Oleg Nesterov [Wed, 20 Mar 2013 04:06:47 +0000 (15:06 +1100)]
poweroff: change orderly_poweroff() to use schedule_work()
David said:
Commit 6c0c0d4d108 ("poweroff: fix bug in orderly_poweroff()")
apparently fixes one bug in orderly_poweroff(), but introduces
another. The comments on orderly_poweroff() claim it can be called
from any context - and indeed we call it from interrupt context in
arch/powerpc/platforms/pseries/ras.c for example. But since that
commit this is no longer safe, since call_usermodehelper_fns() is not
safe in interrupt context without the UMH_NO_WAIT option.
orderly_poweroff() can be used from any context but UMH_WAIT_EXEC is
sleepable. Move the "force" logic into __orderly_poweroff() and change
orderly_poweroff() to use the global poweroff_work which simply calls
__orderly_poweroff().
While at it, remove the unneeded "int argc" and change argv_split() to use
GFP_KERNEL.
We use the global "bool poweroff_force" to pass the argument, this can
obviously affect the previous request if it is pending/running. So we
only allow the "false => true" transition assuming that the pending "true"
should succeed anyway. If schedule_work() fails after that we know that
work->func() was not called yet, it must see the new value.
This means that orderly_poweroff() becomes async even if we do not run the
command and always succeeds, schedule_work() can only fail if the work is
already pending. We can export __orderly_poweroff() and change the
non-atomic callers which want the old semantics.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: David Gibson <david@gibson.dropbear.id.au> Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Feng Hong <hongfeng@marvell.com> Cc: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wanpeng Li [Wed, 20 Mar 2013 04:06:46 +0000 (15:06 +1100)]
mm/hugetlb: fix total hugetlbfs pages count when using memory overcommit accouting
hugetlb_total_pages is used for overcommit calculations but the current
implementation considers only the default hugetlb page size (which is
either the first defined hugepage size or the one specified by
default_hugepagesz kernel boot parameter).
If the system is configured for more than one hugepage size, which is
possible since a137e1cc ("hugetlbfs: per mount huge page sizes") then the
overcommit estimation done by __vm_enough_memory() (resp. shown by
meminfo_proc_show) is not precise - there is an impression of more
available/allowed memory. This can lead to an unexpected ENOMEM/EFAULT
resp. SIGSEGV when memory is accounted.
Testcase:
boot: hugepagesz=1G hugepages=1
the default overcommit ratio is 50
before patch:
egrep 'CommitLimit' /proc/meminfo
CommitLimit: 55434168 kB
after patch:
egrep 'CommitLimit' /proc/meminfo
CommitLimit: 54909880 kB
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> [3.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
wake_up_klogd() is useless when CONFIG_PRINTK=n because neither printk()
nor printk_sched() are in use and there are actually no waiter on log_wait
waitqueue. It should be a stub in this case for users like
bust_spinlocks().
Otherwise this results in this warning when CONFIG_PRINTK=n
and CONFIG_IRQ_WORK=n:
kernel/built-in.o In function `wake_up_klogd':
(.text.wake_up_klogd+0xb4): undefined reference to `irq_work_queue'
To fix this, provide an off-case for wake_up_klogd() when CONFIG_PRINTK=n.
There is much more from console_unlock() and other console related code in
printk.c that should be moved under CONFIG_PRINTK. But for now, focus on
a minimal fix as we passed the merged window already.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reported-by: James Hogan <james.hogan@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log