The pipe may be driving various bpp values depending on the display
configuration, so take that into account when calculating link bandwidth
requirements.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
Updating the planes is device specific, so create a new display callback
and use it in pipe_set_base. (In fact we could go even further, valid
display plane bits have changed with each generation, as has tiled
buffer handling.)
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
Figuring out which pipe bpp to use is a bit painful. It depends on both
the encoder and display configuration attached to a pipe. For instance,
to drive a 24bpp framebuffer out to an 18bpp panel, we need to use 6bpc
on the pipe but also enable dithering. But driving that same
framebuffer to a DisplayPort output on another pipe means using 8bpc and
no dithering.
So split out and enhance the code to handle the various cases, returning
an appropriate pipe bpp as well as whether dithering should be enabled.
Save the resulting pipe bpp in the intel_crtc struct for use by encoders
in calculating bandwidth requirements (defaults to 24bpp on pre-ILK).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
This may not be the default value, so pull the bpc out of the pipe reg
and write it to the DP transcoder so proper dithering and signaling
occurs.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
This prevents us from setting reserved or incorrect bits on CougarPoint.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
These bits are reserved on ILK+ (ILK+ provides this feature in the
transcoder and pipe configuration instead, which we already set).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
In an attempt to fix 38862 and 38863.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
This lets us make the various IRQ functions static and helps avoid
problems like the one fixed in "drm/i915: Use chipset-specific irq
installers" where one of the exported functions was called rather than
the chipset specific version.
This also fixes a UMS-mode bug -- the correct irq functions for IRL
and later chips were only getting loaded in the KMS path.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
As pointed out by Dan Carpenter, it was seemingly possible to hit an error
whilst mapping the buffer for the regs (except the only likely error
returns should not happen during init) and so leak a pin count on the
bo. To handle this we would need to reacquire the struct mutex, so for
simplicity rearrange for the lock to be held for the entire function.
For extra pedagogy, test that we only call init once.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
They use the same register interfaces, so we can simply enable the
existing code on IVB.
v2:
- resolve conflict with ring freq scaling, we can enable it too
v3:
- resolve conflict again, this time on drm-intel-next
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
Reported-by: Pavel Roskin <proski@gnu.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38777
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
Lots of register access in these functions, some of which requires the
struct mutex.
These functions now hold the struct mutex across the calls to
i915_save_display and i915_restore_display, and so the internal mutex
calls in those functions have been removed. To ensure that no-one else
was calling them (and hence violating the new required locking
invarient), those functions have been made static.
gen6_enable_rps locks the struct mutex, and so i915_restore_state
unlocks the mutex around calls to that function.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
Provide a parameter to disable hanghcheck. This is useful mostly for
developers trying to debug known problems, and probably should not be
touched by normal users.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
The ring frequency scaling table tells the PCU to treat certain GPU
frequencies as if they were a given CPU frequency for purposes of
scaling the ring frequency. Normally the PCU will scale the ring
frequency based on the CPU P-state, but with the table present, it will
also take the GPU frequency into account.
The main downside of keeping the ring frequency high while the CPU is
at a low frequency (or asleep altogether) is increased power
consumption. But then if you're keeping your GPU busy, you probably
want the extra performance.
v2:
- add units to debug table header (from Eric)
- use tsc_khz as a fallback if the cpufreq driver doesn't give us a freq
(from Chris)
v3:
- fix comments & debug output
- remove unneeded force wake get/put
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
This allows drivers and other code to get the max reported CPU frequency.
Initial use is for scaling ring frequency with GPU frequency in the i915
driver.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
* 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
Connector: Correctly set the error code in case of success when dispatching receive callbacks
Connector: Set the CN_NETLINK_USERS correctly
pti: PTI semantics fix in pti_tty_cleanup.
pti: ENXIO error case memory leak PTI fix.
pti: double-free security PTI fix
drivers:misc: ti-st: fix skipping of change remote baud
drivers/base/platform.c: don't mark platform_device_register_resndata() as __init_or_module
st_kim: Handle case of no device found for ID 0
firmware: fix GOOGLE_SMI kconfig dependency warning
* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
MAINTAINERS: add myself as maintainer of USB/IP
usb: r8a66597-hcd: fix cannot detect low/full speed device
USB: ehci-ath79: fix a NULL pointer dereference
USB: Add new FT232H chip to drivers/usb/serial/ftdi_sio.c
usb/isp1760: Fix bug preventing the unlinking of control urbs
USB: Fix up URB error codes to reflect implementation.
xhci: Always set urb->status to zero for isoc endpoints.
xhci: Add reset on resume quirk for asrock p67 host
xHCI 1.0: Incompatible Device Error
USB: don't let errors prevent system sleep
USB: don't let the hub driver prevent system sleep
USB: change maintainership of ohci-hcd and ehci-hcd
xHCI 1.0: Force Stopped Event(FSE)
xhci: Don't warn about zeroed bMaxBurst descriptor field.
USB: Free bandwidth when usb_disable_device is called.
xhci: Reject double add of active endpoints.
USB: TI 3410/5052 USB Serial Driver: Fix mem leak when firmware is too big.
usb: musb: gadget: clear TXPKTRDY flag when set FLUSHFIFO
usb: musb: host: compare status for negative error values
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
serial: bcm63xx_uart: fix irq storm after rx fifo overrun.
amba pl011: platform data for reg lockup and glitch v2
amba pl011: workaround for uart registers lockup
tty: n_gsm: improper skb_pull() use was leaking framed data
tty: n_gsm: Fixed logic to decode break signal from modem status
TTY: ntty, add one more sanity check
TTY: ldisc, do not close until there are readers
8250: Fix capabilities when changing the port type
8250_pci: Fix missing const from merges
ARM: SAMSUNG: serial: Fix on handling of one clock source for UART
serial: ioremap warning fix for jsm driver.
8250_pci: add -ENODEV code for Intel EG20T PCH
* 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
Staging: comedi: fix build breakages on some platforms
Staging: brcm80211: disable drivers except for X86 or MIPS platforms
Staging: brcm80211: disable drivers for PPC platforms
Staging: iio: Make IIO depend on GENERIC_HARDIRQS
Staging: mei: fix suspend failure
Staging: fix iio builds when IIO_RING_BUFFER is not enabled
Staging: Comedi: Build only on arches providing PAGE_KERNEL_NOCACHE
Staging: fix more iio builds when IIO_RING_BUFFER is not enabled
Konstantin Belousov pointed out that 4697995b98 replaced the generic
i915_driver_irq_*install() functions with chipset specific routines
accessible only through driver->irq_*install(). So update the sanity
check in i915_request_wait() to match.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
The failure is as follows:
1. Userspace gets forcewake lock, lock count >=1
2. GPU hang/reset occurs (forcewake bit is reset)
3. count is now incorrect
The failure can only occur when using the forcewake userspace lock.
This has the unfortunate consequence of messing up the driver as well as
userspace, unless userspace closes the debugfs file, the kernel will
never end up waking the GT since the refcount will be > 1.
The solution is to try to recover the correct forcewake state based on
the refcount. There is a period of time where userspace reads/writes may
occur after the reset, before the GT has been forcewaked. The interface
was never designed to be a perfect solution for userspace reads/writes,
and the kernel portion is fixed by this patch.
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
/proc/PID/io may be used for gathering private information. E.g. for
openssh and vsftpd daemons wchars/rchars may be used to learn the
precise password length. Restrict it to processes being able to ptrace
the target process.
ptrace_may_access() is needed to prevent keeping open file descriptor of
"io" file, executing setuid binary and gathering io information of the
setuid'ed process.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.
We should check if the device is faulty before considering it to be a
spare. This will avoid trying to start a recovery that cannot
proceed.
This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.
Cc: stable@kernel.org
Reported-by: Jim Paradis <james.paradis@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
When auditing the locking in i915_gem.c (for a prospective change which
I then abandoned), I noticed two places where struct_mutex is not held
across GEM object manipulations that would usually require it.
Since one is in initial setup and the other in driver unload, I'm
guessing the mutex is not required for either; but post a patch in case
it is.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The interface to ->truncate_range is changing very slightly: once "tmpfs:
take control of its truncate_range" has been applied, this can be applied.
For now there is only a slight inefficiency while this remains unapplied,
but it will soon become essential for managing shmem's use of swap.
Change i915_gem_object_truncate() to use shmem_truncate_range() directly:
which should also spare i915 later change if we switch from
inode_operations->truncate_range to file_operations->fallocate.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Soon tmpfs will stop supporting ->readpage and read_cache_page_gfp(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.
Make i915_gem_object_get_pages_gtt() use shmem_read_mapping_page_gfp() in
the one place it's needed; elsewhere use shmem_read_mapping_page(), with
the mapping's gfp_mask properly initialized.
Forget about __GFP_COLD: since tmpfs initializes its pages with memset,
asking for a cold page is counter-productive.
Include linux/shmem_fs.h also in drm_gem.c: with shmem_file_setup() now
declared there too, we shall remove the prototype from linux/mm.h later.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Soon tmpfs will stop supporting ->readpage and read_mapping_page(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.
ttm_tt_swapin() and ttm_tt_swapout() use shmem_read_mapping_page() in
place of read_mapping_page(), since their swap_space has been created with
shmem_file_setup().
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix this section mismatch:
WARNING: drivers/misc/ioc4.o(.data+0x144): Section mismatch in reference from the variable ioc4_load_modules_work to the function .devinit.text:ioc4_load_modules()
The variable ioc4_load_modules_work references
the function __devinit ioc4_load_modules()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
This one is potentially fatal; by the time ioc4_load_modules is invoked
it may already have been freed. For that reason ioc4_load_modules_work
can't be turned to __devinitdata but also because it's referenced in
ioc4_exit.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Brent Casavant <bcasavan@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix this section mismatch:
WARNING: drivers/leds/leds-lp5523.o(.text+0x12f4): Section mismatch in reference from the function lp5523_probe() to the function .init.text:lp5523_init_led()
The function lp5523_probe() references
the function __init lp5523_init_led().
This is often because lp5523_probe lacks a __init
annotation or the annotation of lp5523_init_led is wrong.
Fixing this one triggers one more mismatch, fix that one as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix this section mismatch:
WARNING: drivers/leds/leds-lp5521.o(.text+0xf2c): Section mismatch in reference from the function lp5521_probe() to the function .init.text:lp5521_init_led()
The function lp5521_probe() references
the function __init lp5521_init_led().
This is often because lp5521_probe lacks a __init
annotation or the annotation of lp5521_init_led is wrong.
Fixing this mismatch triggers one more mismatch, fix that one as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit d149e3b25d ("memcg: add the soft_limit reclaim in global direct
reclaim") adds a softlimit hook to shrink_zones(). By this, soft limit
is called as
try_to_free_pages()
do_try_to_free_pages()
shrink_zones()
mem_cgroup_soft_limit_reclaim()
Then, direct reclaim is memcg softlimit hint aware, now.
But, the memory cgroup's "limit" path can call softlimit shrinker.
try_to_free_mem_cgroup_pages()
do_try_to_free_pages()
shrink_zones()
mem_cgroup_soft_limit_reclaim()
This will cause a global reclaim when a memcg hits limit.
This is bug. soft_limit_reclaim() should be called when
scanning_global_lru(sc) == true.
And the commit adds a variable "total_scanned" for counting softlimit
scanned pages....it's not "total". This patch removes the variable and
update sc->nr_scanned instead of it. This will affect shrink_slab()'s
scan condition but, global LRU is scanned by softlimit and I think this
change makes sense.
TODO: avoid too much scanning of a zone when softlimit did enough work.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Ying Han <yinghan@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a single process may register exit handlers unlimited times.
It may lead to a bloated listeners chain and very slow process
terminations.
Eg after 10KK sent TASKSTATS_CMD_ATTR_REGISTER_CPUMASKs ~300 Mb of
kernel memory is stolen for the handlers chain and "time id" shows 2-7
seconds instead of normal 0.003. It makes it possible to exhaust all
kernel memory and to eat much of CPU time by triggerring numerous exits
on a single CPU.
The patch limits the number of times a single process may register
itself on a single CPU to one.
One little issue is kept unfixed - as taskstats_exit() is called before
exit_files() in do_exit(), the orphaned listener entry (if it was not
explicitly deregistered) is kept until the next someone's exit() and
implicit deregistration in send_cpu_listeners(). So, if a process
registered itself as a listener exits and the next spawned process gets
the same pid, it would inherit taskstats attributes.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Under heavy memory and filesystem load, users observe the assertion
mapping->nrpages == 0 in end_writeback() trigger. This can be caused by
page reclaim reclaiming the last page from a mapping in the following
race:
CPU0 CPU1
...
shrink_page_list()
__remove_mapping()
__delete_from_page_cache()
radix_tree_delete()
evict_inode()
truncate_inode_pages()
truncate_inode_pages_range()
pagevec_lookup() - finds nothing
end_writeback()
mapping->nrpages != 0 -> BUG
page->mapping = NULL
mapping->nrpages--
Fix the problem by doing a reliable check of mapping->nrpages under
mapping->tree_lock in end_writeback().
Analyzed by Jay <jinshan.xiong@whamcloud.com>, lost in LKML, and dug out
by Miklos Szeredi <mszeredi@suse.de>.
Cc: Jay <jinshan.xiong@whamcloud.com>
Cc: Miklos Szeredi <mszeredi@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We cannot take a mutex while holding a spinlock, so flip the order and
fix the locking documentation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We observed the crash point count going negative in cases where the
crash point is hit multiple times before the check of "count == 0" is
done. Because of this we never call lkdtm_do_action(). This patch just
adds a spinlock to protect count.
Reported-by: Tapan Dhimant <tdhimant@akamai.com>
Signed-off-by: Josh Hunt <johunt@akamai.com>
Acked-by: Ankita Garg <ankita@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is required for tilegx to be able to use the compat unistd.h header
where compat_sys_sendmmsg() is now mentioned.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
romfs_get_unmapped_area() checks argument `len' without considering
PAGE_ALIGN which will cause do_mmap_pgoff() return -EINVAL error after
commit f67d9b1576 ("nommu: add page_align to mmap").
Fix the check by changing it in same way ramfs_nommu_get_unmapped_area()
was changed in ramfs/file-nommu.c.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To make SLUB work on UML we need this_cpu_cmpxchg from
asm-generic/percpu.h.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PT7C4338 chip is being manufactured by Pericom Technology Inc. It is a
serial real-time clock which provides:
1) Low-power clock/calendar.
2) Programmable square-wave output.
It has 56 bytes of nonvolatile RAM. Its register set is same as that of
rtc device: DS1307.
Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Acked-by: Timur Tabi <timur@freescale.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although it is used (by i915) on nothing but tmpfs, read_cache_page_gfp()
is unsuited to tmpfs, because it inserts a page into pagecache before
calling the filesystem's ->readpage: tmpfs may have pages in swapcache
which only it knows how to locate and switch to filecache.
At present tmpfs provides a ->readpage method, and copes with this by
copying pages; but soon we can simplify it by removing its ->readpage.
Provide shmem_read_mapping_page_gfp() now, ready for that transition,
Export shmem_read_mapping_page_gfp() and add it to list in shmem_fs.h,
with shmem_read_mapping_page() inline for the common mapping_gfp case.
(shmem_read_mapping_page_gfp or shmem_read_cache_page_gfp? Generally the
read_mapping_page functions use the mapping's ->readpage, and the
read_cache_page functions use the supplied filler, so I think
read_cache_page_gfp was slightly misnamed.)
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.35's new truncate convention gave tmpfs the opportunity to control
its file truncation, no longer enforced from outside by vmtruncate().
We shall want to build upon that, to handle pagecache and swap together.
Slightly redefine the ->truncate_range interface: let it now be called
between the unmap_mapping_range()s, with the filesystem responsible for
doing the truncate_inode_pages_range() from it - just as the filesystem
is nowadays responsible for doing that from its ->setattr.
Let's rename shmem_notify_change() to shmem_setattr(). Instead of
calling the generic truncate_setsize(), bring that code in so we can
call shmem_truncate_range() - which will later be updated to perform its
own variant of truncate_inode_pages_range().
Remove the punch_hole unmap_mapping_range() from shmem_truncate_range():
now that the COW's unmap_mapping_range() comes after ->truncate_range,
there is no need to call it a third time.
Export shmem_truncate_range() and add it to the list in shmem_fs.h, so
that i915_gem_object_truncate() can call it explicitly in future; get
this patch in first, then update drm/i915 once this is available (until
then, i915 will just be doing the truncate_inode_pages() twice).
Though introduced five years ago, no other filesystem is implementing
->truncate_range, and its only other user is madvise(,,MADV_REMOVE): we
expect to convert it to fallocate(,FALLOC_FL_PUNCH_HOLE,,) shortly,
whereupon ->truncate_range can be removed from inode_operations -
shmem_truncate_range() will help i915 across that transition too.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
