Marek Vasut [Thu, 12 Aug 2010 01:14:54 +0000 (02:14 +0100)]
ARM: Fix gen_nand probe structures contents
These three platforms didn't properly fill nr_chips in gen_nand
registration and therefore depended on gen_nand bug fixed by commit 81cbb0b17796d81cbd92defe113cf2a7c7a21fbb ("mtd: gen_nand: fix support for
multiple chips")
Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Randy Dunlap [Tue, 25 May 2010 05:22:51 +0000 (22:22 -0700)]
mtd/nand_base: fix kernel-doc warnings & typos
Fix mtd/nand_base.c kernel-doc warnings and typos.
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Linus Torvalds [Tue, 10 Aug 2010 18:49:21 +0000 (11:49 -0700)]
Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6: (79 commits)
mtd: Remove obsolete <mtd/compatmac.h> include
mtd: Update copyright notices
jffs2: Update copyright notices
mtd-physmap: add support users can assign the probe type in board files
mtd: remove redwood map driver
mxc_nand: Add v3 (i.MX51) Support
mxc_nand: support 8bit ecc
mxc_nand: fix correct_data function
mxc_nand: add V1_V2 namespace to registers
mxc_nand: factor out a check_int function
mxc_nand: make some internally used functions overwriteable
mxc_nand: rework get_dev_status
mxc_nand: remove 0xe00 offset from registers
mtd: denali: Add multi connected NAND support
mtd: denali: Remove set_ecc_config function
mtd: denali: Remove unuseful code in get_xx_nand_para functions
mtd: denali: Remove device_info_tag structure
mtd: m25p80: add support for the Winbond W25Q32 SPI flash chip
mtd: m25p80: add support for the Intel/Numonyx {16,32,64}0S33B SPI flash chips
mtd: m25p80: add support for the EON EN25P{32, 64} SPI flash chips
...
Fix up trivial conflicts in drivers/mtd/maps/{Kconfig,redwood.c} due to
redwood driver removal.
Linus Torvalds [Tue, 10 Aug 2010 18:47:36 +0000 (11:47 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs:
omfs: fix uninitialized variable warning
omfs: sanity check cluster size
omfs: refuse to mount if bitmap pointer is obviously wrong
omfs: check bounds on block numbers before passing to sb_bread
omfs: fix memory leak
Linus Torvalds [Tue, 10 Aug 2010 18:39:13 +0000 (11:39 -0700)]
Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
fanotify: use both marks when possible
fsnotify: pass both the vfsmount mark and inode mark
fsnotify: walk the inode and vfsmount lists simultaneously
fsnotify: rework ignored mark flushing
fsnotify: remove global fsnotify groups lists
fsnotify: remove group->mask
fsnotify: remove the global masks
fsnotify: cleanup should_send_event
fanotify: use the mark in handler functions
audit: use the mark in handler functions
dnotify: use the mark in handler functions
inotify: use the mark in handler functions
fsnotify: send fsnotify_mark to groups in event handling functions
fsnotify: Exchange list heads instead of moving elements
fsnotify: srcu to protect read side of inode and vfsmount locks
fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
fsnotify: use _rcu functions for mark list traversal
fsnotify: place marks on object in order of group memory address
vfs/fsnotify: fsnotify_close can delay the final work in fput
fsnotify: store struct file not struct path
...
Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
Linus Torvalds [Tue, 10 Aug 2010 18:26:52 +0000 (11:26 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits)
no need for list_for_each_entry_safe()/resetting with superblock list
Fix sget() race with failing mount
vfs: don't hold s_umount over close_bdev_exclusive() call
sysv: do not mark superblock dirty on remount
sysv: do not mark superblock dirty on mount
btrfs: remove junk sb_dirt change
BFS: clean up the superblock usage
AFFS: wait for sb synchronization when needed
AFFS: clean up dirty flag usage
cifs: truncate fallout
mbcache: fix shrinker function return value
mbcache: Remove unused features
add f_flags to struct statfs(64)
pass a struct path to vfs_statfs
update VFS documentation for method changes.
