From: Andreas Dilger <adilger@sun.com>
To: Alex Tomas <alex.tomas@sun.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
tytso@mit.edu, cmm@us.ibm.com, linux-ext4@vger.kernel.org
Subject: Re: [PATCH] ext4: Fix the soft lockup with multi block allocator.
Date: Mon, 24 Dec 2007 11:45:32 -0700 [thread overview]
Message-ID: <20071224184532.GA3421@webber.adilger.int> (raw)
In-Reply-To: <476FF805.4050700@sun.com>
On Dec 24, 2007 21:18 +0300, Alex Tomas wrote:
> Andreas Dilger wrote:
>> On Dec 21, 2007 16:39 +0530, Aneesh Kumar K.V wrote:
>>> @@ -3790,7 +3782,9 @@ repeat:
>>> /* if we still need more blocks and some PAs were used, try again */
>>> if (free < needed && busy) {
>>> + busy = 0;
>>> ext4_unlock_group(sb, group);
>>> + schedule_timeout(HZ);
>>> goto repeat;
>>> }
>>
>> Is there nothing we could actually wait on instead of just sleeping for
>> 1 second?
>
> actually it was done for simplicity - in my tests busy PA happened quite rare.
> I have no objection to improve this with special wait queue.
If it is a very rare case, then I have no objection. I just wanted to
avoid some sort of "Nagle" case where suddenly a workload is taking 1s
instead of 1ms to complete each IO.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
next prev parent reply other threads:[~2007-12-24 18:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-21 11:09 [PATCH] ext4: Fix the soft lockup with multi block allocator Aneesh Kumar K.V
2007-12-21 11:21 ` Alex Tomas
2007-12-21 19:10 ` Andreas Dilger
2007-12-24 18:18 ` Alex Tomas
2007-12-24 18:45 ` Andreas Dilger [this message]
2008-01-09 12:10 ` Jan Kara
2008-01-09 18:24 ` Aneesh Kumar K.V
2008-01-09 18:44 ` Jan Kara
2008-01-09 19:11 ` Aneesh Kumar K.V
2008-01-09 22:01 ` Mingming Cao
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