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All these lists moved to lists.ozlabs.org quite a while ago.
Signed-off-by: Stephen Rothwell <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Chapter 6 is right about mutex_trylock, but chapter 10 wasn't. This error
was introduced during semaphore-to-mutex conversion of the Unreliable
guide. :-)
If user context which performs mutex_lock() or mutex_trylock() is
preempted by interrupt context which performs mutex_trylock() on the same
mutex instance, a deadlock occurs. This is because these functions do not
disable local IRQs when they operate on mutex->wait_lock.
Signed-off-by: Stefan Richter <[email protected]>
Acked-by: Rusty Russell <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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gcc-4.0.2:
drivers/scsi/qla4xxx/ql4_os.c: In function 'qla4_8xxx_error_recovery':
drivers/scsi/qla4xxx/ql4_glbl.h:135: sorry, unimplemented: inlining failed in call to 'qla4_8xxx_set_drv_active': function body not available
drivers/scsi/qla4xxx/ql4_os.c:2377: sorry, unimplemented: called from here
drivers/scsi/qla4xxx/ql4_glbl.h:135: sorry, unimplemented: inlining failed in call to 'qla4_8xxx_set_drv_active': function body not available
drivers/scsi/qla4xxx/ql4_os.c:2393: sorry, unimplemented: called from here
Cc: Ravi Anand <[email protected]>
Cc: Vikas Chaudhary <[email protected]>
Cc: James Bottomley <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Fix uml compile error:
include/linux/dma-mapping.h:145: error: redefinition of 'dma_get_cache_alignment'
arch/um/include/asm/dma-mapping.h:99: note: previous definition of 'dma_get_cache_alignment' was here
Introduced by commit 4565f0170dfc ("dma-mapping: unify
dma_get_cache_alignment implementations")
Signed-off-by: Miklos Szeredi <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: FUJITA Tomonori <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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dump_tasks() needs to hold the RCU read lock around its access of the
target task's UID. To this end it should use task_uid() as it only needs
that one thing from the creds.
The fact that dump_tasks() holds tasklist_lock is insufficient to prevent the
target process replacing its credentials on another CPU.
Then, this patch change to call rcu_read_lock() explicitly.
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
mm/oom_kill.c:410 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
4 locks held by kworker/1:2/651:
#0: (events){+.+.+.}, at: [<ffffffff8106aae7>]
process_one_work+0x137/0x4a0
#1: (moom_work){+.+...}, at: [<ffffffff8106aae7>]
process_one_work+0x137/0x4a0
#2: (tasklist_lock){.+.+..}, at: [<ffffffff810fafd4>]
out_of_memory+0x164/0x3f0
#3: (&(&p->alloc_lock)->rlock){+.+...}, at: [<ffffffff810fa48e>]
find_lock_task_mm+0x2e/0x70
Signed-off-by: KOSAKI Motohiro <[email protected]>
Signed-off-by: David Howells <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Acked-by: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Commit 0aad4b3124 ("oom: fold __out_of_memory into out_of_memory")
introduced a tasklist_lock leak. Then it caused following obvious
danger warnings and panic.
================================================
[ BUG: lock held when returning to user space! ]
------------------------------------------------
rsyslogd/1422 is leaving the kernel with locks still held!
1 lock held by rsyslogd/1422:
#0: (tasklist_lock){.+.+.+}, at: [<ffffffff810faf64>] out_of_memory+0x164/0x3f0
BUG: scheduling while atomic: rsyslogd/1422/0x00000002
INFO: lockdep is turned off.
This patch fixes it.
Signed-off-by: KOSAKI Motohiro <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
Acked-by: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Commit b940fd7035 ("oom: remove unnecessary code and cleanup") added an
unnecessary NULL pointer dereference. remove it.
Signed-off-by: KOSAKI Motohiro <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
Acked-by: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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There's some merge problem between sdhic core and sdhci-s3c host. After
mutex is changed to spinlock. It needs to use use spin lock functions and
use the correct card detection function.
Signed-off-by: Kyungmin Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Some SDHCI controllers like s5pc110 don't have an HISPD bit in the HOSTCTL
register.
Signed-off-by: Kyungmin Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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s5pc110 (aka s5pv210) uses the same SDHCI IP.
Signed-off-by: Kyungmin Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Each board can override the default sdhci host capabilities.
Some board has broken features by hardwares and support 8-bit bandwidth.
