Commit Graph

7497 Commits

Author SHA1 Message Date
Peter Oberparleiter
7bf99fb673 gcov: enable GCOV_PROFILE_ALL for x86_64
Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:

* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
  not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
  profiling causes segfaults during boot (incompatible context)

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:58 -07:00
Peter Oberparleiter
2521f2c228 gcov: add gcov profiling infrastructure
Enable the use of GCC's coverage testing tool gcov [1] with the Linux
kernel.  gcov may be useful for:

 * debugging (has this code been reached at all?)
 * test improvement (how do I change my test to cover these lines?)
 * minimizing kernel configurations (do I need this option if the
   associated code is never run?)

The profiling patch incorporates the following changes:

 * change kbuild to include profiling flags
 * provide functions needed by profiling code
 * present profiling data as files in debugfs

Note that on some architectures, enabling gcc's profiling option
"-fprofile-arcs" for the entire kernel may trigger compile/link/
run-time problems, some of which are caused by toolchain bugs and
others which require adjustment of architecture code.

For this reason profiling the entire kernel is initially restricted
to those architectures for which it is known to work without changes.
This restriction can be lifted once an architecture has been tested
and found compatible with gcc's profiling. Profiling of single files
or directories is still available on all platforms (see config help
text).

[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:57 -07:00
Peter Oberparleiter
b99b87f70c kernel: constructor support
Call constructors (gcc-generated initcall-like functions) during kernel
start and module load.  Constructors are e.g.  used for gcov data
initialization.

Disable constructor support for usermode Linux to prevent conflicts with
host glibc.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:57 -07:00
Alexey Dobriyan
90af90d7d3 nsproxy: extract create_nsproxy()
clone_nsproxy() does useless copying of old nsproxy -- every pointer will
be rewritten to new ns or to old ns.  Remove copying, rename
clone_nsproxy(), create_nsproxy() will be used by C/R code to create fresh
nsproxy on restart.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:56 -07:00
Alexey Dobriyan
4c2a7e72d5 utsns: extract creeate_uts_ns()
create_uts_ns() will be used by C/R to create fresh uts_ns.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:55 -07:00
Alexey Dobriyan
dca4a97960 pidns: rewrite copy_pid_ns()
copy_pid_ns() is a perfect example of a case where unwinding leads to more
code and makes it less clear.  Watch the diffstat.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:55 -07:00
Alexey Dobriyan
ed469a63c3 pidns: make create_pid_namespace() accept parent pidns
create_pid_namespace() creates everything, but caller has to assign parent
pidns by hand, which is unnatural.  At the moment of call new ->level has
to be taken from somewhere and parent pidns is already available.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:55 -07:00
Christoph Hellwig
17f98dcf60 pids: clean up find_task_by_pid variants
find_task_by_pid_type_ns is only used to implement find_task_by_vpid and
find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument.
So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use
find_task_by_pid_ns to implement find_task_by_vpid.

While we're at it also remove the exports for find_task_by_pid_ns and
find_task_by_vpid - we don't have any modular callers left as the only
modular caller of he old pre pid namespace find_task_by_pid (gfs2) was
switched to pid_task which operates on a struct pid pointer instead of a
pid_t.  Given the confusion about pid_t values vs namespace that's
generally the better option anyway and I think we're better of restricting
modules to do it that way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:55 -07:00
Sukanto Ghosh
7338f29984 sysctl.c: remove unused variable
Remoce the unused variable 'val' from __do_proc_dointvec()

The integer has been declared and used as 'val = -val' and there is no
reference to it anywhere.

Signed-off-by: Sukanto Ghosh <sukanto.cse.iitb@gmail.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Sukanto Ghosh <sukanto.cse.iitb@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:54 -07:00
Oleg Nesterov
371cbb387e kthreads: simplify migration_thread() exit path
Now that kthread_stop() can be used even if the task has already exited,
we can kill the "wait_to_die:" loop in migration_thread().  But we must
pin rq->migration_thread after creation.