All filesystems that need invalidate_inode_buffers() are doing that explicitly
convert remaining ->clear_inode() to ->evict_inode()
Make ->drop_inode() just return whether inode needs to be dropped
fs/inode.c:clear_inode() is gone
fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (59 commits)
igbvf.txt: Add igbvf Documentation
igb.txt: Add igb documentation
e100/e1000*/igb*/ixgb*: Add missing read memory barrier
ixgbe: fix build error with FCOE_CONFIG without DCB_CONFIG
netxen: protect tx timeout recovery by rtnl lock
isdn: gigaset: use after free
isdn: gigaset: add missing unlock
solos-pci: Fix race condition in tasklet RX handling
pkt_sched: Fix sch_sfq vs tcf_bind_filter oops
net: disable preemption before call smp_processor_id()
tcp: no md5sig option size check bug
iwlwifi: fix locking assertions
iwlwifi: fix TX tracer
isdn: fix information leak
net: Fix napi_gro_frags vs netpoll path
usbnet: remove noisy and hardly useful printk
rtl8180: avoid potential NULL deref in rtl8180_beacon_work
ath9k: Remove myself from the MAINTAINERS list
libertas: scan before assocation if no BSSID was given
libertas: fix association with some APs by using extended rates
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
tx493xide: use min_t() macro instead of min()
drivers/ide: Use memdup_user
via82cxxx: fix typo for VT6415 PCIE PATA IDE Host Controller support.
ide-cd: Do not access completed requests in the irq handler
qiaochong [Tue, 10 Aug 2010 00:21:27 +0000 (17:21 -0700)]
drivers/char/vt.c:vc_do_resize(): local var `end' should be unsigned long
According include/linux/console_struct.h,vc_scr_end is unsigned long.
struct vc_data {
unsigned short vc_num; /* Console number */
unsigned int vc_cols; /* [#] Console size */
unsigned int vc_rows;
unsigned int vc_size_row; /* Bytes per row */
unsigned int vc_scan_lines; /* # of scan lines */
unsigned long vc_origin; /* [!] Start of real screen */
unsigned long vc_scr_end; /* [!] End of real screen */
unsigned long vc_visible_origin; /* [!] Top of visible window */
unsigned int vc_top, vc_bottom; /* Scrolling region */
const struct consw *vc_sw;
unsigned short *vc_screenbuf;
...
}
Signed-off-by: qiaochong <qiaochong@loongson.cn> Cc: Greg KH <greg@kroah.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>
qiaochong [Tue, 10 Aug 2010 00:21:23 +0000 (17:21 -0700)]
drivers/char/vt.c: fix vc->vc_origin on take_over_console()
kernel will die on some platform when switch from vga mode to framebuffer
mode. The reason of this bug is that bind_con_driver reset vc->vc_origin
to (unsigned long)vc->vc_screenbuf.
On vgacon vc->vc_origin is not releated to vc->vc_screenbuf,if set
vc->vc_origin to vc->vc_screenbuf,kernel will die on vc_do_resize.
static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
struct vc_data *vc, unsigned int cols, unsigned int lines)
{
unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
unsigned int old_cols, old_rows, old_row_size, old_screen_size;
unsigned int new_cols, new_rows, new_row_size, new_screen_size;
unsigned int end, user;
...
end = (old_rows > new_rows) ? old_origin +
(old_row_size * new_rows) :
vc->vc_scr_end;
...
/*
here for a test from vgacon to framebuffer:
old_origin=0x810814a0,end=0xb00b8fa0,vc->vc_origin=0x810814a0
the code bellow will copy memory from 0x810814a0 to 0xb00b8fa0,
this will cover kernel code,kernel died here.
*/
while (old_origin < end) {
scr_memcpyw((unsigned short *) new_origin,
(unsigned short *) old_origin, rlth);
if (rrem)
scr_memsetw((void *)(new_origin + rlth),
vc->vc_video_erase_char, rrem);
old_origin += old_row_size;
new_origin += new_row_size;
}
rwsem: smaller wrappers around rwsem_down_failed_common
More code can be pushed from rwsem_down_read_failed and
rwsem_down_write_failed into rwsem_down_failed_common.
Following change adding down_read_critical infrastructure support also
enjoys having flags available in a register rather than having to fish it
out in the struct rwsem_waiter...
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> 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>
rwsem: wake queued readers when writer blocks on active read lock
This change addresses the following situation:
- Thread A acquires the rwsem for read
- Thread B tries to acquire the rwsem for write, notices there is already
an active owner for the rwsem.
