kmemtrace now uses tracepoints instead of markers. We no longer need to
use format specifiers to pass arguments.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
[ folded: Use the new TP_PROTO and TP_ARGS to fix the build. ]
[ folded: fix build when CONFIG_KMEMTRACE is disabled. ]
[ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
linux/percpu.h includes linux/slab.h, which generates circular inclusion
dependencies when trying to switch kmemtrace to use tracepoints instead
of markers.
This patch allows tracing within slab headers' inline functions.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We want to remove percpu.h from rcupreempt.h, but if we do that
the percpu primitives there wont build anymore. Move them to the
.c file instead.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix for all non-x86 architectures
We want to remove percpu.h from rcuclassic.h/rcutree.h (for upcoming
kmemtrace changes) but that would break the DECLARE_PER_CPU based
declarations in these files.
Move the quiescent counter management functions to their respective
RCU implementation .c files - they were slightly above the inlining
limit anyway.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We want to remove percpu.h from rcupdate.h (for upcoming kmemtrace
changes), but this is not possible currently without breaking the
build because key.h has an implicit include file dependency on
rwsem.h:
CC [M] fs/cifs/cifs_spnego.o
In file included from include/keys/user-type.h:15,
from fs/cifs/cifs_spnego.c:24:
include/linux/key.h:128: error: field ‘sem’ has incomplete type
make[2]: *** [fs/cifs/cifs_spnego.o] Error 1
make[1]: *** [fs/cifs] Error 2
make: *** [fs] Error 2
Fix it by making the dependency explicit.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237884886.25315.39.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We want to remove percpu.h from rcupdate.h (for upcoming kmemtrace
changes), but this is not possible currently without breaking the
build because fdtable.h has an implicit include file dependency: it
uses __init does not include init.h.
This can cause build failures on non-x86 architectures:
/home/mingo/tip/include/linux/fdtable.h:66: error: expected '=', ',',
';', 'asm' or '__attribute__' before 'files_defer_init'
make[2]: *** [fs/locks.o] Error 1
We got this header included indirectly via rcupdate.h's percpu.h
inclusion - but if that is not there the build will break.
Fix it.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We want to remove percpu.h from rcupdate.h (for upcoming kmemtrace
changes), but this is not possible currently without breaking the
build because fs.h has an implicit include file depedency: it
uses PAGE_SIZE but does not include asm/page.h which defines it.
This problem gets masked in practice because most fs.h using sites
use rcupreempt.h (and other headers) which includes percpu.h which
brings in asm/page.h indirectly.
We cannot add asm/page.h to asm/fs.h because page.h is not an
exported header.
Move simple_transaction_set() to the other simple-transaction
file helpers in fs/libfs.c.
This removes the include file hell and also reduces
kernel size a bit.
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We want to remove percpu.h from rcupdate.h (for upcoming kmemtrace
changes), but this is not possible currently without breaking the
build because fs.h has implicit include file depedencies: it uses
GFP_* types in inlines but does not include gfp.h.
In practice most fs.h using .c files get gfp.h included implicitly,
via an indirect route: via rcupdate.h inclusion - so this underlying
problem gets masked in practice.
So we want to solve fs.h's dependency on gfp.h.
gfp.h can not be included here directly because it is not exported and it
would break the build the following way:
/home/mingo/tip/usr/include/linux/bsg.h:11: found __[us]{8,16,32,64} type without #include <linux/types.h>
/home/mingo/tip/usr/include/linux/fs.h:11: included file 'linux/gfp.h' is not exported
make[3]: *** [/home/mingo/tip/usr/include/linux/.check] Error 1
make[2]: *** [linux] Error 2
As suggested by Alexey Dobriyan, move alloc_secdata() and free_secdata()
to linux/security.h - they belong there. This also cleans fs.h of GFP_*
usage.
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237906803.25315.96.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Today's linux-next build (powerpc ppc64_defconfig) failed like this:
In file included from net/core/skbuff.c:69:
include/trace/skb.h:4: error: expected ')' before '(' token
include/trace/skb.h:4: error: expected ')' before '(' token
[...]
