Re: [PATCH] fs/locks.c: prepare for BKL removal

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, Sep 18, 2010 at 03:09:31PM +0200, Arnd Bergmann wrote:
> This prepares the removal of the big kernel lock from the
> file locking code. We still use the BKL as long as fs/lockd
> uses it and ceph might sleep, but we can flip the definition
> to a private spinlock as soon as that's done.
> All users outside of fs/lockd get converted to use
> lock_flocks() instead of lock_kernel() where appropriate.
> 
> Based on an earlier patch to use a spinlock from Matthew
> Wilcox, who has attempted this a few times before. An even
> earlier attempt to use a semaphore instead of the BKL
> apparently was made by Andrew Morton about ten years ago,
> but reverted for performance reasons.

Actually, I attempted the semaphore conversion ten years ago, but Andrew
Morton reverted it due to the performance regression.  I believe it was
Apache, when it was using file locks to synchronise between threads.

Patch looks good; Acked-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux