags allone cannot capture the state of the parts of the page.

So allocate all buffers for the page upfront, but leave them unattached so
that they don't pick up any other references and can be freed when we're
done.  If the error path is hit, then zero the new buffers as the regular
buffer path does, then attach the buffers to the page so that it can
actually be written out correctly and be subject to the normal IO error
handling paths.

As an upshot, we save 1K of kernel stack on ia64 or powerpc 64K page
systems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:54 -07:00
Dmitry Monakhov
68671f35fe mm: add end_buffer_read helper function
Move duplicated code from end_buffer_read_XXX methods to separate helper
function.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:53 -07:00
Nick Piggin
557ed1fa26 remove ZERO_PAGE
The commit b5810039a5 contains the note

  A last caveat: the ZERO_PAGE is now refcounted and managed with rmap
  (and thus mapcounted and count towards shared rss).  These writes to
  the struct page could cause excessive cacheline bouncing on big
  systems.  There are a number of ways this could be addressed if it is
  an issue.

And indeed this cacheline bouncing has shown up on large SGI systems.
There was a situation where an Altix system was essentially livelocked
tearing down ZERO_PAGE pagetables when an HPC app aborted during startup.
This situation can be avoided in userspace, but it does highlight the
potential scalability problem with refcounting ZERO_PAGE, and corner
cases where it can really hurt (we don't want the system to livelock!).

There are several broad ways to fix this problem:
1. add back some special casing to avoid refcounting ZERO_PAGE
2. per-node or per-cpu ZERO_PAGES
3. remove the ZERO_PAGE completely

I will argue for 3. The others should also fix the problem, but they
result in more complex code than does 3, with little or no real benefit
that I can see.

Why? Inserting a ZERO_PAGE for anonymous read faults appears to be a
false optimisation: if an application is performance critical, it would
not be doing many read faults of new memory, or at least it could be
expected to write to that memory soon afterwards. If cache or memory use
is critical, it should not be working with a significant number of
ZERO_PAGEs anyway (a more compact representation of zeroes should be
used).

As a sanity check -- mesuring on my desktop system, there are never many
mappings to the ZERO_PAGE (eg. 2 or 3), thus memory usage here should not
increase much without it.

When running a make -j4 kernel compile on my dual core system, there are
about 1,000 mappings to the ZERO_PAGE created per second, but about 1,000
ZERO_PAGE COW faults per second (less than 1 ZERO_PAGE mapping per second
is torn down without being COWed). So removing ZERO_PAGE will save 1,000
page faults per second when running kbuild, while keeping it only saves
less than 1 page clearing operation per second. 1 page clear is cheaper
than a thousand faults, presumably, so there isn't an obvious loss.

Neither the logical argument nor these basic tests give a guarantee of no
regressions. However, this is a reasonable opportunity to try to remove
the ZERO_PAGE from the pagefault path. If it is found to cause regressions,
we can reintroduce it and just avoid refcounting it.

The /dev/zero ZERO_PAGE usage and TLB tricks also get nuked.  I don't see
much use to them except on benchmarks.  All other users of ZERO_PAGE are
converted just to use ZERO_PAGE(0) for simplicity. We can look at
replacing them all and maybe ripping out ZERO_PAGE completely when we are
more satisfied with this solution.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus "snif" Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:53 -07:00
Fengguang Wu
f4e6b498d6 readahead: combine file_ra_state.prev_index/prev_offset into prev_pos
Combine the file_ra_state members
				unsigned long prev_index
				unsigned int prev_offset
into
				loff_t prev_pos

It is more consistent and better supports huge files.

Thanks to Peter for the nice proposal!

[akpm@linux-foundation.org: fix shift overflow]
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:52 -07:00
Randy Dunlap
e6716b87d5 docbook: fix filesystems content
Fix filesystems docbook warnings.

Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'name'
Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'mode'
Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'parent'
Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'value'
Warning(linux-2.6.23-git8//include/linux/jbd.h:404): No description found for parameter 'h_lockdep_map'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-15 17:56:36 -07:00
Linus Torvalds
541010e4b8 Merge branch 'locks' of git://linux-nfs.org/~bfields/linux
* 'locks' of git://linux-nfs.org/~bfields/linux:
  nfsd: remove IS_ISMNDLCK macro
  Rework /proc/locks via seq_files and seq_list helpers
  fs/locks.c: use list_for_each_entry() instead of list_for_each()
  NFS: clean up explicit check for mandatory locks
  AFS: clean up explicit check for mandatory locks
  9PFS: clean up explicit check for mandatory locks
  GFS2: clean up explicit check for mandatory locks
  Cleanup macros for distinguishing mandatory locks
  Documentation: move locks.txt in filesystems/
  locks: add warning about mandatory locking races
  Documentation: move mandatory locking documentation to filesystems/
  locks: Fix potential OOPS in generic_setlease()
  Use list_first_entry in locks_wake_up_blocks
  locks: fix flock_lock_file() comment
  Memory shortage can result in inconsistent flocks state
  locks: kill redundant local variable
  locks: reverse order of posix_locks_conflict() arguments
2007-10-15 16:07:40 -07:00
Linus Torvalds
f4921aff5b Merge git://git.linux-nfs.org/pub/linux/nfs-2.6
* git://git.linux-nfs.org/pub/linux/nfs-2.6: (131 commits)
  NFSv4: Fix a typo in nfs_inode_reclaim_delegation
  NFS: Add a boot parameter to disable 64 bit inode numbers
  NFS: nfs_refresh_inode should clear cache_validity flags on success
  NFS: Fix a connectathon regression in NFSv3 and NFSv4
  NFS: Use nfs_refresh_inode() in ops that aren't expected to change the inode
  SUNRPC: Don't call xprt_release in call refresh
  SUNRPC: Don't call xprt_release() if call_allocate fails
  SUNRPC: Fix buggy UDP transmission
  [23/37] Clean up duplicate includes in
  [2.6 patch] net/sunrpc/rpcb_clnt.c: make struct rpcb_program static
  SUNRPC: Use correct type in buffer length calculations
  SUNRPC: Fix default hostname created in rpc_create()
  nfs: add server port to rpc_pipe info file
  NFS: Get rid of some obsolete macros
  NFS: Simplify filehandle revalidation
  NFS: Ensure that nfs_link() returns a hashed dentry
  NFS: Be strict about dentry revalidation when doing exclusive create
  NFS: Don't zap the readdir caches upon error
  NFS: Remove the redundant nfs_reval_fsid()
  NFSv3: Always use directory post-op attributes in nfs3_proc_lookup
  ...

Fix up trivial conflict due to sock_owned_by_user() cleanup manually in
net/sunrpc/xprtsock.c
2007-10-15 10:47:35 -07:00
Linus Torvalds
419217cb1d Merge branch 'v2.6.24-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep
* 'v2.6.24-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep:
  lockdep: annotate dir vs file i_mutex
  lockdep: per filesystem inode lock class
  lockdep: annotate kprobes irq fiddling
  lockdep: annotate rcu_read_{,un}lock{,_bh}
  lockdep: annotate journal_start()
  lockdep: s390: connect the sysexit hook
  lockdep: x86_64: connect the sysexit hook
  lockdep: i386: connect the sysexit hook
  lockdep: syscall exit check
  lockdep: fixup mutex annotations
  lockdep: fix mismatched lockdep_depth/curr_chain_hash
  lockdep: Avoid /proc/lockdep & lock_stat infinite output
  lockdep: maintainers
2007-10-15 10:40:41 -07:00
Linus Torvalds
b5869ce7f6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched: (140 commits)
  sched: sync wakeups preempt too
  sched: affine sync wakeups
  sched: guest CPU accounting: maintain guest state in KVM
  sched: guest CPU accounting: maintain stats in account_system_time()
  sched: guest CPU accounting: add guest-CPU /proc/<pid>/stat fields
  sched: guest CPU accounting: add guest-CPU /proc/stat field
  sched: domain sysctl fixes: add terminator comment
  sched: domain sysctl fixes: do not crash on allocation failure
  sched: domain sysctl fixes: unregister the sysctl table before domains
  sched: domain sysctl fixes: use for_each_online_cpu()
  sched: domain sysctl fixes: use kcalloc()
  Make scheduler debug file operations const
  sched: enable wake-idle on CONFIG_SCHED_MC=y
  sched: reintroduce topology.h tunings
  sched: allow the immediate migration of cache-cold tasks
  sched: debug, improve migration statistics
  sched: debug: increase width of debug line
  sched: activate task_hot() only on fair-scheduled tasks
  sched: reintroduce cache-hot affinity
  sched: speed up context-switches a bit
  ...
2007-10-15 08:22:16 -07:00
Linus Torvalds
37ca506adc Merge branch 'nfs-server-stable' of git://linux-nfs.org/~bfields/linux
* 'nfs-server-stable' of git://linux-nfs.org/~bfields/linux:
  knfsd: query filesystem for NFSv4 getattr of FATTR4_MAXNAME
  knfsd: nfsv4 delegation recall should take reference on client
  knfsd: don't shutdown callbacks until nfsv4 client is freed
  knfsd: let nfsd manage timing out its own leases
  knfsd: Add source address to sunrpc svc errors
  knfsd: 64 bit ino support for NFS server
  svcgss: move init code into separate function
  knfsd: remove code duplication in nfsd4_setclientid()
  nfsd warning fix
  knfsd: fix callback rpc cred
  knfsd: move nfsv4 slab creation/destruction to module init/exit
  knfsd: spawn kernel thread to probe callback channel
  knfsd: nfs4 name->id mapping not correctly parsing negative downcall
  knfsd: demote some printk()s to dprintk()s
  knfsd: cleanup of nfsd4 cmp_* functions
  knfsd: delete code made redundant by map_new_errors
  nfsd: fix horrible indentation in nfsd_setattr
  nfsd: remove unused cache_for_each macro
  nfsd: tone down inaccurate dprintk
2007-10-15 08:16:53 -07:00