Caused by commit 2939b0469d ("tracing:
replace TP<var> with TP_<var>") from the tracing tree interacting with
commit 4893d39e86 ("Network Drop Monitor:
Add trace declaration for skb frees") from the net tree.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (58 commits)
SUNRPC: Ensure IPV6_V6ONLY is set on the socket before binding to a port
NSM: Fix unaligned accesses in nsm_init_private()
NFS: Simplify logic to compare socket addresses in client.c
NFS: Start PF_INET6 callback listener only if IPv6 support is available
lockd: Start PF_INET6 listener only if IPv6 support is available
SUNRPC: Remove CONFIG_SUNRPC_REGISTER_V4
SUNRPC: rpcb_register() should handle errors silently
SUNRPC: Simplify kernel RPC service registration
SUNRPC: Simplify svc_unregister()
SUNRPC: Allow callers to pass rpcb_v4_register a NULL address
SUNRPC: rpcbind actually interprets r_owner string
SUNRPC: Clean up address type casts in rpcb_v4_register()
SUNRPC: Don't return EPROTONOSUPPORT in svc_register()'s helpers
SUNRPC: Use IPv4 loopback for registering AF_INET6 kernel RPC services
SUNRPC: Set IPV6ONLY flag on PF_INET6 RPC listener sockets
NFS: Revert creation of IPv6 listeners for lockd and NFSv4 callbacks
SUNRPC: Remove @family argument from svc_create() and svc_create_pooled()
SUNRPC: Change svc_create_xprt() to take a @family argument
SUNRPC: svc_setup_socket() gets protocol family from socket
SUNRPC: Pass a family argument to svc_register()
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (33 commits)
ext4: Regularize mount options
ext4: fix locking typo in mballoc which could cause soft lockup hangs
ext4: fix typo which causes a memory leak on error path
jbd2: Update locking coments
ext4: Rename pa_linear to pa_type
ext4: add checks of block references for non-extent inodes
ext4: Check for an valid i_mode when reading the inode from disk
ext4: Use WRITE_SYNC for commits which are caused by fsync()
ext4: Add auto_da_alloc mount option
ext4: Use struct flex_groups to calculate get_orlov_stats()
ext4: Use atomic_t's in struct flex_groups
ext4: remove /proc tuning knobs
ext4: Add sysfs support
ext4: Track lifetime disk writes
ext4: Fix discard of inode prealloc space with delayed allocation.
ext4: Automatically allocate delay allocated blocks on rename
ext4: Automatically allocate delay allocated blocks on close
ext4: add EXT4_IOC_ALLOC_DA_BLKS ioctl
ext4: Simplify delalloc code by removing mpage_da_writepages()
ext4: Save stack space by removing fake buffer heads
...
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (59 commits)
ide-floppy: do not complete rq's prematurely
ide: be able to build pmac driver without IDE built-in
ide-pmac: IDE cable detection on Apple PowerBook
ide: inline SELECT_DRIVE()
ide: turn selectproc() method into dev_select() method (take 5)
MAINTAINERS: move old ide-{floppy,tape} entries to CREDITS (take 2)
ide: move data register access out of tf_{read|load}() methods (take 2)
ide: call {in|out}put_data() methods from tf_{read|load}() methods (take 2)
ide-io-std: shorten ide_{in|out}put_data()
ide: rename IDE_TFLAG_IN_[HOB_]FEATURE
ide: turn set_irq() method into write_devctl() method
ide: use ATA_HOB
ide-disk: use ATA_ERR
ide: add support for CFA specified transfer modes (take 3)
ide-iops: only clear DMA words on setting DMA mode
ide: identify data word 53 bit 1 doesn't cover words 62 and 63 (take 3)
au1xxx-ide: auide_{in|out}sw() should be static
ide-floppy: use ide_pio_bytes()
ide-{floppy,tape}: fix padding for PIO transfers
ide: remove CONFIG_BLK_DEV_IDEDOUBLER config option
...
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (88 commits)
PCI: fix HT MSI mapping fix
PCI: don't enable too much HT MSI mapping
x86/PCI: make pci=lastbus=255 work when acpi is on
PCI: save and restore PCIe 2.0 registers
PCI: update fakephp for bus_id removal
PCI: fix kernel oops on bridge removal
PCI: fix conflict between SR-IOV and config space sizing
powerpc/PCI: include pci.h in powerpc MSI implementation
PCI Hotplug: schedule fakephp for feature removal
PCI Hotplug: rename legacy_fakephp to fakephp
PCI Hotplug: restore fakephp interface with complete reimplementation
PCI: Introduce /sys/bus/pci/devices/.../rescan
PCI: Introduce /sys/bus/pci/devices/.../remove
PCI: Introduce /sys/bus/pci/rescan
PCI: Introduce pci_rescan_bus()
PCI: do not enable bridges more than once
PCI: do not initialize bridges more than once
PCI: always scan child buses
PCI: pci_scan_slot() returns newly found devices
PCI: don't scan existing devices
...