- Thread C tries to acquire the rwsem for read, notices that thread B already
tried to acquire it.
- Thread C grabs the spinlock and queues itself on the wait queue.
- Thread B grabs the spinlock and queues itself behind C. At this point A is
the only remaining active owner on the rwsem.
In this situation thread B could notice that it was the last active writer
on the rwsem, and decide to wake C to let it proceed in parallel with A
since they both only want the rwsem for read.
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> 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>
rwsem: let RWSEM_WAITING_BIAS represent any number of waiting threads
Previously each waiting thread added a bias of RWSEM_WAITING_BIAS. With
this change, the bias is added only once to indicate that the wait list is
non-empty.
This has a few nice properties which will be used in following changes:
- when the spinlock is held and the waiter list is known to be non-empty,
count < RWSEM_WAITING_BIAS <=> there is an active writer on that sem
- count == RWSEM_WAITING_BIAS <=> there are waiting threads and no
active readers/writers on that sem
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> 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>
rwsem: lighter active count checks when waking up readers
In __rwsem_do_wake(), we can skip the active count check unless we come
there from up_xxxx(). Also when checking the active count, it is not
actually necessary to increment it; this allows us to get rid of the read
side undo code and simplify the calculation of the final rwsem count
adjustment once we've counted the reader threads to wake.
The basic observation is the following. When there are waiter threads on
a rwsem and the spinlock is held, other threads can only increment the
active count by trying to grab the rwsem in down_xxxx(). However
down_xxxx() will notice there are waiter threads and take the down_failed
path, blocking to acquire the spinlock on the way there. Therefore, a
thread observing an active count of zero with waiters queued and the
spinlock held, is protected against other threads acquiring the rwsem
until it wakes the last waiter or releases the spinlock.
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> 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>
rwsem: fully separate code paths to wake writers vs readers
This is in preparation for later changes in the series.
In __rwsem_do_wake(), the first queued waiter is checked first in order to
determine whether it's a writer or a reader. The code paths diverge at
this point. The code that checks and increments the rwsem active count is
duplicated on both sides - the point is that later changes in the series
will be able to independently modify both sides.
Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> 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>
hwmon: f71882fg: add support for the Fintek F71808E
Allow device probing to recognise the Fintek F71808E.
Sysfs interface:
* Fan/pwm control is the same as for F71889FG
* Temperature and voltage sensor handling is largely the same as for
the F71889FG
- Has one temperature sensor less (doesn't have temp3)
- Misses one voltage sensor (doesn't have V6, thus in6_input refers to
what in7_input refers for F71889FG)
For the purpose of the sysfs interface fxxxx_in_temp_attr[] is split up
such that it can largely be reused.
Signed-off-by: Giel van Schijndel <me@mortis.eu> Cc: Jean Delvare <khali@linux-fr.org> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
register_hotcpu_notifier() is designed to make these ifdefs unnecessary.
Cc: Chen Gong <gong.chen@linux.intel.com> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Huaxu Wan <huaxu.wan@intel.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Gong [Tue, 10 Aug 2010 00:21:10 +0000 (17:21 -0700)]
hwmon: coretemp: documentation update and cleanup
Update coretemp supported CPU TjMax lists and some cleanup work.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Huaxu Wan <huaxu.wan@intel.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If one coretemp device can't be added, it should allow subsequent adding
operation because every new-added device will create a new sysfs group,
not an additional sensor sys entry.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Huaxu Wan <huaxu.wan@intel.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Gong [Tue, 10 Aug 2010 00:21:09 +0000 (17:21 -0700)]
hwmon: coretemp: update hotplug condition check
Fix two errors in hotplug. One is for hotplug notifier. The other is
unnecessary driver unregister. Because even none of online cpus supports
coretemp, we can't assume new onlined cpu doesn't support it either. If
related driver is unregistered there we have no chance to use coretemp
from then on.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Huaxu Wan <huaxu.wan@intel.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guenter Roeck [Tue, 10 Aug 2010 00:21:08 +0000 (17:21 -0700)]
hwmon: add support for JEDEC JC 42.4 compliant temperature sensors
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guenter Roeck [Tue, 10 Aug 2010 00:21:06 +0000 (17:21 -0700)]
hwmon: driver for SMM665 Six-Channel Active DC Output Controller/Monitor
This driver adds support for the monitoring features of the Summit
Microelectronics SMM665 Six-Channel Active DC Output Controller/Monitor.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Jean Delvare <khali@linux-fr.org> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/hwmon/hdaps.c: add Lenovo Thinkpad T400 to the whitelist
Add Lenovo Thinkpad T400. I have done the testing on my laptop. The
hdaps module detects the device and the hdapsd daemon is able to [un]park
the disk.
