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| author | Arnd Bergmann <arnd@arndb.de> | 2011-01-24 10:14:12 +0100 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2011-03-02 22:27:48 +0100 |
| commit | 788257d6101d986ac8f2741aaa35974af47f574c (patch) | |
| tree | 332d877e09d8b5de6a4bdfba8111dd04e84a722b /fs/ufs/Kconfig | |
| parent | 9a311b96c3065f362e3348cb5d7af1a57ca6bff9 (diff) | |
| download | linux-788257d6101d986ac8f2741aaa35974af47f574c.tar.bz2 | |
ufs: remove the BKL
This introduces a new per-superblock mutex in UFS to replace
the big kernel lock. I have been careful to avoid nested
calls to lock_ufs and to get the lock order right with
respect to other mutexes, in particular lock_super.
I did not make any attempt to prove that the big kernel
lock is not needed in a particular place in the code,
which is very possible.
The mutex has a significant performance impact, so it is only
used on SMP or PREEMPT configurations.
As Nick Piggin noticed, any allocation inside of the lock
may end up deadlocking when we get to ufs_getfrag_block
in the reclaim task, so we now use GFP_NOFS.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Nick Bowler <nbowler@elliptictech.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Nick Piggin <npiggin@gmail.com>
Diffstat (limited to 'fs/ufs/Kconfig')
| -rw-r--r-- | fs/ufs/Kconfig | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/ufs/Kconfig b/fs/ufs/Kconfig index 30c8f223253d..e4f10a40768a 100644 --- a/fs/ufs/Kconfig +++ b/fs/ufs/Kconfig @@ -1,7 +1,6 @@ config UFS_FS tristate "UFS file system support (read only)" depends on BLOCK - depends on BKL # probably fixable help BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD, OpenBSD and NeXTstep) use a file system called UFS. Some System V |