Re: ipc,sem: sysv semaphore scalability

From: Rik van Riel
Date: Thu Mar 21 2013 - 23:40:22 EST

On 03/21/2013 09:23 PM, Linus Torvalds wrote:
On Thu, Mar 21, 2013 at 6:12 PM, Davidlohr Bueso <davidlohr.bueso@xxxxxx> wrote:

ipc lock contention:
100 users: 8,74% (vanilla) 3.17% (v3 patchset)
400 users: 21,86% (vanilla) 5.23% (v3 patchset)
800 users 84,35% (vanilla) 7.39% (v3 patchset)

Ok, I'd call that pretty much "solved". