Re: [PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion batching facility

From	Dave Chinner <david@fromorbit.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion batching facility
Date	2016-02-07 01:00 +0100
Message-ID	<qZkVI-6eE-11@gated-at.bofh.it> (permalink)
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On Wed, Feb 03, 2016 at 06:11:56PM -0500, Waiman Long wrote:
> On 01/31/2016 07:47 PM, Dave Chinner wrote:
> >So at what point does simply replacing the list_head with a list_lru
> >become more efficient than this batch processing (i.e.
> >https://lkml.org/lkml/2015/3/10/660)?  The list_lru isn't a great
> >fit for the inode list (doesn't need any of the special LRU/memcg
> >stuff https://lkml.org/lkml/2015/3/16/261) but it will tell us if,
> >like Ingo suggested, moving more towards a generic per-cpu list
> >would provide better overall performance...
> 
> I will take a look at the list_lru patch to see if that help. As for
> the per-cpu list, I tried that and it didn't quite work out.

OK, see my last email as to why Andi's patch didn't change anything.
The list_lru implementation has a list per node, a lock per node,
and each item is placed on the list for the node it is physically
allocated from. Hence for local workloads, the list/lock that is
accessed for add/remove should be local to the node and hence should
reduce cache line contention mostly to within a single node.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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[PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion batching facility Waiman Long <Waiman.Long@hpe.com> - 2016-01-29 20:40 +0100
  Re: [PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion  batching facility Dave Chinner <david@fromorbit.com> - 2016-02-01 01:50 +0100
    Re: [PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion  batching facility Waiman Long <waiman.long@hpe.com> - 2016-02-04 00:20 +0100
      Re: [PATCH v2 1/3] lib/list_batch: A simple list insertion/deletion  batching facility Dave Chinner <david@fromorbit.com> - 2016-02-07 01:00 +0100

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