The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to
the mm_struct. It was a very good first step for sanitize OOM.
However Paul Menage reported the commit makes regression to his job
scheduler. Current OOM logic can kill OOM_DISABLED process.
Why? His program has the code of similar to the following.
...
set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */
...
if (vfork() == 0) {
set_oom_adj(0); /* Invoked child can be killed */
execve("foo-bar-cmd");
}
....
vfork() parent and child are shared the same mm_struct. then above
set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also
change oom_adj for vfork() parent. Then, vfork() parent (job scheduler)
lost OOM immune and it was killed.
Actually, fork-setting-exec idiom is very frequently used in userland program.
We must not break this assumption.
Then, this patch revert commit 2ff05b2b and related commit.
Reverted commit list
---------------------
- commit 2ff05b2b4e (oom: move oom_adj value from task_struct to mm_struct)
- commit 4d8b9135c3 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE)
- commit 8123681022 (oom: only oom kill exiting tasks with attached memory)
- commit 933b787b57 (mm: copy over oom_adj value at fork time)
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_sb_pseudo sets s_maxbytes to ~0ULL which becomes negative when cast
to a signed value. Fix it to use MAX_LFS_FILESIZE which casts properly
to a positive signed value.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Steve French <smfrench@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Robert Love <rlove@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix prompt for LSM_MMAP_MIN_ADDR.
(Verbs are cool!)
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Commit 788084aba2 added the LSM_MMAP_MIN_ADDR
option, whose help text states "For most ia64, ppc64 and x86 users with lots
of address space a value of 65536 is reasonable and should cause no problems."
Which implies that it's default setting was typoed.
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (60 commits)
net: restore gnet_stats_basic to previous definition
NETROM: Fix use of static buffer
e1000e: fix use of pci_enable_pcie_error_reporting
e1000e: WoL does not work on 82577/82578 with manageability enabled
cnic: Fix locking in init/exit calls.
cnic: Fix locking in start/stop calls.
bnx2: Use mutex on slow path cnic calls.
cnic: Refine registration with bnx2.
cnic: Fix symbol_put_addr() panic on ia64.
gre: Fix MTU calculation for bound GRE tunnels
pegasus: Add new device ID.
drivers/net: fixed drivers that support netpoll use ndo_start_xmit()
via-velocity: Fix test of mii_status bit VELOCITY_DUPLEX_FULL
rt2x00: fix memory corruption in rf cache, add a sanity check
ixgbe: Fix receive on real device when VLANs are configured
ixgbe: Do not return 0 in ixgbe_fcoe_ddp() upon FCP_RSP in DDP completion
netxen: free napi resources during detach
netxen: remove netxen workqueue
ixgbe: fix issues setting rx-usecs with legacy interrupts
can: fix oops caused by wrong rtnl newlink usage
...
will fix kernel oopses like the following:
# mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test1
# mount -t nilfs2 -r -o cp=20 /dev/sdb1 /test2
# umount /test1
# umount /test2
BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:1069
in_atomic(): 0, irqs_disabled(): 1, pid: 3886, name: umount.nilfs2
1 lock held by umount.nilfs2/3886:
#0: (&type->s_umount_key#31){+.+...}, at: [<c10b398a>] deactivate_super+0x52/0x6c
irq event stamp: 1219
hardirqs last enabled at (1219): [<c135c774>] __mutex_unlock_slowpath+0xf8/0x119
hardirqs last disabled at (1218): [<c135c6d5>] __mutex_unlock_slowpath+0x59/0x119
softirqs last enabled at (1214): [<c1033316>] __do_softirq+0x1a5/0x1ad