Signed-off-by: Ritesh Raj Sarraf <rrs@debian.org> Cc: Frank Seidel <frank@f-seidel.de> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are caused by checkpatch incorrectly parsing its internal
representation of a statement block for struct's (or anything else that is
a statement block encapsulated in {}'s that also ends with a ';'). Fix
this by properly parsing a statement block.
Patrick Pannuto [Tue, 10 Aug 2010 00:21:02 +0000 (17:21 -0700)]
checkpatch: warn about unexpectedly long msleep's
As explained in Documentation/timers/timers-howto.txt, msleep's of < 20ms
may sleep for as long as 20ms. Caller's of msleep(1) or msleep(2), etc
are likely not to expect this quirky behavior - warn them.
Signed-off-by: Patrick Pannuto <ppannuto@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patrick Pannuto [Tue, 10 Aug 2010 00:21:01 +0000 (17:21 -0700)]
checkpatch: prefer usleep_range over udelay
When possible, sleeping is (usually) better than delaying; however, don't
bother callers of udelay < 10us, as those cases are generally not worth
the switch to usleep
[akpm@linux-foundation.org: fix mismatched parentheses] Signed-off-by: Patrick Pannuto <ppannuto@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Tue, 10 Aug 2010 00:21:01 +0000 (17:21 -0700)]
checkpatch: add more exceptions to 80 char lines
Add new logging functions netdev_<level> and netif_<level>.
Don't complain if the only thing on a line is a quoted string.
Signed-off-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Eloff [Tue, 10 Aug 2010 00:21:00 +0000 (17:21 -0700)]
checkpatch: change externals to globals
Make error message say 'ERROR: do not initialise globals to 0 or NULL'
rather than 'ERROR: do not initialise externals to 0 or NULL'. Makes more
sense in the context since there is an extern keyword in C and that is a
global declaration within the scope of the current file.
Signed-off-by: Joe Eloff <kagen101@gmail.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I've got a false positive when spaces are present at the beginning of a
line.
So I add this check, obviously excluding to check the lines in the middle of
comments.
For instance this code passes the checkpatch test:
+struct davinci_mcbsp_data {
+ unsigned int fmt;
+ int clk_div;
+};
+
+static struct davinci_mcbsp_data mcbsp_data;
Where, before the string "int clk_div", I have 4 spaces (\040
ascii character).
With v2.6.34 scripts/checkpatch.pl script I get:
scripts/checkpatch.pl 0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch
total: 0 errors, 0 warnings, 201 lines checked
0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch has no obvious style
problems and is ready for submission.
That is not correct. Instead with the proposed patch I get:
scripts/checkpatch.pl 0001-ASoC-DaVinci-Added-support-for-stereo-I2S.patch
WARNING: please, no space for starting a line,
excluding comments
#63: FILE: sound/soc/davinci/davinci-i2s.c:165:
+ int clk_div;$
WARNING: please, no space for starting a line,
excluding comments
#95: FILE: sound/soc/davinci/davinci-i2s.c:406:
+ return 0;$
total: 0 errors, 2 warnings, 201 lines checked
That is correct.
Signed-off-by: Raffaele Recalcati <raffaele.recalcati@bticino.it> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wolfram Sang [Tue, 10 Aug 2010 00:20:57 +0000 (17:20 -0700)]
checkpatch: refactor 'allowed asm includes' and add memory.h
Change the check suggesting replacement of asm-includes with
linux-includes. Exceptions to this rule are easier to extend now. Add
memory.h because ARM has a custom one.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Paris [Tue, 10 Aug 2010 00:20:56 +0000 (17:20 -0700)]
flex_array: add helpers to get and put to make pointers easy to use
Getting and putting arrays of pointers with flex arrays is a PITA. You
have to remember to pass &ptr to the _put and you have to do weird and
wacky casting to get the ptr back from the _get. Add two functions
flex_array_get_ptr() and flex_array_put_ptr() to handle all of the magic.