Fix trivial append-only conflict in Documentation/feature-removal-schedule.txt
The s1d13xxx chip provides two values of identification value: the
Production id (e.g 13506/13505/13806..) and a revision number 0,1,2,3).
Together these can help us to differentiate between similiar setups.
This patch adds the proper way of grabbing both those values and save them
for future reference (in order to decide what functions a card supports,
e.g acceleration).
We also move away from the concept of all s1d13xxx = s1d13806 when we
really support alot more.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: simplify s1d13xxxfb_probe()]
Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With a postfix decrement t reaches -1 on timeout which results in a
return of 0.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an accelerator constant so almost all Cirrus are recognized as
accelerators by the fbset command.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix 8bpp mode by adding handling of the Laguna chipsets to various places
and stop trashing a HDR register which probably does not exist on the
Laguna.
Fix compilation warnings about uninitialized variables also.
Finally, all 8bpp, 16bpp and 32bpp modes work on the Laguna chipset.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add additional overflow register setting for Laguna chips.
Also, simplify some code in the cirrusfb_pan_display() and
cirrusfb_blank().
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
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>
Fix trailing whitespace because quilt complained about it.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- the LEAP_YEAR macro is buggy - it references its arg multiple times.
Fix this by turning it into a C function.
- give it a more approriate name
- Move it to rtc.h so that other .c files can use it, instead of copying it.
Cc: dann frazier <dannf@hp.com>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: stephane eranian <eranian@googlemail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
autofs_dev-ioctl.h is included by both the kernel module and user space tools
and it includes two kernel header files. Compiles work if the kernel headers
are installed but fail otherwise.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement full support for OF SPI bindings. Now the driver can manage its
own chip selects without any help from the board files and/or fsl_soc
constructors.
The "legacy" code is well isolated and could be removed as time goes by.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The main purpose of this patch is to pass 'struct spi_device' to the chip
select handling routines. This is needed so that we could implement
full-fledged OpenFirmware support for this driver.
While at it, also:
- Replace two {de,activate}_cs routines by single cs_contol().
- Don't duplicate platform data callbacks in mpc83xx_spi struct.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce new wakeup macros that allow passing an event mask to the wakeup
targets. They exactly mimic their non-_poll() counterpart, with the added
event mask passing capability. I did add only the ones currently
requested, avoiding the _nr() and _all() for the moment.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: William Lee Irwin III <wli@movementarian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset introduces wakeup hints for some of the most popular (from
epoll POV) devices, so that epoll code can avoid spurious wakeups on its
waiters.
The problem with epoll is that the callback-based wakeups do not, ATM,
carry any information about the events the wakeup is related to. So the
only choice epoll has (not being able to call f_op->poll() from inside the
callback), is to add the file* to a ready-list and resolve the real events
later on, at epoll_wait() (or its own f_op->poll()) time. This can cause
spurious wakeups, since the wake_up() itself might be for an event the
caller is not interested into.
The rate of these spurious wakeup can be pretty high in case of many
network sockets being monitored.
By allowing devices to report the events the wakeups refer to (at least
the two major classes - POLLIN/POLLOUT), we are able to spare useless
wakeups by proper handling inside the epoll's poll callback.
Epoll will have in any case to call f_op->poll() on the file* later on,
since the change to be done in order to have the full event set sent via
wakeup, is too invasive for the way our f_op->poll() system works (the
full event set is calculated inside the poll function - there are too many
of them to even start thinking the change - also poll/select would need
change too).
Epoll is changed in a way that both devices which send event hints, and
the ones that don't, are correctly handled. The former will gain some
efficiency though.
As a general rule for devices, would be to add an event mask by using
key-aware wakeup macros, when making up poll wait queues. I tested it
(together with the epoll's poll fix patch Andrew has in -mm) and wakeups
for the supported devices are correctly filtered.
Test program available here:
http://www.xmailserver.org/epoll_test.c
This patch:
Nothing revolutionary here. Just using the available "key" that our
wakeup core already support. The __wake_up_locked_key() was no brainer,
since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers
around __wake_up_common().
The __wake_up_sync() function had a body, so the choice was between
borrowing the body for __wake_up_sync_key() and calling it from
__wake_up_sync(), or make an inline and calling it from both. I chose the
former since in most archs it all resolves to "mov $0, REG; jmp ADDR".