softirqs last disabled at (1205): [<c1033354>] do_softirq+0x36/0x5a
Pid: 3886, comm: umount.nilfs2 Not tainted 2.6.31-rc6 #55
Call Trace:
[<c1023549>] __might_sleep+0x107/0x10e
[<c13603c0>] do_page_fault+0x246/0x397
[<c136017a>] ? do_page_fault+0x0/0x397
[<c135e753>] error_code+0x6b/0x70
[<c136017a>] ? do_page_fault+0x0/0x397
[<c104f805>] ? __lock_acquire+0x91/0x12fd
[<c1050a62>] ? __lock_acquire+0x12ee/0x12fd
[<c1050a62>] ? __lock_acquire+0x12ee/0x12fd
[<c1050b2b>] lock_acquire+0xba/0xdd
[<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2]
[<c135d4fe>] down_write+0x2a/0x46
[<d0d17d3f>] ? nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2]
[<d0d17d3f>] nilfs_detach_segment_constructor+0x2f/0x2fa [nilfs2]
[<c104ea2c>] ? mark_held_locks+0x43/0x5b
[<c104ecb1>] ? trace_hardirqs_on_caller+0x10b/0x133
[<c104ece4>] ? trace_hardirqs_on+0xb/0xd
[<d0d09ac1>] nilfs_put_super+0x2f/0xca [nilfs2]
[<c10b3352>] generic_shutdown_super+0x49/0xb8
[<c10b33de>] kill_block_super+0x1d/0x31
[<c10e6599>] ? vfs_quota_off+0x0/0x12
[<c10b398f>] deactivate_super+0x57/0x6c
[<c10c4bc3>] mntput_no_expire+0x8c/0xb4
[<c10c5094>] sys_umount+0x27f/0x2a4
[<c10c50c6>] sys_oldumount+0xd/0xf
[<c10031a4>] sysenter_do_call+0x12/0x38
...
This turns out to be a bug brought by an -rc1 patch ("nilfs2: simplify
remaining sget() use").
In the patch, a new "put resource" function, nilfs_put_sbinfo()
was introduced to delay freeing nilfs_sb_info struct.
But the nilfs_put_sbinfo() mistakenly used atomic_dec_and_test()
function to check the reference count, and it caused the nilfs_sb_info
was freed when user mounted a snapshot twice.
This bug also suggests there was unseen memory leak in usual mount
/umount operations for nilfs.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
pushd tools/perf/Documentation
make html
popd
is failing for me...
ASCIIDOC perf-annotate.html
ERROR: unsafe: include file: /etc/asciidoc/./stylesheets/xhtml11.css
ERROR: unsafe: include file:
/etc/asciidoc/./stylesheets/xhtml11-manpage.css
ERROR: unsafe: include file:
/etc/asciidoc/./stylesheets/xhtml11-quirks.css
make: *** [perf-annotate.html] Error 1
Apparently asciidoc "unsafe" is the default mode of operation
in practice.
https://bugzilla.redhat.com/show_bug.cgi?id=506953
Works tidily now.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090818164125.GM25206@bombadil.infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 0e83815be7 changed the
section the initial_code variable gets allocated in, in an
attempt to address a section conflict warning. This, however
created a new section conflict when building without
HOTPLUG_CPU. The apparently only (reasonable) way to address
this is to always use __REFDATA.
Once at it, also fix a second section mismatch when not using
HOTPLUG_CPU.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4A8AE7CD020000780001054B@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The wake_up_process() of the new irq thread in __setup_irq() is too
early as the irqaction is not yet fully initialized especially
action->irq is not yet set. The interrupt thread might dereference the
wrong irq descriptor.
Move the wakeup after the action is installed and action->irq has been
set.
Reported-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Buesch <mb@bu3sch.de>
Linus reported this perf annotate segfault:
[torvalds@nehalem git]$ perf annotate unmap_vmas
Segmentation fault
#0 map__clone (self=<value optimized out>) at builtin-annotate.c:236
#1 thread__fork (self=<value optimized out>) at builtin-annotate.c:372
The bug here was that builtin-annotate.c was a copy of
builtin-report.c and a threading related fix to builtin-report.c
didnt get propagated to builtin-annotate.c ...
