Andrea Righi 9e4a5bda89 mm: prevent divide error for small values of vm_dirty_bytes ... Avoid setting less than two pages for vm_dirty_bytes: this is necessary to avoid potential division by 0 (like the following) in get_dirty_limits(). [ 49.951610] divide error: 0000 [#1] PREEMPT SMP [ 49.952195] last sysfs file: /sys/devices/pci0000:00/0000:00:01.1/host0/target0:0:0/0:0:0:0/block/sda/uevent [ 49.952195] CPU 1 [ 49.952195] Modules linked in: pcspkr [ 49.952195] Pid: 3064, comm: dd Not tainted 2.6.30-rc3 #1 [ 49.952195] RIP: 0010:[<ffffffff802d39a9>] [<ffffffff802d39a9>] get_dirty_limits+0xe9/0x2c0 [ 49.952195] RSP: 0018:ffff88001de03a98 EFLAGS: 00010202 [ 49.952195] RAX: 00000000000000c0 RBX: ffff88001de03b80 RCX: 28f5c28f5c28f5c3 [ 49.952195] RDX: 0000000000000000 RSI: 00000000000000c0 RDI: 0000000000000000 [ 49.952195] RBP: ffff88001de03ae8 R08: 0000000000000000 R09: 0000000000000000 [ 49.952195] R10: ffff88001ddda9a0 R11: 0000000000000001 R12: 0000000000000001 [ 49.952195] R13: ffff88001fbc8218 R14: ffff88001de03b70 R15: ffff88001de03b78 [ 49.952195] FS: 00007fe9a435b6f0(0000) GS:ffff8800025d9000(0000) knlGS:0000000000000000 [ 49.952195] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.952195] CR2: 00007fe9a39ab000 CR3: 000000001de38000 CR4: 00000000000006e0 [ 49.952195] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 49.952195] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 49.952195] Process dd (pid: 3064, threadinfo ffff88001de02000, task ffff88001ddda250) [ 49.952195] Stack: [ 49.952195] ffff88001fa0de00 ffff88001f2dbd70 ffff88001f9fe800 000080b900000000 [ 49.952195] 00000000000000c0 ffff8800027a6100 0000000000000400 ffff88001fbc8218 [ 49.952195] 0000000000000000 0000000000000600 ffff88001de03bb8 ffffffff802d3ed7 [ 49.952195] Call Trace: [ 49.952195] [<ffffffff802d3ed7>] balance_dirty_pages_ratelimited_nr+0x1d7/0x3f0 [ 49.952195] [<ffffffff80368f8e>] ? ext3_writeback_write_end+0x9e/0x120 [ 49.952195] [<ffffffff802cc7df>] generic_file_buffered_write+0x12f/0x330 [ 49.952195] [<ffffffff802cce8d>] __generic_file_aio_write_nolock+0x26d/0x460 [ 49.952195] [<ffffffff802cda32>] ? generic_file_aio_write+0x52/0xd0 [ 49.952195] [<ffffffff802cda49>] generic_file_aio_write+0x69/0xd0 [ 49.952195] [<ffffffff80365fa6>] ext3_file_write+0x26/0xc0 [ 49.952195] [<ffffffff803034d1>] do_sync_write+0xf1/0x140 [ 49.952195] [<ffffffff80290d1a>] ? get_lock_stats+0x2a/0x60 [ 49.952195] [<ffffffff80280730>] ? autoremove_wake_function+0x0/0x40 [ 49.952195] [<ffffffff8030411b>] vfs_write+0xcb/0x190 [ 49.952195] [<ffffffff803042d0>] sys_write+0x50/0x90 [ 49.952195] [<ffffffff8022ff6b>] system_call_fastpath+0x16/0x1b [ 49.952195] Code: 00 00 00 2b 05 09 1c 17 01 48 89 c6 49 0f af f4 48 c1 ee 02 48 89 f0 48 f7 e1 48 89 d6 31 d2 48 c1 ee 02 48 0f af 75 d0 48 89 f0 <48> f7 f7 41 8b 95 ac 01 00 00 48 89 c7 49 0f af d4 48 c1 ea 02 [ 49.952195] RIP [<ffffffff802d39a9>] get_dirty_limits+0xe9/0x2c0 [ 49.952195] RSP <ffff88001de03a98> [ 50.096523] ---[ end trace 008d7aa02f244d7b ]--- Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-05-02 15:36:10 -07:00
..
