Commit graph

11 commits

Author SHA1 Message Date
Kent Overstreet
84759c6d18 Revert "rw_semaphore: remove up/down_read_non_owner"
This reverts commit 11b80f459a.

Bcache needs rw semaphores for cache coherency in writeback mode -
writes have to take a read lock on a per cache device rw sem, and
release it when the bio completes.

But since this is for bios it's naturally not in the context of the
process that originally took the lock.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Christoph Hellwig <hch@infradead.org>
CC: David Howells <dhowells@redhat.com>
2013-03-23 15:53:52 -07:00
Jiri Kosina
1b963c81b1 lockdep, rwsem: provide down_write_nest_lock()
down_write_nest_lock() provides a means to annotate locking scenario
where an outer lock is guaranteed to serialize the order nested locks
are being acquired.

This is analogoue to already existing mutex_lock_nest_lock() and
spin_lock_nest_lock().

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mel Gorman <mel@csn.ul.ie>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11 14:54:55 -08:00
David Howells
9ffc93f203 Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Paul Gortmaker
9984de1a5a kernel: Map most files to use export.h instead of module.h
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include <linux/module.h>
  +#include <linux/export.h>

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 09:20:12 -04:00
Arun Sharma
60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Christoph Hellwig
11b80f459a rw_semaphore: remove up/down_read_non_owner
Now that the last users is gone these can be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:47 -04:00
Livio Soares
c7af77b584 sched: mark rwsem functions as __sched for wchan/profiling
This following commit

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fdf8cb0909b531f9ae8f9b9d7e4eb35ba3505f07

un-inlined a low-level rwsem function, but did not mark it as __sched.
The result is that it now shows up as thread wchan (which also affects
/proc/profile stats).  The following simple patch fixes this by properly
marking rwsem_down_failed_common() as a __sched function.

Also in this patch, which is up for discussion, marks down_read() and
down_write() proper as __sched.  For profiling, it is pretty much
useless to know that a semaphore is beig help - it is necessary to know
_which_ one.  By going up another frame on the stack, the information
becomes much more useful.

In summary, the below change to lib/rwsem.c should be applied; the
changes to kernel/rwsem.c could be applied if other kernel hackers agree
with my proposal that down_read()/down_write() in the profile is not
enough.

[ akpm@linux-foundation.org: build fix ]

Signed-off-by: Livio Soares <livio@eecg.toronto.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-18 15:21:13 +01:00
Peter Zijlstra
4fe87745a6 lockstat: hook into spinlock_t, rwlock_t, rwsem and mutex
Call the new lockstat tracking functions from the various lock primitives.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:49 -07:00
Pavel Emelianov
428e6ce023 Lockdep treats down_write_trylock like regular down_write
This causes constructions like

down_write(&mm1->mmap_sem);
if (down_write_trylock(&mm2->mmap_sem)) {
       ...
       up_write(&mm2->mmap_sem);
}
up_write(&mm1->mmap_sem);

generate a lockdep warning about circular locking dependence.

Call rwsem_acquire() with trylock set to 1.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:09 -07:00
Ingo Molnar
4ea2176dfa [PATCH] lockdep: prove rwsem locking correctness
Use the lock validator framework to prove rwsem locking correctness.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:04 -07:00
Ingo Molnar
c4e05116a2 [PATCH] lockdep: clean up rwsems
Clean up rwsems.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:01 -07:00