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Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple per-subnode APIs

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From Tejun Heo <tj@kernel.org>
Newsgroups linux.kernel
Subject Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple per-subnode APIs
Date Tue, 12 Jul 2016 21:00:01 +0200
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Hello,

On Tue, Jul 12, 2016 at 02:51:31PM -0400, Waiman Long wrote:
> The last 2 RFC patches were created in response to Andi's comment to have
> coarser granularity than per-cpu. In this particular use case, I don't think
> global list traversals are frequent enough to really have any noticeable
> performance impact. So I don't have any benchmark number to support this
> change. However, it may not be true for other future use cases.
> 
> These 2 patches were created to gauge if using a per-subnode API for this
> use case is a good idea or not. I am perfectly happy to keep it as per-cpu
> and scrap the last 2 RFC patches. My main goal is to make this patchset more
> acceptable to be moved forward instead of staying in limbo.

I see.  I don't think it makes sense to add a whole new API for a use
case which doesn't really need it without any backing data.  It
probably would be best to revisit this when we're dealing with an
actually problematic case.

Thanks.

-- 
tejun

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Thread

[PATCH v2 0/7] vfs: Use dlock list for SB's s_inodes list Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
  [RFC PATCH v2 7/7] lib/dlock-list: Use the per-subnode APIs for managing lists Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
  [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected lists Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
    Re: [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected  lists Tejun Heo <tj@kernel.org> - 2016-07-13 18:20 +0200
      Re: [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected  lists Tejun Heo <tj@kernel.org> - 2016-07-14 14:00 +0200
        Re: [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected  lists Jan Kara <jack@suse.cz> - 2016-07-14 16:40 +0200
          Re: [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected  lists Tejun Heo <tj@kernel.org> - 2016-07-14 17:00 +0200
        Re: [PATCH v2 1/7] lib/dlock-list: Distributed and lock-protected  lists Tejun Heo <tj@kernel.org> - 2016-07-14 19:50 +0200
  [PATCH v2 2/7] lib/dlock-list: Add __percpu modifier for parameters Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
    Re: [PATCH v2 2/7] lib/dlock-list: Add __percpu modifier for  parameters Tejun Heo <tj@kernel.org> - 2016-07-13 18:20 +0200
  [PATCH v2 5/7] vfs: Use dlock list for superblock's inode list Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
  [PATCH v2 3/7] fsnotify: Simplify inode iteration on umount Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
  [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple per-subnode APIs Waiman Long <Waiman.Long@hpe.com> - 2016-07-11 19:40 +0200
    Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple  per-subnode APIs Boqun Feng <boqun.feng@gmail.com> - 2016-07-12 05:20 +0200
    Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple  per-subnode APIs Tejun Heo <tj@kernel.org> - 2016-07-12 16:30 +0200
      Re: [RFC PATCH v2 6/7] lib/persubnode: Introducing a simple  per-subnode APIs Tejun Heo <tj@kernel.org> - 2016-07-12 21:00 +0200

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