[akpm@linux-foundation.org: simplification suggested by Joe] Signed-off-by: Eric Paris <eparis@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: James Morris <jmorris@namei.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Baruch Siach [Tue, 10 Aug 2010 00:20:53 +0000 (17:20 -0700)]
list debugging: warn when deleting a deleted entry
Use the magic LIST_POISON* values to detect an incorrect use of list_del
on a deleted entry. This DEBUG_LIST specific warning is easier to
understand than the generic Oops message caused by LIST_POISON
dereference.
Signed-off-by: Baruch Siach <baruch@tkos.co.il> Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Tue, 10 Aug 2010 00:20:49 +0000 (17:20 -0700)]
MAINTAINERS: add patterns to PS3VRAM DRIVER
Signed-off-by: Joe Perches <joe@perches.com> Cc: Jim Paris <jim@jtan.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Tue, 10 Aug 2010 00:20:48 +0000 (17:20 -0700)]
MAINTAINERS: add patterns to OMAP USB
Signed-off-by: Joe Perches <joe@perches.com> Cc: Felipe Balbi <felipe.balbi@nokia.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Ben Nizette <bn@niasdigital.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Joe Perches <joe@perches.com> Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Akinobu Mita [Tue, 10 Aug 2010 00:20:35 +0000 (17:20 -0700)]
char: add WARN_ON() in misc_deregister()
misc_deregister() returns an error only when it attempts to unregister
the device that is not registered. This is the driver's bug.
Most of the drivers don't check the return value of misc_deregister().
(It is not bad thing because most of kernel *_unregister() API always
succeed and do not return value)
So it is better to indicate the error by WARN_ON() in misc_deregister().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Richard Kennedy [Tue, 10 Aug 2010 00:20:34 +0000 (17:20 -0700)]
stop_machine: struct cpu_stopper, remove alignment padding on 64 bits
Reorder elements in structure cpu_stopper to remove alignment padding on
64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes
per cpu.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Acked-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> 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>
Kevin Winchester [Tue, 10 Aug 2010 00:20:32 +0000 (17:20 -0700)]
init/main.c: mark do_one_initcall* as __init_or_module
Andrew Morton suggested that the do_one_initcall and do_one_initcall_debug
functions can be marked __init_or_module such that they can be discarded
for the CONFIG_MODULES=N case.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> 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>
Oleg Nesterov [Tue, 10 Aug 2010 00:20:30 +0000 (17:20 -0700)]
sys_personality: remove the bogus checks in sys_personality()->__set_personality() path
Cleanup, no functional changes.
- __set_personality() always changes ->exec_domain/personality, the
special case when ->exec_domain remains the same buys nothing but
complicates the code. Unify both cases to simplify the code.
- The -EINVAL check in sys_personality() was never right. If we assume
that set_personality() can fail we should check the value it returns
instead of verifying that task->personality was actually changed.
Remove it. Before the previous patch it was possible to hit this case
due to overflow problems, but this -EINVAL just indicated the kernel
bug.
OTOH, probably it makes sense to change lookup_exec_domain() to return
ERR_PTR() instead of default_exec_domain if the search in exec_domains
list fails, and report this error to the user-space. But this means
another user-space change, and we have in-kernel users which need fixes.
For example, PER_OSF4 falls into PER_MASK for unkown reason and nobody
cares to register this domain.
Christoph Mair [Tue, 10 Aug 2010 00:20:28 +0000 (17:20 -0700)]
drivers/misc: support for the pressure sensor BMP085 from Bosch Sensortec
This driver adds support for the BMP085 digital pressure sensor from Bosch
Sensortec. It exposes a sysfs api to userspace where pressure and
temperature measurement results can be read from the pressure0_input and
temp0_input file. The chip is able to calculate the average of up to
eight samples to increase the accuracy. This feature can be controlled by
writing to the oversampling file.
The BMP085 digital pressure sensor can measure ambient air pressure and
temperature. Both values can be obtained from sysfs files. The pressure
is measured by reading from pressure0_input. Valid values range from
30000 to 110000 pascal with a resolution of 1 pascal (=0.01 millibar).
temp0_input holds the current temperature in degree celsius, multiplied by
10. This results in a resolution of a tenth degree celsius. Values range
from -400 to 850.
To increase the accuracy, this chip can calculate the average of 1, 2, 4
or 8 samples. This behavior is controlled through the oversampling sysfs
file. Two to the power of the value written to that file specifies how
many samples will be used. Valid values: 0..3.
[akpm@linux-foundation.org: fix typo]
[shubhrajyoti@ti.com: optimize the wait time for the pressure sensor, definition of long is arch dependent so make it u32]
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Mair <christoph.mair@gmail.com> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for ROHM BH1780GLI Ambient light sensor.
BH1780 supports I2C interface. Driver supports read/update of power state
and read of lux value (through SYSFS). Writing value 3 to power_state
enables the sensor and current lux value could be read.
Currently this driver follows the same sysfs convention as supported by
drivers/misc/isl29003.c.
Signed-off-by: Hemanth V <hemanthv@ti.com> Reviewed-by: Daniel Mack <daniel@caiaq.de> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Jean Delvare <khali@linux-fr.org> Cc: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexey Fomenko [Tue, 10 Aug 2010 00:20:24 +0000 (17:20 -0700)]
scripts/mod/modpost.c: fix memory leak
sec2annotation returns malloc'ed buffer directly to printf as an argument.
Free this buffer after printing.
Signed-off-by: Alexey Fomenko <ext-alexey.fomenko@nokia.com> Cc: Trevor Keith <tsrk@tsrk.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since every caller of iommu_num_pages passes in a constant power of two
we can inline this such that the divide is replaced by a shift. The
entire function is only a few instructions once optimised, so it is
a good candidate for inlining overall.
Signed-off-by: Anton Blanchard <anton@samba.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/readdir.c: In function `filldir64':
fs/readdir.c:240:15: warning: `dirent' is used uninitialized in this function
fs/readdir.c: In function `filldir':
fs/readdir.c:155:15: warning: `dirent' is used uninitialized in this function
fs/compat.c: In function `compat_filldir64':
fs/compat.c:1071:11: warning: `dirent' is used uninitialized in this function
fs/compat.c: In function `compat_filldir':
fs/compat.c:984:15: warning: `dirent' is used uninitialized in this function
The warnings are related to the use of the NAME_OFFSET() macro. Luckily,
it appears as though the standard offsetof() macro is what is being
implemented by NAME_OFFSET(), thus we can fix the warning and use a more
standard code construct at the same time.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Egger [Tue, 10 Aug 2010 00:20:16 +0000 (17:20 -0700)]
arch/um/kernel/ptrace.c: remove dead PROC_MM
PROC_MM doesn't exist in Kconfig. Looking around it looks like a
left-over from 2.6.0 or even 2.4 times, last mentioned in a fedora patch
for 2.6.10. I believe it's time to get rid of that last tiny parts here
that are still around.
Signed-off-by: Christoph Egger <siccegge@cs.fau.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>
Signed-off-by: Richard Weinberger <richard@nod.at> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ai Li [Tue, 10 Aug 2010 00:20:13 +0000 (17:20 -0700)]
cpuidle: extend cpuidle and menu governor to handle dynamic states
On some SoC chips, HW resources may be in use during any particular idle
period. As a consequence, the cpuidle states that the SoC is safe to
enter can change from idle period to idle period. In addition, the
latency and threshold of each cpuidle state can vary, depending on the
operating condition when the CPU becomes idle, e.g. the current cpu
frequency, the current state of the HW blocks, etc.
cpuidle core and the menu governor, in the current form, are geared
towards cpuidle states that are static, i.e. the availabiltiy of the
states, their latencies, their thresholds are non-changing during run
time. cpuidle does not provide any hook that cpuidle drivers can use to
adjust those values on the fly for the current idle period before the menu
governor selects the target cpuidle state.
This patch extends cpuidle core and the menu governor to handle states
that are dynamic. There are three additions in the patch and the patch
maintains backwards-compatibility with existing cpuidle drivers.
1) add prepare() to struct cpuidle_device. A cpuidle driver can hook
into the callback and cpuidle will call prepare() before calling the
governor's select function. The callback gives the cpuidle driver a
chance to update the dynamic information of the cpuidle states for the
current idle period, e.g. state availability, latencies, thresholds,
power values, etc.