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
PARISC does not build:
/home/mingo/tip/kernel/perf_counter.c: In function 'perf_counter_index':
/home/mingo/tip/kernel/perf_counter.c:2016: error: 'PERF_COUNTER_INDEX_OFFSET' undeclared (first use in this function)
/home/mingo/tip/kernel/perf_counter.c:2016: error: (Each undeclared identifier is reported only once
/home/mingo/tip/kernel/perf_counter.c:2016: error: for each function it appears in.)
As PERF_COUNTER_INDEX_OFFSET is not defined.
Now, we could define it in the architecture - but lets also provide
a core default of 0 (which happens to be what all but one
architecture uses at the moment).
Architectures that need a different index offset should set this
value in their asm/perf_counter.h files.
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
For noMMU system when you use larger rootfs image
there is problem with using _end label because
we increase klimit but in memory initialization
we use still _end which is wrong. Larger mtd rootfs
was rewritten by init_bootmem_node.
MMU kernel use static initialization where klimit
is setup to _end. There is no any other hanling
with klimit.
Signed-off-by: Michal Simek <monstr@monstr.eu>
This code path doesn't test any returned pointers for NULL, leading to a bad
kernel page fault if there's no timer/intc found.
Slightly better is to BUG(), but even better still would be a printk beforehand.
Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
'ns_cno' of structure 'the_nilfs' must be protected from segment
writer, in other words, the caller of nilfs_get_checkpoint should hold
read lock for nilfs->ns_segctor_sem. This patch adds the lock/unlock
operations in nilfs_attach_checkpoint() when calling
nilfs_cpfile_get_checkpoint().
Signed-off-by: Zhang Qiang <zhangqiang.buaa@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This adds support for tracing callchains for powerpc, both 32-bit
and 64-bit, and both in the kernel and userspace, from PMU interrupt
context.
The first three entries stored for each callchain are the NIP (next
instruction pointer), LR (link register), and the contents of the LR
save area in the second stack frame (the first is ignored because the
ABI convention on powerpc is that functions save their return address
in their caller's stack frame). Because leaf functions don't have to
save their return address (LR value) and don't have to establish a
stack frame, it's possible for either or both of LR and the second
stack frame's LR save area to have valid return addresses in them.
This is basically impossible to disambiguate without either reading
the code or looking at auxiliary information such as CFI tables.
Since we don't want to do either of those things at interrupt time,
we store both LR and the second stack frame's LR save area.
Once we get past the second stack frame, there is no ambiguity; all
return addresses we get are reliable.
For kernel traces, we check whether they are valid kernel instruction
addresses and store zero instead if they are not (rather than
omitting them, which would make it impossible for userspace to know
which was which). We also store zero instead of the second stack
frame's LR save area value if it is the same as LR.
For kernel traces, we check for interrupt frames, and for user traces,
we check for signal frames. In each case, since we're starting a new
trace, we store a PERF_CONTEXT_KERNEL/USER marker so that userspace
knows that the next three entries are NIP, LR and the second stack frame
for the interrupted context.
We read user memory with __get_user_inatomic. On 64-bit, if this
PMU interrupt occurred while interrupts are soft-disabled, and
there is no MMU hash table entry for the page, we will get an
-EFAULT return from __get_user_inatomic even if there is a valid
Linux PTE for the page, since hash_page isn't reentrant. Thus we
have code here to read the Linux PTE and access the page via the
kernel linear mapping. Since 64-bit doesn't use (or need) highmem
there is no need to do kmap_atomic. On 32-bit, we don't do soft
interrupt disabling, so this complication doesn't occur and there
is no need to fall back to reading the Linux PTE, since hash_page
(or the TLB miss handler) will get called automatically if necessary.
Note that we cannot get PMU interrupts in the interval during
context switch between switch_mm (which switches the user address
space) and switch_to (which actually changes current to the new
process). On 64-bit this is because interrupts are hard-disabled
in switch_mm and stay hard-disabled until they are soft-enabled
later, after switch_to has returned. So there is no possibility
of trying to do a user stack trace when the user address space is
not current's address space.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This provides a mechanism to allow the perf_counters code to access
user memory in a PMU interrupt routine. Such an access can cause
various kinds of interrupt: SLB miss, MMU hash table miss, segment
table miss, or TLB miss, depending on the processor. This commit
only deals with 64-bit classic/server processors, which use an MMU
hash table. 32-bit processors are already able to access user memory
at interrupt time. Since we don't soft-disable on 32-bit, we avoid
the possibility of reentering hash_page or the TLB miss handlers,
since they run with interrupts disabled.
