Re: [PATCH][RFC]fix soft lock up at NFS mount by per-SB LRU-listof unused dentries

From: Kentaro Makita
Date: Thu May 22 2008 - 04:21:19 EST

Andrew Morton wrote:
> On Thu, 22 May 2008 11:22:18 +0900 Kentaro Makita <k-makita@xxxxxxxxxxxxxxxxxx> wrote:
>> [Summary]
>> Split LRU-list of unused dentries to each superblocks to avoid soft lock up
>> at NFS mounts and remounting any filesystem.
>> Previosly I posted are:
>> [Descriptions]
>> - background
>> dentry_unused is a list of dentries which is not in use. This works
>> as a cache against not-exisiting files. dentry_unused grows up when
>> directories or files are removed. This list can be very long if
>> there is huge free memory.
> The dentry_unused inodes are not actually not-existing files. They are
> dentries which refer to live files (and, iirc, negative dentries) but
> which nobody is actually using - for example, regular files which
> nobody currently has open.
> I changed the changelog text to reflect that.
Oh, Thank you for your good information and fixing.
>> - what's problem
>> This patch is against linux-2.6.26-rc3. Tested on x86_64.
> Looks good to me, thanks. And no, the loss of the strict global LRU
> handling of the dentry LRU is unlikely to be an issue.
>> Based on David Chinner's "Per-superblock unused dentry LRU lists V3".
>> ...
>> Signed-off-by: Kentaro Makita <k-makita@xxxxxxxxxxxxxxxxxx>
> I guess we should ask David for his signed-off-by: on this.
Thank you for your works too, David.

Best Regards,
Kentaro Makita

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