2) add CPUIDLE_FLAG_IGNORE as one of the state flags. In the prepare()
function, a cpuidle driver can set/clear the flag to indicate to the
menu governor whether a cpuidle state should be ignored, i.e. not
available, during the current idle period.
3) add power_specified bit to struct cpuidle_device. The menu governor
currently assumes that the cpuidle states are arranged in the order of
increasing latency, threshold, and power savings. This is true or can
be made true for static states. Once the state parameters are dynamic,
the latencies, thresholds, and power savings for the cpuidle states can
increase or decrease by different amounts from idle period to idle
period. So the assumption of increasing latency, threshold, and power
savings from Cn to C(n+1) can no longer be guaranteed.
It can be straightforward to calculate the power consumption of each
available state and to specify it in power_usage for the idle period.
Using the power_usage fields, the menu governor then selects the state
that has the lowest power consumption and that still satisfies all other
critieria. The power_specified bit defaults to 0. For existing cpuidle
drivers, cpuidle detects that power_specified is 0 and fills in a dummy
set of power_usage values.
Signed-off-by: Ai Li <aili@codeaurora.org> Cc: Len Brown <len.brown@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When taking a memory snapshot in hibernate_snapshot(), all (directly
called) memory allocations use GFP_ATOMIC. Hence swap misusage during
hibernation never occurs.
But from a pessimistic point of view, there is no guarantee that no page
allcation has __GFP_WAIT. It is better to have a global indication "we
enter hibernation, don't use swap!".
This patch tries to freeze new-swap-allocation during hibernation. (All
user processes are frozenm so swapin is not a concern).
This way, no updates will happen to swap_map[] between
hibernate_snapshot() and save_image(). Swap is thawed when swsusp_free()
is called. We can be assured that swap corruption will not occur.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: fix corruption of hibernation caused by reusing swap during image saving
Since 2.6.31, swap_map[]'s refcounting was changed to show that a used
swap entry is just for swap-cache, can be reused. Then, while scanning
free entry in swap_map[], a swap entry may be able to be reclaimed and
reused. It was caused by commit c9e444103b5e7a5 ("mm: reuse unused swap
entry if necessary").
But this caused deta corruption at resume. The scenario is
- Assume a clean-swap cache, but mapped.
- at hibernation_snapshot[], clean-swap-cache is saved as
clean-swap-cache and swap_map[] is marked as SWAP_HAS_CACHE.
- then, save_image() is called. And reuse SWAP_HAS_CACHE entry to save
image, and break the contents.
After resume:
- the memory reclaim runs and finds clean-not-referenced-swap-cache and
discards it because it's marked as clean. But here, the contents on
disk and swap-cache is inconsistent.
Hance memory is corrupted.
This patch avoids the bug by not reclaiming swap-entry during hibernation.
This is a quick fix for backporting.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Ondreg Zary <linux@rainbow-software.org> Tested-by: Ondreg Zary <linux@rainbow-software.org> Tested-by: Andrea Gelmini <andrea.gelmini@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Cree [Tue, 10 Aug 2010 00:20:08 +0000 (17:20 -0700)]
alpha: implement HW performance events on the EV67 and later CPUs
This implements hardware performance events for the EV67 and later CPUs
within the Linux performance events subsystem. Only using the performance
monitoring unit in HP/Compaq's so called "Aggregrate mode" is supported.
The code has been implemented in a manner that makes extension to other
older Alpha CPUs relatively straightforward should some mug wish to
indulge themselves.
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jay Estabrook <jay.estabrook@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Cree [Tue, 10 Aug 2010 00:20:07 +0000 (17:20 -0700)]
alpha: add wrperfmon.h header file to aid use of wrperfmon PALcall
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jay Estabrook <jay.estabrook@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Cree [Tue, 10 Aug 2010 00:20:05 +0000 (17:20 -0700)]
alpha: add performance monitor interrupt counter
The following patches implement hardware performance events for the Alpha
EV67 and later CPUs. I have had this running on a Compaq XP1000 (EV67,
single CPU) for a few days now. Pretty cool -- discovered that the glibc
exp2() library routine uses on average 985 cycles to execute 777 CPU
instructions whereas Compaq's CPML library version of exp2() uses on
average 32 cycles to execute 47 CPU instructions to achieve the same
thing!