On 64-bit processors, an SLB miss interrupt on a user address will
update the slb_cache and slb_cache_ptr fields in the paca. This is
OK except in the case where a PMU interrupt occurs in switch_slb,
which also accesses those fields. To prevent this, we hard-disable
interrupts in switch_slb. Interrupts are already soft-disabled at
this point, and will get hard-enabled when they get soft-enabled
later.
This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice,
and to make sure that it clears the slb_cache_ptr when called from
other callers than switch_slb, the existing routine is renamed to
__slb_flush_and_rebolt, which is called by switch_slb and the new
version of slb_flush_and_rebolt.
Similarly, switch_stab (used on POWER3 and RS64 processors) gets a
hard_irq_disable() to protect the per-cpu variables used there and
in ste_allocate.
If a MMU hashtable miss interrupt occurs, normally we would call
hash_page to look up the Linux PTE for the address and create a HPTE.
However, hash_page is fairly complex and takes some locks, so to
avoid the possibility of deadlock, we check the preemption count
to see if we are in a (pseudo-)NMI handler, and if so, we don't call
hash_page but instead treat it like a bad access that will get
reported up through the exception table mechanism. An interrupt
whose handler runs even though the interrupt occurred when
soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI
handler, which should use nmi_enter()/nmi_exit() rather than
irq_enter()/irq_exit().
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On 32-bit systems with 64-bit PTEs, the PTEs have to be written in two
32-bit halves. On SMP we write the higher-order half and then the
lower-order half, with a write barrier between the two halves, but on
UP there was no particular ordering of the writes to the two halves.
This extends the ordering that we already do on SMP to the UP case as
well. The reason is that with the perf_counter subsystem potentially
accessing user memory at interrupt time to get stack traces, we have
to be careful not to create an incorrect but apparently valid PTE even
on UP.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
In 5e140dfc1f "net: reorder struct Qdisc
for better SMP performance" the definition of struct gnet_stats_basic
changed incompatibly, as copies of this struct are shipped to
userland via netlink.
Restoring old behavior is not welcome, for performance reason.
Fix is to use a private structure for kernel, and
teach gnet_stats_copy_basic() to convert from kernel to user land,
using legacy structure (struct gnet_stats_basic)
Based on a report and initial patch from Michael Spang.
Reported-by: Michael Spang <mspang@csclub.uwaterloo.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The static variable used by nr_call_to_digi might result in corruption if
multiple threads are trying to usee a node or neighbour via ioctl. Fixed
by having the caller pass a structure in. This is safe because nr_add_node
rsp. nr_add_neigh will allocate a permanent structure, if needed.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recent commit c8c00a6915
changed the exit paths in do_md_stop and was not quite
careful enough. There is one path were 'err' now needs
to be cleared but it isn't.
So setting an array to readonly (with mdadm --readonly) will
work, but will incorrectly report and error: ENXIO.
Signed-off-by: NeilBrown <neilb@suse.de>
"echo noglobal-clock > trace_options" can be used to change trace
clock but "echo 0 > options/global-clock" can't. The flag toggling
will be silently accepted without actually changing the clock callback.
We can fix it by using set_tracer_flags() in
trace_options_core_write().
Changelog:
v1->v2: Simplified switch() after Li Zefan <lizf@cn.fujitsu.com>'s
suggestion
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
If we fail to mount the filesystem, we have to be careful not to dereference
uninitialized structures in ocfs2_kill_sb.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Max Vozeler reported:
> Bug 13877 - bogl-term broken with CONFIG_X86_PAT=y, works with =n
>
> strace of bogl-term:
> 814 mmap2(NULL, 65536, PROT_READ|PROT_WRITE, MAP_SHARED, 4, 0)
> = -1 EAGAIN (Resource temporarily unavailable)
> 814 write(2, "bogl: mmaping /dev/fb0: Resource temporarily unavailable\n",
> 57) = 57
PAT code maps the ISA memory range as WB in the PAT attribute, so that
fixed range MTRR registers define the actual memory type (UC/WC/WT etc).
