Re: new metadata reader/writer locks in integration-test

[Tsutomu Itoh <t-itoh@jp.fujitsu.com>]

(2011/07/20 16:58), Chris Mason wrote:
> Excerpts from Tsutomu Itoh's message of 2011-07-19 22:08:38 -0400:
>> (2011/07/20 2:30), Chris Mason wrote:
>>> Hi everyone,
>>>
>>> I've pushed out a new integration-test branch, and it includes a new
>>> reader/writer locking scheme for the btree locks.
>>>
>>> We've seen a number of benchmarks dominated by contention on the root
>>> node lock.  This changes our locks into a simple reader/writer lock.
>>> They are based on mutexes so that we still take advantage of the mutex
>>> adaptive spins for write locks (rwsemaphores were much slower).
>>>
>>> I'm also sending the individual commits, please do take a look.
>>
>> I pulled the new integration-test branch, and I got the following
>> warning messages.
>>
>> Jul 20 10:03:30 luna kernel: ------------[ cut here ]------------
>> Jul 20 10:03:30 luna kernel: WARNING: at fs/btrfs/extent-tree.c:5704 btrfs_alloc_free_block+0x178/0x340 [btrfs]()
> 
> Thanks, I think this one is related to Josef's enospc changes, but I'll
> double check.  

>What was the test?

I ran my original test script. 
This script concurrently executes the making deletion of a lot of files,
and the making deletion of a big file, etc. 

Thanks,
Tsutomu