Signed-off-by: Kyungmin Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When radix_tree_maxindex() is ~0UL, it can happen that scanning overflows
index and tree traversal code goes astray reading memory until it hits
unreadable memory. Check for overflow and exit in that case.
Signed-off-by: Jan Kara <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Nick Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Revert commit 7721fea3d0fd93fb4d000eb737b444369358d6d3 ("hwmon:
f71882fg: add support for the Fintek F71808E").
Hans said:
: A second review after I've received a data sheet for this device from
: Fintek has turned up a few bugs.
:
: Unfortunately Giel (nor I) have time to fix this in time for the 2.6.36
: cycle. Therefor I would like to see this patch reverted as not having any
: support for the hwmon function of this superio chip is better then having
: unreliable support.
Cc: Giel van Schijndel <[email protected]>
Cc: Jean Delvare <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Provide a check in all the kfifo examples to validate the correct
execution of each testcase.
Signed-off-by: Andrea Righi <[email protected]>
Acked-by: Stefani Seibold <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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We use a dynamically allocated kfifo in the dma example, so we need to
free it when unloading the module.
Signed-off-by: Andrea Righi <[email protected]>
Acked-by: Stefani Seibold <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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The scatterlist is used uninitialized in kfifo_dma_in_prepare(). This
triggers the following bug if CONFIG_DEBUG_SG=y:
------------[ cut here ]------------
kernel BUG at include/linux/scatterlist.h:65!
invalid opcode: 0000 [#1] PREEMPT SMP
...
Call Trace:
[<ffffffff810a1eab>] setup_sgl+0x6b/0xe0
[<ffffffffa03d7000>] ? example_init+0x0/0x265 [dma_example]
[<ffffffff810a2021>] __kfifo_dma_in_prepare+0x21/0x30
[<ffffffffa03d7124>] example_init+0x124/0x265 [dma_example]
[<ffffffff810f9c55>] ? trace_module_notify+0x25/0x370
[<ffffffff81110c6e>] ? free_pages_prepare+0x11e/0x1e0
[<ffffffff8106f2b1>] ? get_parent_ip+0x11/0x50
[<ffffffff810f9c55>] ? trace_module_notify+0x25/0x370
[<ffffffff810b65fd>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff814beade>] ? mutex_unlock+0xe/0x10
[<ffffffff810f9c71>] ? trace_module_notify+0x41/0x370
[<ffffffff810a77d5>] ? __blocking_notifier_call_chain+0x45/0x80
[<ffffffff81137b7a>] ? vfree+0x2a/0x30
[<ffffffff810a6ac3>] ? up_read+0x23/0x40
[<ffffffff810a77f5>] ? __blocking_notifier_call_chain+0x65/0x80
[<ffffffff810001e3>] do_one_initcall+0x43/0x180
[<ffffffff810c577a>] sys_init_module+0xba/0x200
[<ffffffff8103819b>] system_call_fastpath+0x16/0x1b
RIP [<ffffffff810a1e31>] setup_sgl_buf+0x1a1/0x1b0
RSP <ffff88006720dc98>
---[ end trace a72b979fd3c1d3a5 ]---
Add the proper initialization to avoid the bug.
Signed-off-by: Andrea Righi <[email protected]>
Acked-by: Stefani Seibold <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Provide a static array of expected items that kfifo should contain at the
end of the test to validate it.
Signed-off-by: Andrea Righi <[email protected]>
Cc: Stefani Seibold <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add a testcase for kfifo_skip() to the byte stream fifo example.
Signed-off-by: Andrea Righi <[email protected]>
Cc: Greg KH <[email protected]>
Acked-by: Stefani Seibold <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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kfifo_skip() is currently broken, due to the missing of the internal
helper function. Add it.
Signed-off-by: Andrea Righi <[email protected]>
Cc: Greg KH <[email protected]>
Acked-by: Stefani Seibold <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Screen is completely corrupted since 2.6.34. Bisection revealed that it's
caused by commit 6175ddf06b61720 ("x86: Clean up mem*io functions.").
H. Peter Anvin explained that memcpy_toio() does not copy data in 32bit
chunks anymore on x86.
Signed-off-by: Ondrej Zary <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Petr Vandrovec <[email protected]>
Cc: Jean Delvare <[email protected]>
Cc: <[email protected]> [2.6.34.x, 2.6.35.x]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
kprobes/x86: Fix the return address of multiple kretprobes
perf tools: Fix build error on read only source.
perf, x86: Fix Intel-nhm PMU programming errata workaround
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Fix the return address of subsequent kretprobes when multiple
kretprobes are set on the same function.