irq	x86, irq: Remove IRQ_DISABLED check in process context IRQ move	2009-04-14 15:21:13 +02:00
power	PM/Hibernate: Fix waiting for image device to appear on resume	2009-04-24 15:31:30 -07:00
time	clocksource: add enable() and disable() callbacks	2009-04-21 13:41:47 -07:00
trace	tracing: Fix branch tracer header	2009-04-14 02:30:36 +02:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.preempt	…
Makefile	…
acct.c	…
async.c	…
audit.c	…
audit.h	…
audit_tree.c	No need for crossing to mountpoint in audit_tag_tree()	2009-04-20 23:01:15 -04:00
auditfilter.c	…
auditsc.c	…
backtracetest.c	…
bounds.c	…
capability.c	…
cgroup.c	…
cgroup_debug.c	…
cgroup_freezer.c	…
compat.c	…
configs.c	…
cpu.c	…
cpuset.c	…
cred-internals.h	…
cred.c	…
delayacct.c	…
dma-coherent.c	…
dma.c	…
exec_domain.c	…
exit.c	Merge branch 'irq/threaded' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-07 14:07:52 -07:00
extable.c	…
fork.c	Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-09 10:35:30 -07:00
freezer.c	…
futex.c	…
futex_compat.c	…
hrtimer.c	…
hung_task.c	…
itimer.c	…
kallsyms.c	…
kexec.c	…
kfifo.c	…
kgdb.c	…
kmod.c	…
kprobes.c	kprobes: support per-kprobe disabling	2009-04-07 08:31:08 -07:00
ksysfs.c	…
kthread.c	kthread: move sched-realeted initialization from kthreadd context	2009-04-09 09:50:37 +09:30
latencytop.c	…
lockdep.c	lockdep: more robust lockdep_map init sequence	2009-04-17 18:00:00 +02:00
lockdep_internals.h	…
lockdep_proc.c	…
lockdep_states.h	…
marker.c	…
module.c	async: Fix module loading async-work regression	2009-04-11 12:44:49 -07:00
mutex-debug.c	…
mutex-debug.h	…
mutex.c	mutex: have non-spinning mutexes on s390 by default	2009-04-09 19:28:24 +02:00
mutex.h	…
notifier.c	…
ns_cgroup.c	…
nsproxy.c	…
panic.c	locking: clarify kernel-taint warning message	2009-04-23 09:36:52 +02:00
params.c	…
pid.c	…
pid_namespace.c	…
pm_qos_params.c	…
posix-cpu-timers.c	Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-09 10:37:28 -07:00
posix-timers.c	…
printk.c	…
profile.c	…
ptrace.c	ptrace: ptrace_attach: fix the usage of ->cred_exec_mutex	2009-04-27 20:30:51 +10:00
rcuclassic.c	…
rcupdate.c	RCU: Don't try and predeclare inline funcs as it upsets some versions of gcc	2009-04-15 13:55:14 -07:00
rcupreempt.c	…
rcupreempt_trace.c	…
rcutorture.c	…
rcutree.c	rcu: Make hierarchical RCU less IPI-happy	2009-04-14 11:31:50 +02:00
rcutree.h	…
rcutree_trace.c	rcu: Make hierarchical RCU less IPI-happy	2009-04-14 11:31:50 +02:00
relay.c	…
res_counter.c	…
resource.c	Remove 'recurse into child resources' logic from 'reserve_region_with_split()'	2009-04-18 21:44:24 -07:00
rtmutex-debug.c	…
rtmutex-debug.h	…
rtmutex-tester.c	…
rtmutex.c	…
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	…
sched.c	sched: Avoid printing sched_group::__cpu_power for default case	2009-04-17 00:46:05 +02:00
sched_clock.c	…
sched_cpupri.c	…
sched_cpupri.h	…
sched_debug.c	…
sched_fair.c	…
sched_features.h	…
sched_idletask.c	…
sched_rt.c	Merge commit 'v2.6.30-rc1' into sched/urgent	2009-04-08 17:26:00 +02:00
sched_stats.h	…
seccomp.c	…
semaphore.c	…
signal.c	…
slow-work.c	Delete slow-work timers properly	2009-04-24 07:47:59 -07:00
smp.c	…
softirq.c	kernel/softirq.c: fix sparse warning	2009-04-17 01:57:54 +02:00
softlockup.c	…
spinlock.c	…
srcu.c	…
stacktrace.c	…
stop_machine.c	…
sys.c	kernel/sys.c: clean up sys_shutdown exit path	2009-04-13 15:04:32 -07:00
sys_ni.c	…
sysctl.c	mm: prevent divide error for small values of vm_dirty_bytes	2009-05-02 15:36:10 -07:00
sysctl_check.c	…
taskstats.c	…
test_kprobes.c	…
time.c	…
timeconst.pl	…
timer.c	Merge branches 'core-fixes-for-linus', 'irq-fixes-for-linus' and 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-04-09 10:35:30 -07:00
tracepoint.c	…
tsacct.c	…
uid16.c	…
up.c	…
user.c	…
user_namespace.c	…
utsname.c	…
utsname_sysctl.c	…
wait.c	…
workqueue.c	work_on_cpu(): rewrite it to create a kernel thread on demand	2009-04-09 09:50:37 +09:30