But the upper level is_new_memtype_allowed() API checks are failing,
as the request here is for UC and the return tracked type is WB (Tracked type is
WB as MTRR type for this legacy range potentially will be different for each
4k page).
Fix is_new_memtype_allowed() by always succeeding the ISA address range
checks, as the null PAT (WB) and def MTRR fixed range register settings
satisfy the memory type needs of the applications that map the ISA address
range.
Reported-and-Tested-by: Max Vozeler <xam@debian.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
security: define round_hint_to_min in !CONFIG_SECURITY
Security/SELinux: seperate lsm specific mmap_min_addr
SELinux: call cap_file_mmap in selinux_file_mmap
Capabilities: move cap_file_mmap to commoncap.c
The inotify_add_watch man page specifies that inotify_add_watch() will
return a non-negative integer. However, historically the inotify
watches started at 1, not at 0.
Turns out that the inotifywait program provided by the inotify-tools
package doesn't properly handle a 0 watch descriptor. In 7e790dd5 we
changed from starting at 1 to starting at 0. This patch starts at 1,
just like in previous kernels, but also just like in previous kernels
it's possible for it to wrap back to 0. This preserves the kernel
functionality exactly like it was before the patch (neither method broke
the spec)
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In f44aebcc the tail drop logic of events with no file backing
(q_overflow and in_ignored) was reversed so IN_IGNORED events would
never be tail dropped. This now means that Q_OVERFLOW events are NOT
tail dropped. The fix is to not tail drop IN_IGNORED, but to tail drop
Q_OVERFLOW.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
inotify decides if private data it passed to get added to an event was
used by checking list_empty(). But it's possible that the event may
have been dequeued and the private event removed so it would look empty.
The fix is to use the return code from fsnotify_add_notify_event rather
than looking at the list.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ocfs2_do_truncate, we forget to release last_eb_bh which
will cause memleak. So call brelse in the end.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
ocfs2_read_virt_blocks() does BUG when we try to read a block from a file
beyond its end. Since this can happen due to filesystem corruption, it
is not really an appropriate answer. Make ocfs2_read_quota_block() check
the condition and handle it by calling ocfs2_error() and returning EIO.
[ Modified to print ip_blkno in the error - Joel ]
Reported-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The key todo lock can be taken from different locks
that require it to be _bh to avoid lock inversion
due to (soft)irqs.
This should fix the two problems reported by Bob and
Gabor:
http://mid.gmane.org/20090619113049.GB18956@hash.localnethttp://mid.gmane.org/4A3FA376.8020307@openwrt.org
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Bob Copeland <me@bobcopeland.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch fixes warnings like this:
CC fs/proc/meminfo.o
In file included from /work/linux/include/linux/mmzone.h:20,
from /work/linux/include/linux/gfp.h:4,
from /work/linux/include/linux/mm.h:8,
from /work/linux/fs/proc/meminfo.c:5:
/work/linux/arch/mips/include/asm/page.h:36:1: warning: "HPAGE_SIZE" redefined
In file included from /work/linux/fs/proc/meminfo.c:2:
/work/linux/include/linux/hugetlb.h:107:1: warning: this is the location of the previous definition
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
An older test-box started hanging at the following point during
bootup:
[ 0.022996] Mount-cache hash table entries: 512
[ 0.024996] Initializing cgroup subsys debug
[ 0.025996] Initializing cgroup subsys cpuacct
[ 0.026995] Initializing cgroup subsys devices
[ 0.027995] Initializing cgroup subsys freezer
[ 0.028995] mce: CPU supports 5 MCE banks
I've bisected it down to commit 4efc0670 ("x86, mce: use 64bit
machine check code on 32bit"), which utilizes the MCE code on
32-bit systems too.
The problem is caused by this detail in my config:
# CONFIG_CPU_SUP_INTEL is not set
This disables the quirks in mce_cpu_quirks() but still enables
MCE support - which then hangs due to the missing quirk
workaround needed on this CPU:
if (c->x86 == 6 && c->x86_model < 0x1A && banks > 0)
mce_banks[0].init = 0;
The safe solution is to not initialize MCEs if we dont know on
what CPU we are running (or if that CPU's support code got
disabled in the config).
Also be a bit more defensive on 32-bit systems: dont do a
boot-time dump of pending MCEs not just on the specific system
that we found a problem with (Pentium-M), but earlier ones as
well.
Now this problem is probably not common and disabling CPU
support is rare - but still being more defensive in something
we turned on for a wide range of CPUs is prudent.
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
LKML-Reference: Message-ID: <4A88E3E4.40506@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
/proc/timer_list and /proc/slabinfo are not supposed to be
written, so there should be no write permissions on it.
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: linux-mm@kvack.org
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <20090817094525.6355.88682.sendpatchset@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In general, code in perf_counter.c that is called through an
IPI checks, for per-task counters, that the counter's task is
still the current task. This is to handle the race condition
where the cpu switches from the task we want to another task in
the interval between sending the IPI and the IPI arriving and
being handled on the target CPU.
For some reason, __perf_counter_read is missing this check, yet
there is no reason why the race condition can't occur. This
adds a check that the current task is the one we want. If it
isn't, we just return. In that case the counter->count value
should be up to date, since it will have been updated when the
counter was scheduled out, which must have happened since the
IPI was sent.
I don't have an example of an actual failure due to this race,
but it seems obvious that it could occur and we need to guard
against it.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19076.63614.277861.368125@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename it to examples.txt to avoid the perf-*.txt pattern in
the Makefile, otherwise 'make doc' fails because
perf-examples.txt is not formatted to be a man page:
ERROR: perf-examples.txt: line 1: manpage document title is mandatory
Signed-off-by: Carlos R. Mafra <crmafra@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On my legacy Pentium M laptop (Acer Extensa 2900) I get bogus MCE on a cold
boot with CONFIG_X86_NEW_MCE enabled, i.e. (after decoding it with mcelog):
MCE 0
HARDWARE ERROR. This is *NOT* a software problem!
Please contact your hardware vendor
CPU 0 BANK 1 MCG status:
MCi status:
Error overflow
Uncorrected error
Error enabled
Processor context corrupt
MCA: Data CACHE Level-1 UNKNOWN Error
STATUS f200000000000195 MCGSTATUS 0
[ The other STATUS values observed: f2000000000001b5 (... UNKNOWN error)
and f200000000000115 (... READ Error).
To verify that this is not a CONFIG_X86_NEW_MCE bug I also modified
the CONFIG_X86_OLD_MCE code (which doesn't log any MCEs) to dump
content of STATUS MSR before it is cleared during initialization. ]
Since the bogus MCE results in a kernel taint (which in turn disables
lockdep support) don't log boot MCEs on Pentium M (model == 13) CPUs
by default ("mce=bootlog" boot parameter can be be used to get the old
behavior).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The locking in xfs_iget_cache_hit currently has numerous problems:
- we clear the reclaim tag without i_flags_lock which protects
modifications to it
- we call inode_init_always which can sleep with pag_ici_lock
held (this is oss.sgi.com BZ #819)
- we acquire and drop i_flags_lock a lot and thus provide no
consistency between the various flags we set/clear under it
This patch fixes all that with a major revamp of the locking in
the function. The new version acquires i_flags_lock early and
only drops it once we need to call into inode_init_always or before
calling xfs_ilock.
This patch fixes a bug seen in the wild where we race modifying the
reclaim tag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Fix the header files to define round_hint_to_min() and to define
mmap_min_addr_handler() in the !CONFIG_SECURITY case.
Built and tested with !CONFIG_SECURITY
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