For example:
# cd /sys/kernel/debug/tracing
# echo "r:event1 sys_symlink" > kprobe_events
# echo "r:event2 sys_symlink" >> kprobe_events
# echo 1 > events/kprobes/enable
# ln -s /tmp/foo /tmp/bar
(without this patch)
# cat trace
ln-897 [000] 20404.133727: event1: (kretprobe_trampoline+0x0/0x4c <- sys_symlink)
ln-897 [000] 20404.133747: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink)
(with this patch)
# cat trace
ln-740 [000] 13799.491076: event1: (system_call_fastpath+0x16/0x1b <- sys_symlink)
ln-740 [000] 13799.491096: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink)
Signed-off-by: KUMANO Syuhei <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: YOSHIFUJI Hideaki <[email protected]>
LKML-Reference: <1281853084.3254.11.camel@camp10-laptop>
Signed-off-by: Ingo Molnar <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent
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* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Fix an Oops in the NFSv4 atomic open code
NFS: Fix the selection of security flavours in Kconfig
NFS: fix the return value of nfs_file_fsync()
rpcrdma: Fix SQ size calculation when memreg is FRMR
xprtrdma: Do not truncate iova_start values in frmr registrations.
nfs: Remove redundant NULL check upon kfree()
nfs: Add "lookupcache" to displayed mount options
NFS: allow close-to-open cache semantics to apply to root of NFS filesystem
SUNRPC: fix NFS client over TCP hangs due to packet loss (Bug 16494)
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
USB HID: Add ID for eGalax Multitouch used in JooJoo tablet
HID: hiddev: fix memory corruption due to invalid intfdata
HID: hiddev: protect against disconnect/NULL-dereference race
HID: picolcd: correct ordering of framebuffer freeing
HID: picolcd: testing the wrong variable
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] Fix build error: conflicting types for ‘sys_execve’
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Fix the declaration of sys_execve() in asm-generic/syscalls.h to have
various consts applied to its pointers.
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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arch/ia64/kernel/process.c:636: error: conflicting types for ‘sys_execve’
commit d7627467b7a8dd6944885290a03a07ceb28c10eb
Make do_execve() take a const filename pointer
Missed the declaration of sys_execve in the ia64 asm/unistd.h (perhaps
because there is no reason for it to be there ... it might be a left over
from the COMPAT code?). Just delete the conflicting version.
Signed-off-by: Tony Luck <[email protected]>
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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:
fs: brlock vfsmount_lock
fs: scale files_lock
lglock: introduce special lglock and brlock spin locks
tty: fix fu_list abuse
fs: cleanup files_lock locking
fs: remove extra lookup in __lookup_hash
fs: fs_struct rwlock to spinlock
apparmor: use task path helpers
fs: dentry allocation consolidation
fs: fix do_lookup false negative
mbcache: Limit the maximum number of cache entries
hostfs ->follow_link() braino
hostfs: dumb (and usually harmless) tpyo - strncpy instead of strlcpy
remove SWRITE* I/O types
kill BH_Ordered flag
vfs: update ctime when changing the file's permission by setfacl
cramfs: only unlock new inodes
fix reiserfs_evict_inode end_writeback second call
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This fixes a build breakage introduced by commit 4c2ef25fe0b8 ("mmc: fix
all hangs related to mmc/sd card insert/removal during suspend/resume")
Cc: David Brownell <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: [email protected]
Cc: Andrew Morton <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Acked-by: Kukjin Kim <[email protected]>
Acked-by: Maxim Levitsky <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Parts of the build process were generating files outside the specified
O= directory, causing the build to fail on systems where the sources are
in a read only file system.
Fix it by using $(OUTPUT) on these locations.
Also check that $(OUTPUT) actually exists, just like the top level
kernel Makefile does. Otherwise the failure message emitted is
completely misleading.
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Kusanagi Kouichi <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf tools: Fix build on POSIX shells
latencytop: Fix kconfig dependency warnings
perf annotate tui: Fix exit and RIGHT keys handling
tracing: Sanitize value returned from write(trace_marker, "...", len)
tracing/events: Convert format output to seq_file
tracing: Extend recordmcount to better support Blackfin mcount
tracing: Fix ring_buffer_read_page reading out of page boundary
tracing: Fix an unallocated memory access in function_graph
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)
ALSA: hda - Fix ALC680 base model capture
ASoC: Remove DSP mode support for WM8776
ALSA: hda - Add quirk for Dell Vostro 1220
ALSA: riptide - Fix detection / load of firmware files
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git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68knommu: include sched.h in ColdFire/SPI driver
m68knommu: formatting of pointers in printk()
m68knommu: arch/m68k/include/asm/ide.h fix for nommu
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* 'for-linus' of git://neil.brown.name/md:
md raid-1/10 Fix bio_rw bit manipulations again
md: provide appropriate return value for spare_active functions.
md: Notify sysfs when RAID1/5/10 disk is In_sync.
Update recovery_offset even when external metadata is used.
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* 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6:
spi.h: missing kernel-doc notation, please fix
of: fix missing headers for of_address_to_resource() in MTD and SysACE drivers
of: Fix missing includes
ata: update for of_device to platform_device replacement
microblaze: Fix of: eliminate of_device->node and dev_archdata->{of,prom}_node
microblaze: Fix of/address: Merge all of the bus translation code
booting-without-of: Remove nonexistent chapters from TOC, fix numbering
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Adam Lackorzynski reports:
with 2.6.35.2 I'm getting this reproducible Oops:
[ 110.825396] BUG: unable to handle kernel NULL pointer dereference at
(null)
[ 110.828638] IP: [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[ 110.828638] PGD be89f067 PUD bf18f067 PMD 0
[ 110.828638] Oops: 0000 [#1] SMP
[ 110.828638] last sysfs file: /sys/class/net/lo/operstate
[ 110.828638] CPU 2
[ 110.828638] Modules linked in: rtc_cmos rtc_core rtc_lib amd64_edac_mod
i2c_amd756 edac_core i2c_core dm_mirror dm_region_hash dm_log dm_snapshot
sg sr_mod usb_storage ohci_hcd mptspi tg3 mptscsih mptbase usbcore nls_base
[last unloaded: scsi_wait_scan]
[ 110.828638]
[ 110.828638] Pid: 11264, comm: setchecksum Not tainted 2.6.35.2 #1
[ 110.828638] RIP: 0010:[<ffffffff811247b7>] [<ffffffff811247b7>]
encode_attrs+0x1a/0x2a4
[ 110.828638] RSP: 0000:ffff88003bf5b878 EFLAGS: 00010296
[ 110.828638] RAX: ffff8800bddb48a8 RBX: ffff88003bf5bb18 RCX:
0000000000000000
[ 110.828638] RDX: ffff8800be258800 RSI: 0000000000000000 RDI:
ffff88003bf5b9f8
[ 110.828638] RBP: 0000000000000000 R08: ffff8800bddb48a8 R09:
0000000000000004
[ 110.828638] R10: 0000000000000003 R11: ffff8800be779000 R12:
ffff8800be258800
[ 110.828638] R13: ffff88003bf5b9f8 R14: ffff88003bf5bb20 R15:
ffff8800be258800
[ 110.828638] FS: 0000000000000000(0000) GS:ffff880041e00000(0063)
knlGS:00000000556bd6b0
[ 110.828638] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b
[ 110.828638] CR2: 0000000000000000 CR3: 00000000be8ef000 CR4:
00000000000006e0
[ 110.828638] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 110.828638] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[ 110.828638] Process setchecksum (pid: 11264, threadinfo
ffff88003bf5a000, task ffff88003f232210)
[ 110.828638] Stack:
[ 110.828638] 0000000000000000 ffff8800bfbcf920 0000000000000000
0000000000000ffe
[ 110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[ 110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[ 110.828638] Call Trace:
[ 110.828638] [<ffffffff81124c1f>] ? nfs4_xdr_enc_setattr+0x90/0xb4
[ 110.828638] [<ffffffff81371161>] ? call_transmit+0x1c3/0x24a
[ 110.828638] [<ffffffff813774d9>] ? __rpc_execute+0x78/0x22a
[ 110.828638] [<ffffffff81371a91>] ? rpc_run_task+0x21/0x2b
[ 110.828638] [<ffffffff81371b7e>] ? rpc_call_sync+0x3d/0x5d
[ 110.828638] [<ffffffff8111e284>] ? _nfs4_do_setattr+0x11b/0x147
[ 110.828638] [<ffffffff81109466>] ? nfs_init_locked+0x0/0x32
[ 110.828638] [<ffffffff810ac521>] ? ifind+0x4e/0x90
[ 110.828638] [<ffffffff8111e2fb>] ? nfs4_do_setattr+0x4b/0x6e
[ 110.828638] [<ffffffff8111e634>] ? nfs4_do_open+0x291/0x3a6
[ 110.828638] [<ffffffff8111ed81>] ? nfs4_open_revalidate+0x63/0x14a
[ 110.828638] [<ffffffff811056c4>] ? nfs_open_revalidate+0xd7/0x161
[ 110.828638] [<ffffffff810a2de4>] ? do_lookup+0x1a4/0x201
[ 110.828638] [<ffffffff810a4733>] ? link_path_walk+0x6a/0x9d5
[ 110.828638] [<ffffffff810a42b6>] ? do_last+0x17b/0x58e
[ 110.828638] [<ffffffff810a5fbe>] ? do_filp_open+0x1bd/0x56e
[ 110.828638] [<ffffffff811cd5e0>] ? _atomic_dec_and_lock+0x30/0x48
[ 110.828638] [<ffffffff810a9b1b>] ? dput+0x37/0x152
[ 110.828638] [<ffffffff810ae063>] ? alloc_fd+0x69/0x10a
[ 110.828638] [<ffffffff81099f39>] ? do_sys_open+0x56/0x100
[ 110.828638] [<ffffffff81027a22>] ? ia32_sysret+0x0/0x5
[ 110.828638] Code: 83 f1 01 e8 f5 ca ff ff 48 83 c4 50 5b 5d 41 5c c3 41
57 41 56 41 55 49 89 fd 41 54 49 89 d4 55 48 89 f5 53 48 81 ec 18 01 00 00
<8b> 06 89 c2 83 e2 08 83 fa 01 19 db 83 e3 f8 83 c3 18 a8 01 8d
[ 110.828638] RIP [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[ 110.828638] RSP <ffff88003bf5b878>
[ 110.828638] CR2: 0000000000000000
[ 112.840396] ---[ end trace 95282e83fd77358f ]---
We need to ensure that the O_EXCL flag is turned off if the user doesn't
set O_CREAT.
Cc: [email protected]
Signed-off-by: Trond Myklebust <[email protected]>
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With some hardware combinations, the PCM interrupts are acknowledged
before the period boundary from the emu10k1 chip. The midlevel PCM code
gets confused and the playback stream is interrupted.
It seems that the interrupt processing shift by 2 samples is enough
to fix this issue. This default value does not harm other,
non-affected hardware.
More information: Kernel bugzilla bug#16300
[A copmile warning fixed by tiwai]
Signed-off-by: Jaroslav Kysela <[email protected]>
Cc: <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
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fs: brlock vfsmount_lock
Use a brlock for the vfsmount lock. It must be taken for write whenever
modifying the mount hash or associated fields, and may be taken for read when
performing mount hash lookups.
A new lock is added for the mnt-id allocator, so it doesn't need to take
the heavy vfsmount write-lock.
The number of atomics should remain the same for fastpath rlock cases, though
code would be slightly slower due to per-cpu access. Scalability is not not be
much improved in common cases yet, due to other locks (ie. dcache_lock) getting
in the way. However path lookups crossing mountpoints should be one case where
scalability is improved (currently requiring the global lock).
The slowpath is slower due to use of brlock. On a 64 core, 64 socket, 32 node
Altix system (high latency to remote nodes), a simple umount microbenchmark
(mount --bind mnt mnt2 ; umount mnt2 loop 1000 times), before this patch it
took 6.8s, afterwards took 7.1s, about 5% slower.
Cc: Al Viro <[email protected]>
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: scale files_lock
Improve scalability of files_lock by adding per-cpu, per-sb files lists,
protected with an lglock. The lglock provides fast access to the per-cpu lists
to add and remove files. It also provides a snapshot of all the per-cpu lists
(although this is very slow).
One difficulty with this approach is that a file can be removed from the list
by another CPU. We must track which per-cpu list the file is on with a new
variale in the file struct (packed into a hole on 64-bit archs). Scalability
could suffer if files are frequently removed from different cpu's list.
However loads with frequent removal of files imply short interval between
adding and removing the files, and the scheduler attempts to avoid moving
processes too far away. Also, even in the case of cross-CPU removal, the
hardware has much more opportunity to parallelise cacheline transfers with N
cachelines than with 1.
A worst-case test of 1 CPU allocating files subsequently being freed by N CPUs
degenerates to contending on a single lock, which is no worse than before. When
more than one CPU are allocating files, even if they are always freed by
different CPUs, there will be more parallelism than the single-lock case.
Testing results:
On a 2 socket, 8 core opteron, I measure the number of times the lock is taken
to remove the file, the number of times it is removed by the same CPU that
added it, and the number of times it is removed by the same node that added it.
Booting: locks= 25049 cpu-hits= 23174 (92.5%) node-hits= 23945 (95.6%)
kbuild -j16 locks=2281913 cpu-hits=2208126 (96.8%) node-hits=2252674 (98.7%)
dbench 64 locks=4306582 cpu-hits=4287247 (99.6%) node-hits=4299527 (99.8%)
So a file is removed from the same CPU it was added by over 90% of the time.
It remains within the same node 95% of the time.
Tim Chen ran some numbers for a 64 thread Nehalem system performing a compile.
throughput
2.6.34-rc2 24.5
+patch 24.9
us sys idle IO wait (in %)
2.6.34-rc2 51.25 28.25 17.25 3.25
+patch 53.75 18.5 19 8.75
So significantly less CPU time spent in kernel code, higher idle time and
slightly higher throughput.
Single threaded performance difference was within the noise of microbenchmarks.
That is not to say penalty does not exist, the code is larger and more memory
accesses required so it will be slightly slower.
Cc: [email protected]
Cc: Tim Chen <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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lglock: introduce special lglock and brlock spin locks
This patch introduces "local-global" locks (lglocks). These can be used to:
- Provide fast exclusive access to per-CPU data, with exclusive access to
another CPU's data allowed but possibly subject to contention, and to provide
very slow exclusive access to all per-CPU data.
- Or to provide very fast and scalable read serialisation, and to provide
very slow exclusive serialisation of data (not necessarily per-CPU data).
Brlocks are also implemented as a short-hand notation for the latter use
case.
Thanks to Paul for local/global naming convention.
Cc: [email protected]
Cc: Al Viro <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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tty: fix fu_list abuse
tty code abuses fu_list, which causes a bug in remount,ro handling.
If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".
Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.
The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.
[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]
Cc: [email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: Alan Cox <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: cleanup files_lock locking
Lock tty_files with a new spinlock, tty_files_lock; provide helpers to
manipulate the per-sb files list; unexport the files_lock spinlock.
Cc: [email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: Alan Cox <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: remove extra lookup in __lookup_hash
Optimize lookup for create operations, where no dentry should often be
common-case. In cases where it is not, such as unlink, the added overhead
is much smaller than the removed.
Also, move comments about __d_lookup racyness to the __d_lookup call site.
d_lookup is intuitive; __d_lookup is what needs commenting. So in that same
vein, add kerneldoc comments to __d_lookup and clean up some of the comments:
- We are interested in how the RCU lookup works here, particularly with
renames. Make that explicit, and point to the document where it is explained
in more detail.
- RCU is pretty standard now, and macros make implementations pretty mindless.
If we want to know about RCU barrier details, we look in RCU code.
- Delete some boring legacy comments because we don't care much about how the
code used to work, more about the interesting parts of how it works now. So
comments about lazy LRU may be interesting, but would better be done in the
LRU or refcount management code.
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: fs_struct rwlock to spinlock
struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.
Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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apparmor: use task path helpers
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: dentry allocation consolidation
There are 2 duplicate copies of code in dentry allocation in path lookup.
Consolidate them into a single function.
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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fs: fix do_lookup false negative
In do_lookup, if we initially find no dentry, we take the directory i_mutex and
re-check the lookup. If we find a dentry there, then we revalidate it if
needed. However if that revalidate asks for the dentry to be invalidated, we
return -ENOENT from do_lookup. What should happen instead is an attempt to
allocate and lookup a new dentry.
This is probably not noticed because it is rare. It is only reached if a
concurrent create races in first (in which case, the dentry probably won't be
invalidated anyway), or if the racy __d_lookup has failed due to a
false-negative (which is very rare).
Fix this by removing code and have it use the normal reval path.
Signed-off-by: Nick Piggin <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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