Actually, I don't think CPU_UP_CANCELED or CPU_DEAD should wait for
->migration_thread exit.  Perhaps we can simplify this code a bit more.
migration_call() can set ->should_stop and forget about this thread.  But
we need a new helper in kthred.c for that.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:54 -07:00
Oleg Nesterov
63706172f3 kthreads: rework kthread_stop()
Based on Eric's patch which in turn was based on my patch.

kthread_stop() has the nasty problems:

- it runs unpredictably long with the global semaphore held.

- it deadlocks if kthread itself does kthread_stop() before it obeys
  the kthread_should_stop() request.

- it is not useable if kthread exits on its own, see for example the
  ugly "wait_to_die:" hack in migration_thread()

- it is not possible to just tell kthread it should stop, we must always
  wait for its exit.

With this patch kthread() allocates all neccesary data (struct kthread) on
its own stack, globals kthread_stop_xxx are deleted.  ->vfork_done is used
as a pointer into "struct kthread", this means kthread_stop() can easily
wait for kthread's exit.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:54 -07:00
Oleg Nesterov
cdd140bdd6 kthreads: simplify the startup synchronization
We use two completions two create the kernel thread, this is a bit ugly.
kthread() wakes up create_kthread() via ->started, then create_kthread()
wakes up the caller kthread_create() via ->done.  But kthread() does not
need to wait for kthread(), it can just return.  Instead kthread() itself
can wake up the caller of kthread_create().

Kill kthread_create_info->started, ->done is enough.  This improves the
scalability a bit and sijmplifies the code.

The only problem if kernel_thread() fails, in that case create_kthread()
must do complete(&create->done).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:53 -07:00
Richard Kennedy
e1eb1ebcca mm: exit.c reorder wait_opts to remove padding on 64 bit builds
Reorder struct wait_opts to remove 8 bytes of alignment padding on 64 bit
builds.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:53 -07:00
Oleg Nesterov
f95d39d10f do_wait: fix the theoretical race with stop/trace/cont
do_wait:

	current->state = TASK_INTERRUPTIBLE;

	read_lock(&tasklist_lock);
	... search for the task to reap ...

In theory, the ->state changing can leak into the critical section.  Since
the child can change its status under read_lock(tasklist) in parallel
(finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent()
sees us in TASK_RUNNING state.  Add the barrier.

Also, use __set_current_state() to set TASK_RUNNING.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:53 -07:00
Oleg Nesterov
a3f6dfb729 do_wait: kill the old BUG_ON, use while_each_thread()
do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a
raher obsolete check.  At least, I don't think do_wait() is the best place
to verify that all threads have the same ->signal.  Remove it.

Also, change the code to use while_each_thread().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:53 -07:00
Oleg Nesterov
64a16caf5e do_wait: simplify retval/tsk_result/notask_error mess
Now that we don't pass &retval down to other helpers we can simplify
the code more.

- kill tsk_result, just use retval

- add the "notask" label right after the main loop, and
  s/got end/goto notask/ after the fastpath pid check.

  This way we don't need to initialize retval before this
  check and the code becomes a bit more clean, if this pid
  has no attached tasks we should just skip the list search.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:53 -07:00
Oleg Nesterov
9e8ae01d1c introduce "struct wait_opts" to simplify do_wait() patches
Introduce "struct wait_opts" which holds the parameters for misc helpers
in do_wait() pathes.

This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho
makes the code much more readable.

This patch temporary uglifies rusage/siginfo code a little bit, will be
addressed by further cleanups.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
47918025ef shift "ptrace implies WUNTRACED" from ptrace_do_wait() to wait_task_stopped()
No functional changes, preparation for the next patch.

ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which
should always accept the stopped tracee, even if do_wait() was called
without WUNTRACED.

Change wait_task_stopped() to check "ptrace || WUNTRACED" instead.  This
makes the code more explicit, and "int options" argument becomes const in
do_wait() pathes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
72a1de39f8 copy_process(): remove the unneeded clear_tsk_thread_flag(TIF_SIGPENDING)
The forked child can have TIF_SIGPENDING if it was copied from parent's
ti->flags.  But this is harmless and actually almost never happens,
because copy_process() can't succeed if signal_pending() == T.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
77d1ef7956 wait_task_zombie: do not use thread_group_cputime()
There is no reason for thread_group_cputime() in wait_task_zombie(), there
must be no other threads.

