Re: [RFC PATCH] alispinlock: acceleration from lock integration on multi-core platform

From	Waiman Long <waiman.long@hpe.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH] alispinlock: acceleration from lock integration on multi-core platform
Date	2016-02-03 22:50 +0100
Message-ID	<qYdtg-7qy-13@gated-at.bofh.it> (permalink)
References	(7 earlier) <qQ7En-1Fv-21@gated-at.bofh.it> <qQLip-4lJ-3@gated-at.bofh.it> <qSAiS-5me-27@gated-at.bofh.it> <qSGxY-1lu-19@gated-at.bofh.it> <qXXya-5xy-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 02/02/2016 11:40 PM, Ling Ma wrote:
> Longman,
>
> The attachment include user space code(thread.c), and kernel
> patch(ali_work_queue.patch) based on 4.3.0-rc4,
> we replaced all original spinlock (list_lock) in slab.h/c  with the
> new mechanism.
>
> The thread.c in user space caused lots of hot kernel spinlock from
> __kmalloc and kfree,
> perf top -d1 shows ~25%  before ali_work_queue.patch,after appending
> this patch ,
> the synchronous operation consumption from __kmalloc and kfree is
> reduced from 25% to ~15% on Intel E5-2699V3
> (we also observed the output from user space code (thread.c) is
> improved clearly)

I have 2 major comments here. First of all, you should break up your 
patch into smaller ones. Large patch like the one in the tar ball is 
hard to review. Secondly, you are modifying over 1000 lines of code in 
mm/slab.c with some modest increase in performance. That can be hard to 
justify. Maybe you should find other use cases that involve less 
changes, but still have noticeable performance improvement. That will 
make it easier to be accepted.

Cheers,
Longman

Thread

Re: [RFC PATCH] alispinlock: acceleration from lock integration on  multi-core platform Ling Ma <ling.ma.program@gmail.com> - 2016-02-03 05:50 +0100
  Re: [RFC PATCH] alispinlock: acceleration from lock integration on  multi-core platform Ling Ma <ling.ma.program@gmail.com> - 2016-02-03 07:10 +0100
  Re: [RFC PATCH] alispinlock: acceleration from lock integration on  multi-core platform Waiman Long <waiman.long@hpe.com> - 2016-02-03 22:50 +0100
    Re: [RFC PATCH] alispinlock: acceleration from lock integration on  multi-core platform Ling Ma <ling.ma.program@gmail.com> - 2016-02-04 08:10 +0100

csiph-web