This patch:
Add performance monitor interrupt counternd and export the count to user
space via /proc/interrupts.
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jay Estabrook <jay.estabrook@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Tue, 10 Aug 2010 00:20:03 +0000 (17:20 -0700)]
mm: avoid resetting wb_start after each writeback round
WB_SYNC_NONE writeback is done in rounds of 1024 pages so that we don't
write out some huge inode for too long while starving writeout of other
inodes. To avoid livelocks, we record time we started writeback in
wbc->wb_start and do not write out inodes which were dirtied after this
time. But currently, writeback_inodes_wb() resets wb_start each time it
is called thus effectively invalidating this logic and making any
WB_SYNC_NONE writeback prone to livelocks.
This patch makes sure wb_start is set only once when we start writeback.
Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wu Fengguang [Tue, 10 Aug 2010 00:20:01 +0000 (17:20 -0700)]
vmscan: raise the bar to PAGEOUT_IO_SYNC stalls
Fix "system goes unresponsive under memory pressure and lots of
dirty/writeback pages" bug.
http://lkml.org/lkml/2010/4/4/86
In the above thread, Andreas Mohr described that
Invoking any command locked up for minutes (note that I'm
talking about attempted additional I/O to the _other_,
_unaffected_ main system HDD - such as loading some shell
binaries -, NOT the external SSD18M!!).
This happens when the two conditions are both meet:
- under memory pressure
- writing heavily to a slow device
OOM also happens in Andreas' system. The OOM trace shows that 3 processes
are stuck in wait_on_page_writeback() in the direct reclaim path. One in
do_fork() and the other two in unix_stream_sendmsg(). They are blocked on
this condition:
(sc->order && priority < DEF_PRIORITY - 2)
which was introduced in commit 78dc583d (vmscan: low order lumpy reclaim
also should use PAGEOUT_IO_SYNC) one year ago. That condition may be too
permissive. In Andreas' case, 512MB/1024 = 512KB. If the direct reclaim
for the order-1 fork() allocation runs into a range of 512KB
hard-to-reclaim LRU pages, it will be stalled.
It's a severe problem in three ways.
Firstly, it can easily happen in daily desktop usage. vmscan priority can
easily go below (DEF_PRIORITY - 2) on _local_ memory pressure. Even if
the system has 50% globally reclaimable pages, it still has good
opportunity to have 0.1% sized hard-to-reclaim ranges. For example, a
simple dd can easily create a big range (up to 20%) of dirty pages in the
LRU lists. And order-1 to order-3 allocations are more than common with
SLUB. Try "grep -v '1 :' /proc/slabinfo" to get the list of high order
slab caches. For example, the order-1 radix_tree_node slab cache may
stall applications at swap-in time; the order-3 inode cache on most
filesystems may stall applications when trying to read some file; the
order-2 proc_inode_cache may stall applications when trying to open a
/proc file.
Secondly, once triggered, it will stall unrelated processes (not doing IO
at all) in the system. This "one slow USB device stalls the whole system"
avalanching effect is very bad.
Thirdly, once stalled, the stall time could be intolerable long for the
users. When there are 20MB queued writeback pages and USB 1.1 is writing
them in 1MB/s, wait_on_page_writeback() will stuck for up to 20 seconds.
Not to mention it may be called multiple times.
So raise the bar to only enable PAGEOUT_IO_SYNC when priority goes below
DEF_PRIORITY/3, or 6.25% LRU size. As the default dirty throttle ratio is
20%, it will hardly be triggered by pure dirty pages. We'd better treat
PAGEOUT_IO_SYNC as some last resort workaround -- its stall time is so
uncomfortably long (easily goes beyond 1s).
The bar is only raised for (order < PAGE_ALLOC_COSTLY_ORDER) allocations,
which are easy to satisfy in 1TB memory boxes. So, although 6.25% of
memory could be an awful lot of pages to scan on a system with 1TB of
memory, it won't really have to busy scan that much.
Andreas tested an older version of this patch and reported that it mostly
fixed his problem. Mel Gorman helped improve it and KOSAKI Motohiro will
fix it further in the next patch.
Reported-by: Andreas Mohr <andi@lisas.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Wu Fengguang <fengguang.wu@intel.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>
projects / linux-beck.git / log