I've been painstakingly debugging the issue with suspend to ram and
ftraced. The 2.6.28 code does not have this issue, but since the mcount
recording is not going to be in 27, this must be solved for the ftrace
daemon version.
The resume from suspend to ram would reboot because it was triple
faulting. Debugging further, I found that calling the mcount function
itself was not an issue, but it would fault when it incremented
preempt_count. preempt_count is on the tasks info structure that is on the
low memory address of the task's stack. For some reason, it could not
write to it. Resuming out of suspend to ram does quite a lot of funny
tricks to get to work, so it is not surprising at all that simply doing a
preempt_disable() would cause a fault.
Thanks to Rafael for suggesting to add a "while (1);" to find the place in
resuming that is causing the fault. I would place the loop somewhere in
the code, compile and reboot and see if it would either reboot (hit the
fault) or simply hang (hit the loop). Doing this over and over again, I
narrowed it down that it was happening in enable_nonboot_cpus.
At this point, I found that it is easier to simply disable tracing around
the suspend code, instead of searching for the particular function that
can not handle doing a preempt_disable.
This patch disables the tracer as it suspends and reenables it on resume.
I tested this patch on my Laptop, and it can resume fine with the patch.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'load_module()' is a complex function that contains all the ELF section
logic, and inlining it is utterly insane. But gcc will do it, simply
because there is only one call-site. As a result, all the stack space
that is allocated for all the work to load the module will still be
active when we actually call the module init sequence, and the deep call
chain makes stack overflows happen.
And stack overflows are really hard to debug, because they not only
corrupt random pages below the stack, but also corrupt the thread_info
structure that is allocated under the stack.
In this case, Alan Brunelle reported some crazy oopses at bootup, after
loading the processor module that ends up doing complex ACPI stuff and
has quite a deep callchain. This should fix it, and is the sane thing
to do regardless.
Cc: Alan D. Brunelle <Alan.Brunelle@hp.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch lets the files using linux/version.h match the files that
#include it.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after
I made an offlined cpu online, I found this cpu's event handler was
tick_handle_periodic, not tick_nohz_handler.
After debuging, I found this bug was caused by the wrong tick mode. the
tick mode is not changed to NOHZ_MODE_INACTIVE when the cpu is offline.
This patch fixes this bug.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix RCU's synchronize_rcu() so that it looks like a C function, enabling
it to be recognized as a function with kernel-doc annotation.
Warning(linux-2.6.26-git11//kernel/rcupdate.c:81): No description found for parameter 'synchronize_rcu'
Warning(linux-2.6.26-git11//kernel/rcupdate.c:81): No description found for parameter 'call_rcu'
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When user calls sys_setpriority(PRIO_PGRP ...) on a NPTL style multi-LWP
process, only the task leader of the process is affected, all other
sibling LWP threads didn't receive the setting. The problem was that the
iterator used in sys_setpriority() only iteartes over one task for each
process, ignoring all other sibling thread.
Introduce a new macro do_each_pid_thread / while_each_pid_thread to walk
each thread of a process. Convert 4 call sites in {set/get}priority and
ioprio_{set/get}.
Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I outwitted myself again in commit 2b2a1ff64a,
and broke the SA_NOCLDWAIT behavior so it leaks zombies. This fixes it.
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Roland McGrath <roland@redhat.com>
Since f82b217e35 lockdep can output spurious
warnings related to hwirqs due to hardirq_off shrinkage from int to bit-sized
flag. Guard it with double negation to fix the warning.
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: fix build if CONFIG_PROVE_LOCKING not defined
lockdep: use WARN() in kernel/lockdep.c
lockdep: spin_lock_nest_lock(), checkpatch fixes
lockdep: build fix
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: scale sysctl_sched_shares_ratelimit with nr_cpus
sched: fix rt-bandwidth hotplug race
sched: fix the race between walk_tg_tree and sched_create_group
If CONFIG_PROVE_LOCKING not defined, then no dependency information
is available.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
David reported that his Niagra spend a little too much time in
tg_shares_up(), which considering he has a large cpu count makes sense.
So scale the ratelimit value with the number of cpus like we do for
other controls as well.
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform. For example in kexec
jump, it is used for data and stack too.
[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