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: William Lee Irwin III <wli@movementarian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
People started using eventfd in a semaphore-like way where before they
were using pipes.
That is, counter-based resource access. Where a "wait()" returns
immediately by decrementing the counter by one, if counter is greater than
zero. Otherwise will wait. And where a "post(count)" will add count to
the counter releasing the appropriate amount of waiters. If eventfd the
"post" (write) part is fine, while the "wait" (read) does not dequeue 1,
but the whole counter value.
The problem with eventfd is that a read() on the fd returns and wipes the
whole counter, making the use of it as semaphore a little bit more
cumbersome. You can do a read() followed by a write() of COUNTER-1, but
IMO it's pretty easy and cheap to make this work w/out extra steps. This
patch introduces a new eventfd flag that tells eventfd to only dequeue 1
from the counter, allowing simple read/write to make it behave like a
semaphore. Simple test here:
http://www.xmailserver.org/eventfd-sem.c
To be back-compatible with earlier kernels, userspace applications should
probe for the availability of this feature via
#ifdef EFD_SEMAPHORE
fd = eventfd2 (CNT, EFD_SEMAPHORE);
if (fd == -1 && errno == EINVAL)
<fallback>
#else
<fallback>
#endif
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: <linux-api@vger.kernel.org>
Tested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We cover all log-levels by pr_... macros except KERN_CONT one. Add it
for convenience.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the filesystem freeze operation has been elevated to the VFS, and
is just an ioctl away, some sort of safety net for unintentionally frozen
root filesystems may be in order.
The timeout thaw originally proposed did not get merged, but perhaps
something like this would be useful in emergencies.
For example, freeze /path/to/mountpoint may freeze your root filesystem if
you forgot that you had that unmounted.
I chose 'j' as the last remaining character other than 'h' which is sort
of reserved for help (because help is generated on any unknown character).
I've tested this on a non-root fs with multiple (nested) freezers, as well
as on a system rendered unresponsive due to a frozen root fs.
[randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the following header file changes:
- remove arch ifdefs and asm/suspend.h from linux/suspend.h
- add asm/suspend.h to disk.c (for arch_prepare_suspend())
- add linux/io.h to swsusp.c (for ioremap())
- x86 32/64 bit compile fixes
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Synopsis: if shmem_writepage calls swap_writepage directly, most shmem
swap loads benefit, and a catastrophic interaction between SLUB and some
flash storage is avoided.
shmem_writepage() has always been peculiar in making no attempt to write:
it has just transferred a shmem page from file cache to swap cache, then
let that page make its way around the LRU again before being written and
freed.
The idea was that people use tmpfs because they want those pages to stay
in RAM; so although we give it an overflow to swap, we should resist
writing too soon, giving those pages a second chance before they can be
reclaimed.
That was always questionable, and I've toyed with this patch for years;
but never had a clear justification to depart from the original design.
It became more questionable in 2.6.28, when the split LRU patches classed
shmem and tmpfs pages as SwapBacked rather than as file_cache: that in
itself gives them more resistance to reclaim than normal file pages. I
prepared this patch for 2.6.29, but the merge window arrived before I'd
completed gathering statistics to justify sending it in.
Then while comparing SLQB against SLUB, running SLUB on a laptop I'd
habitually used with SLAB, I found SLUB to run my tmpfs kbuild swapping
tests five times slower than SLAB or SLQB - other machines slower too, but
nowhere near so bad. Simpler "cp -a" swapping tests showed the same.
slub_max_order=0 brings sanity to all, but heavy swapping is too far from
normal to justify such a tuning. The crucial factor on that laptop turns
out to be that I'm using an SD card for swap. What happens is this:
By default, SLUB uses order-2 pages for shmem_inode_cache (and many other
fs inodes), so creating tmpfs files under memory pressure brings lumpy
reclaim into play. One subpage of the order is chosen from the bottom of
the LRU as usual, then the other three picked out from their random
positions on the LRUs.
In a tmpfs load, many of these pages will be ones which already passed
through shmem_writepage, so already have swap allocated. And though their
offsets on swap were probably allocated sequentially, now that the pages
are picked off at random, their swap offsets are scattered.
But the flash storage on the SD card is very sensitive to having its
writes merged: once swap is written at scattered offsets, performance
falls apart. Rotating disk seeks increase too, but less disastrously.
So: stop giving shmem/tmpfs pages a second pass around the LRU, write them
out to swap as soon as their swap has been allocated.
It's surely possible to devise an artificial load which runs faster the
old way, one whose sizing is such that the tmpfs pages on their second
pass are the ones that are wanted again, and other pages not.
But I've not yet found such a load: on all machines, under the loads I've
tried, immediate swap_writepage speeds up shmem swapping: especially when
using the SLUB allocator (and more effectively than slub_max_order=0), but
also with the others; and it also reduces the variance between runs. How
much faster varies widely: a factor of five is rare, 5% is common.
One load which might have suffered: imagine a swapping shmem load in a
limited mem_cgroup on a machine with plenty of memory. Before 2.6.29 the
swapcache was not charged, and such a load would have run quickest with
the shmem swapcache never written to swap. But now swapcache is charged,
so even this load benefits from shmem_writepage directly to swap.
Apologies for the #ifndef CONFIG_SWAP swap_writepage() stub in swap.h:
it's silly because that will never get called; but refactoring shmem.c
sensibly according to CONFIG_SWAP will be a separate task.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
try_to_free_pages() is used for the direct reclaim of up to
SWAP_CLUSTER_MAX pages when watermarks are low. The caller to
alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to
be used but this is not passed to try_to_free_pages(). This can lead to
unnecessary reclaim of pages that are unusable by the caller and int the
worst case lead to allocation failure as progress was not been make where
it is needed.
This patch passes the nodemask used for alloc_pages_nodemask() to
try_to_free_pages().
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mlock() facility does not exist for NOMMU since all mappings are
effectively locked anyway, so we don't make the bits available when
they're not useful.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use debug_kmap_atomic in kmap_atomic, kmap_atomic_pfn, and
iomap_atomic_prot_pfn.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86 has debug_kmap_atomic_prot() which is error checking function for
kmap_atomic. It is usefull for the other architectures, although it needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.
This patch exposes it to the other architectures.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags. There should be no functional change.
This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg. virtual_address to the
driver, which might be important in some special cases).
This is required for a subsequent fix. And will also make it easier to
merge page_mkwrite() with fault() in future.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On PowerPC we allocate large boot time hashes on node 0. This leads to an
imbalance in the free memory, for example on a 64GB box (4 x 16GB nodes):
Free memory:
Node 0: 97.03%
Node 1: 98.54%
Node 2: 98.42%
Node 3: 98.53%
If we switch to using vmalloc (like ia64 and x86-64) things are more
balanced:
Free memory:
Node 0: 97.53%
Node 1: 98.35%
Node 2: 98.33%
Node 3: 98.33%
For many HPC applications we are limited by the free available memory on
the smallest node, so even though the same amount of memory is used the
better balancing helps.
Since all 64bit NUMA capable architectures should have sufficient vmalloc
space, it makes sense to enable it via CONFIG_64BIT.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9838
On i386, HZ=1000, jiffies_to_clock_t() converts time in a somewhat strange
way from the user's point of view:
# echo 500 >/proc/sys/vm/dirty_writeback_centisecs
# cat /proc/sys/vm/dirty_writeback_centisecs
499
So, we have 5000 jiffies converted to only 499 clock ticks and reported
back.
TICK_NSEC = 999848
ACTHZ = 256039
Keeping in-kernel variable in units passed from userspace will fix issue
of course, but this probably won't be right for every sysctl.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.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>
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390. This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().
This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I notice there are many places doing copy_from_user() which follows
kmalloc():
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return -ENOMEM;
if (copy_from_user(dst, src, len)) {
kfree(dst);
return -EFAULT
}
memdup_user() is a wrapper of the above code. With this new function, we
don't have to write 'len' twice, which can lead to typos/mistakes. It
also produces smaller code and kernel text.
A quick grep shows 250+ places where memdup_user() *may* be used. I'll
prepare a patchset to do this conversion.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a helper function account_page_dirtied(). Use that from two
callsites. reiser4 adds a function which adds a third callsite.
Signed-off-by: Edward Shishkin<edward.shishkin@gmail.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>
Impact: cleanup
In almost cases, for_each_zone() is used with populated_zone(). It's
because almost function doesn't need memoryless node information.
Therefore, for_each_populated_zone() can help to make code simplify.
This patch has no functional change.
[akpm@linux-foundation.org: small cleanup]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct tty_operations::proc_fops took it's place and there is one less
create_proc_read_entry() user now!
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Used for gradual switch of TTY drivers from using ->read_proc which helps
with gradual switch from ->read_proc for the whole tree.
As side effect, fix possible race condition when ->data initialized after
PDE is hooked into proc tree.
->proc_fops takes precedence over ->read_proc.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