This call was previously needed to collect the per-cpu data which we do
not have any longer.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
e49612544c ptrace: don't take tasklist to get/set ->last_siginfo
Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock.  Perhaps it makes sense to make a single helper
with "bool rw" argument.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
d92656633b ptrace: do_notify_parent_cldstop: fix the wrong ->nsproxy usage
If the non-traced sub-thread calls do_notify_parent_cldstop(), we send the
notification to group_leader->real_parent and we report group_leader's
pid.

But, if group_leader is traced we use the wrong ->parent->nsproxy->pid_ns,
the tracer and parent can live in different namespaces.  Change the code
to use "parent" instead of tsk->parent.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:52 -07:00
Oleg Nesterov
d1e98f429a ptrace: wait_task_zombie: s/->parent/->real_parent/
Change wait_task_zombie() to use ->real_parent instead of ->parent.  We
could even use current afaics, but ->real_parent is more clean.

We know that the child is not ptrace_reparented() and thus they are equal.
 But we should avoid using task_struct->parent, we are going to remove it.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
8053bdd5ce ptrace_get_task_struct: s/tasklist/rcu/, make it static
- Use rcu_read_lock() instead of tasklist_lock to find/get the task
  in ptrace_get_task_struct().

- Make it static, it has no callers outside of ptrace.c.

- The comment doesn't match the reality, this helper does not do
  any checks. Beacuse it is really trivial and static I removed the
  whole comment.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
4b105cbbaf ptrace: do not use task_lock() for attach
Remove the "Nasty, nasty" lock dance in ptrace_attach()/ptrace_traceme() -
from now task_lock() has nothing to do with ptrace at all.

With the recent changes nobody uses task_lock() to serialize with ptrace,
but in fact it was never needed and it was never used consistently.

However ptrace_attach() calls __ptrace_may_access() and needs task_lock()
to pin task->mm for get_dumpable().  But we can call __ptrace_may_access()
before we take tasklist_lock, ->cred_exec_mutex protects us against
do_execve() path which can change creds and MMF_DUMP* flags.

(ugly, but we can't use ptrace_may_access() because it hides the error
code, so we have to take task_lock() and use __ptrace_may_access()).

NOTE: this change assumes that LSM hooks, security_ptrace_may_access() and
security_ptrace_traceme(), can be called without task_lock() held.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
f2f0b00ad6 ptrace: cleanup check/set of PT_PTRACED during attach
ptrace_attach() and ptrace_traceme() are the last functions which look as
if the untraced task can have task->ptrace != 0, this must not be
possible.  Change the code to just check ->ptrace != 0 and s/|=/=/ to set
PT_PTRACED.

Also, a couple of trivial whitespace cleanups in ptrace_attach().

And move ptrace_traceme() up near ptrace_attach() to keep them close to
each other.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
b79b7ba93d ptrace: ptrace_attach: check PF_KTHREAD + exit_state instead of ->mm
- Add PF_KTHREAD check to prevent attaching to the kernel thread
  with a borrowed ->mm.

  With or without this change we can race with daemonize() which
  can set PF_KTHREAD or clear ->mm after ptrace_attach() does the
  check, but this doesn't matter because reparent_to_kthreadd()
  does ptrace_unlink().

- Kill "!task->mm" check. We don't really care about ->mm != NULL,
  and the task can call exit_mm() right after we drop task_lock().
  What we need is to make sure we can't attach after exit_notify(),
  check task->exit_state != 0 instead.

Also, move the "already traced" check down for cosmetic reasons.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
5cb1144689 ptrace: do not use task->ptrace directly in core kernel
No functional changes.

- Nobody except ptrace.c & co should use ptrace flags directly, we have
  task_ptrace() for that.

- No need to specially check PT_PTRACED, we must not have other PT_ bits
  set without PT_PTRACED. And no need to know this flag exists.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:51 -07:00
Oleg Nesterov
dea33cfd99 ptrace: mm_need_new_owner: use ->real_parent to search in the siblings
"Search in the siblings" should use ->real_parent, not ->parent.  If the
task is traced then ->parent == tracer, while the task's parent is always
->real_parent.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:49 -07:00
Oleg Nesterov
87245135d5 allow_signal: kill the bogus ->mm check, add a note about CLONE_SIGHAND
allow_signal() checks ->mm == NULL.  Not sure why.  Perhaps to make sure
current is the kernel thread.  But this helper must not be used unless we
are the kernel thread, kill this check.

Also, document the fact that the CLONE_SIGHAND kthread must not use
allow_signal(), unless the caller really wants to change the parent's
->sighand->action as well.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:48 -07:00
Daisuke Nishimura
c5b947b288 memcg: add interface to reset limits
We don't have an interface to reset mem.limit or memsw.limit now.

This patch allows to reset mem.limit or memsw.limit when they are being
set to -1.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:48 -07:00
Li Zefan
f9ab5b5b0f cgroups: forbid noprefix if mounting more than just cpuset subsystem
The 'noprefix' option was introduced for backwards-compatibility of
cpuset, but actually it can be used when mounting other subsystems.

This results in possibility of name collision, and now the collision can
really happen, because we have 'stat' file in both memory and cpuacct
subsystem:

	# mount -t cgroup -o noprefix,memory,cpuacct xxx /mnt

Cgroup will happily mount the 2 subsystems, but only 'stat' file of memory
subsys can be seen.

We don't want users to use nopreifx, and also want to avoid name
collision, so we change to allow noprefix only if mounting just the cpuset
subsystem.

[akpm@linux-foundation.org: fix shift for cpuset_subsys_id >= 32]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:46 -07:00
Keika Kobayashi
aa0ce5bbc2 softirq: introduce statistics for softirq
Statistics for softirq doesn't exist.
It will be helpful like statistics for interrupts.
This patch introduces counting the number of softirq,
which will be exported in /proc/softirqs.

When softirq handler consumes much CPU time,
/proc/stat is like the following.

$ while :; do  cat /proc/stat | head -n1 ; sleep 10 ; done
cpu  88 0 408 739665 583 28 2 0 0
cpu  450 0 1090 740970 594 28 1294 0 0
                              ^^^^
                             softirq

In such a situation,
/proc/softirqs shows us which softirq handler is invoked.
We can see the increase rate of softirqs.

<before>
$ cat /proc/softirqs
                CPU0       CPU1       CPU2       CPU3
HI                 0          0          0          0
TIMER         462850     462805     462782     462718
NET_TX             0          0          0        365
NET_RX          2472          2          2         40
BLOCK              0          0        381       1164
TASKLET            0          0          0        224
SCHED         462654     462689     462698     462427
RCU             3046       2423       3367       3173

<after>
$ cat /proc/softirqs
                CPU0       CPU1       CPU2       CPU3
HI                 0          0          0          0
TIMER         463361     465077     465056     464991
NET_TX            53          0          1        365
NET_RX          3757          2          2         40
BLOCK              0          0        398       1170
TASKLET            0          0          0        224
SCHED         463074     464318     464612     463330
RCU             3505       2948       3947       3673

When CPU TIME of softirq is high,
the rates of increase is the following.
  TIMER  : 220/sec     : CPU1-3
  NET_TX : 5/sec       : CPU0
  NET_RX : 120/sec     : CPU0
  SCHED  : 40-200/sec  : all CPU
  RCU    : 45-58/sec   : all CPU

The rates of increase in an idle mode is the following.
  TIMER  : 250/sec
  SCHED  : 250/sec
  RCU    : 2/sec

It seems many softirqs for receiving packets and rcu are invoked.  This
gives us help for checking system.

Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Reviewed-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:40 -07:00
Linus Torvalds
b7c142dbf1 Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: start using hrtimers
  hrtimer: export ktime_add_safe
  UBIFS: do not forget to register BDI device
  UBIFS: allow sync option in rootflags
  UBIFS: remove dead code
  UBIFS: use anonymous device
  UBIFS: return proper error code if the compr is not present
  UBIFS: return error if link and unlink race
  UBIFS: reset no_space flag after inode deletion
2009-06-17 09:46:33 -07:00
Linus Torvalds
517d08699b Merge branch 'akpm'
* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16 19:50:13 -07:00
Chris Peterson
009789f040 slow-work: use round_jiffies() for thread pool's cull and OOM timers
Round the slow work queue's cull and OOM timeouts to whole second boundary
with round_jiffies().  The slow work queue uses a pair of timers to cull
idle threads and, after OOM, to delay new thread creation.

This patch also extracts the mod_timer() logic for the cull timer into a
separate helper function.

By rounding non-time-critical timers such as these to whole seconds, they
will be batched up to fire at the same time rather than being spread out.
This allows the CPU wake up less, which saves power.

Signed-off-by: Chris Peterson <cpeterso@cpeterso.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:49 -07:00
Alexey Dobriyan
30639b6af8 groups: move code to kernel/groups.c
Move supplementary groups implementation to kernel/groups.c .
kernel/sys.c already accumulated quite a few random stuff.

Do strictly copy/paste + add required headers to compile.  Compile-tested
on many configs and archs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:48 -07:00
Robert P. J. Day
b33112d1cc kernel/kfifo.c: replace conditional test with is_power_of_2()
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:47 -07:00
KOSAKI Motohiro
6837765963 mm: remove CONFIG_UNEVICTABLE_LRU config option
Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:42 -07:00
Rafael J. Wysocki
7f33d49a2e mm, PM/Freezer: Disable OOM killer when tasks are frozen
Currently, the following scenario appears to be possible in theory:

* Tasks are frozen for hibernation or suspend.
* Free pages are almost exhausted.
* Certain piece of code in the suspend code path attempts to allocate
  some memory using GFP_KERNEL and allocation order less than or
  equal to PAGE_ALLOC_COSTLY_ORDER.
* __alloc_pages_internal() cannot find a free page so it invokes the
  OOM killer.
* The OOM killer attempts to kill a task, but the task is frozen, so
  it doesn't die immediately.
* __alloc_pages_internal() jumps to 'restart', unsuccessfully tries
  to find a free page and invokes the OOM killer.
* No progress can be made.

Although it is now hard to trigger during hibernation due to the memory
shrinking carried out by the hibernation code, it is theoretically
possible to trigger during suspend after the memory shrinking has been
removed from that code path.  Moreover, since memory allocations are
going to be used for the hibernation memory shrinking, it will be even
more likely to happen during hibernation.

To prevent it from happening, introduce the oom_killer_disabled switch
that will cause __alloc_pages_internal() to fail in the situations in
which the OOM killer would have been called and make the freezer set
this switch after tasks have been successfully frozen.

[akpm@linux-foundation.org: be nicer to the namespace]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
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>
2009-06-16 19:47:40 -07:00
Mel Gorman
6484eb3e2a page allocator: do not check NUMA node ID when the caller knows the node is valid
Callers of alloc_pages_node() can optionally specify -1 as a node to mean
"allocate from the current node".  However, a number of the callers in
fast paths know for a fact their node is valid.  To avoid a comparison and
branch, this patch adds alloc_pages_exact_node() that only checks the nid
with VM_BUG_ON().  Callers that know their node is valid are then
converted.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>	[for the SLOB NUMA bits]
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00
Miao Xie
58568d2a82 cpuset,mm: update tasks' mems_allowed in time
Fix allocating page cache/slab object on the unallowed node when memory
spread is set by updating tasks' mems_allowed after its cpuset's mems is
changed.

In order to update tasks' mems_allowed in time, we must modify the code of
memory policy.  Because the memory policy is applied in the process's
context originally.  After applying this patch, one task directly
manipulates anothers mems_allowed, and we use alloc_lock in the
task_struct to protect mems_allowed and memory policy of the task.

But in the fast path, we didn't use lock to protect them, because adding a
lock may lead to performance regression.  But if we don't add a lock,the
task might see no nodes when changing cpuset's mems_allowed to some
non-overlapping set.  In order to avoid it, we set all new allowed nodes,
then clear newly disallowed ones.

[lee.schermerhorn@hp.com:
  The rework of mpol_new() to extract the adjusting of the node mask to
  apply cpuset and mpol flags "context" breaks set_mempolicy() and mbind()
  with MPOL_PREFERRED and a NULL nodemask--i.e., explicit local
  allocation.  Fix this by adding the check for MPOL_PREFERRED and empty
  node mask to mpol_new_mpolicy().

  Remove the now unneeded 'nodes = NULL' from mpol_new().

  Note that mpol_new_mempolicy() is always called with a non-NULL
  'nodes' parameter now that it has been removed from mpol_new().
  Therefore, we don't need to test nodes for NULL before testing it for
  'empty'.  However, just to be extra paranoid, add a VM_BUG_ON() to
  verify this assumption.]
[lee.schermerhorn@hp.com:

  I don't think the function name 'mpol_new_mempolicy' is descriptive
  enough to differentiate it from mpol_new().

  This function applies cpuset set context, usually constraining nodes
  to those allowed by the cpuset.  However, when the 'RELATIVE_NODES flag
  is set, it also translates the nodes.  So I settled on
  'mpol_set_nodemask()', because the comment block for mpol_new() mentions
  that we need to call this function to "set nodes".

  Some additional minor line length, whitespace and typo cleanup.]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Miao Xie
950592f7b9 cpusets: update tasks' page/slab spread flags in time
Fix the bug that the kernel didn't spread page cache/slab object evenly
over all the allowed nodes when spread flags were set by updating tasks'
page/slab spread flags in time.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Miao Xie
f3b39d47eb cpusets: restructure the function cpuset_update_task_memory_state()
The kernel still allocates the page caches on old node after modifying its
cpuset's mems when 'memory_spread_page' was set, or it didn't spread the
page cache evenly over all the nodes that faulting task is allowed to usr
after memory_spread_page was set.  it is caused by the old mem_allowed and
flags of the task, the current kernel doesn't updates them unless some
function invokes cpuset_update_task_memory_state(), it is too late
sometimes.We must update the mem_allowed and the flags of the tasks in
time.

Slab has the same problem.

The following patches fix this bug by updating tasks' mem_allowed and
spread flag after its cpuset's mems or spread flag is changed.

This patch:

Extract a function from cpuset_update_task_memory_state().  It will be
used later for update tasks' page/slab spread flags after its cpuset's
flag is set

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Linus Torvalds
b3fec0fe35 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck: (39 commits)
  signal: fix __send_signal() false positive kmemcheck warning
  fs: fix do_mount_root() false positive kmemcheck warning
  fs: introduce __getname_gfp()
  trace: annotate bitfields in struct ring_buffer_event
  net: annotate struct sock bitfield
  c2port: annotate bitfield for kmemcheck
  net: annotate inet_timewait_sock bitfields
  ieee1394/csr1212: fix false positive kmemcheck report
  ieee1394: annotate bitfield
  net: annotate bitfields in struct inet_sock
  net: use kmemcheck bitfields API for skbuff
  kmemcheck: introduce bitfield API
  kmemcheck: add opcode self-testing at boot
  x86: unify pte_hidden
  x86: make _PAGE_HIDDEN conditional
  kmemcheck: make kconfig accessible for other architectures
  kmemcheck: enable in the x86 Kconfig
  kmemcheck: add hooks for the page allocator
  kmemcheck: add hooks for page- and sg-dma-mappings
  kmemcheck: don't track page tables
  ...
2009-06-16 13:09:51 -07:00
Linus Torvalds
6fd03301d7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (64 commits)
  debugfs: use specified mode to possibly mark files read/write only
  debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
  xen: remove driver_data direct access of struct device from more drivers
  usb: gadget: at91_udc: remove driver_data direct access of struct device
  uml: remove driver_data direct access of struct device
  block/ps3: remove driver_data direct access of struct device
  s390: remove driver_data direct access of struct device
  parport: remove driver_data direct access of struct device
  parisc: remove driver_data direct access of struct device
  of_serial: remove driver_data direct access of struct device
  mips: remove driver_data direct access of struct device
  ipmi: remove driver_data direct access of struct device
  infiniband: ehca: remove driver_data direct access of struct device
  ibmvscsi: gadget: at91_udc: remove driver_data direct access of struct device
  hvcs: remove driver_data direct access of struct device
  xen block: remove driver_data direct access of struct device
  thermal: remove driver_data direct access of struct device
  scsi: remove driver_data direct access of struct device
  pcmcia: remove driver_data direct access of struct device
  PCIE: remove driver_data direct access of struct device
  ...

Manually fix up trivial conflicts due to different direct driver_data
direct access fixups in drivers/block/{ps3disk.c,ps3vram.c}
2009-06-16 12:57:37 -07:00
Linus Torvalds
b231125af7 printk: add KERN_DEFAULT loglevel to print_modules()
Several WARN_ON() messages omit the '\n' at the end of the string, which
is a simple (and understandable) error.  The next line printed after
that warning line is usually the current module list, and that printk
does not have a log-level marker - resulting in one long mixed-up line.

Adding this loglevel marker will now avoid this unreadable mess.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 11:07:14 -07:00
Linus Torvalds
e28d713704 printk: Add KERN_DEFAULT printk log-level
This adds a KERN_DEFAULT loglevel marker, for when you cannot decide
which loglevel you want, and just want to keep an existing printk
with the default loglevel.

The difference between having KERN_DEFAULT and having no log-level
marker at all is two-fold:

 - having the log-level marker will now force a new-line if the
   previous printout had not added one (perhaps because it forgot,
   but perhaps because it expected a continuation)

 - having a log-level marker is required if you are printing out a
   message that otherwise itself could perhaps otherwise be mistaken
   for a log-level.

Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 11:02:28 -07:00
Linus Torvalds
5fd29d6ccb printk: clean up handling of log-levels and newlines
It used to be that we would only look at the log-level in a printk()
after explicit newlines, which can cause annoying problems when the
previous printk() did not end with a '\n'. In that case, the log-level
marker would be just printed out in the middle of the line, and be
seen as just noise rather than change the logging level.

This changes things to always look at the log-level in the first
bytes of the printout. If a log level marker is found, it is always
used as the log-level. Additionally, if no newline existed, one is
added (unless the log-level is the explicit KERN_CONT marker, to
explicitly show that it's a continuation of a previous line).

Acked-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 10:57:02 -07:00
GeunSik Lim
156f5a7801 debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
Many developers use "/debug/" or "/debugfs/" or "/sys/kernel/debug/"
directory name to mount debugfs filesystem for ftrace according to
./Documentation/tracers/ftrace.txt file.

And, three directory names(ex:/debug/, /debugfs/, /sys/kernel/debug/) is
existed in kernel source like ftrace, DRM, Wireless, Documentation,
Network[sky2]files to mount debugfs filesystem.

debugfs means debug filesystem for debugging easy to use by greg kroah
hartman. "/sys/kernel/debug/" name is suitable as directory name
of debugfs filesystem.
- debugfs related reference: http://lwn.net/Articles/334546/

Fix inconsistency of directory name to mount debugfs filesystem.

* From Steven Rostedt
  - find_debugfs() and tracing_files() in this patch.

Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com>
Acked-by     : Inaky Perez-Gonzalez <inaky@linux.intel.com>
Reviewed-by  : Steven Rostedt <rostedt@goodmis.org>
Reviewed-by  : James Smart <james.smart@emulex.com>
CC: Jiri Kosina <trivial@kernel.org>
CC: David Airlie <airlied@linux.ie>
CC: Peter Osterlund <petero2@telia.com>
CC: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
CC: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
CC: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:28 -07:00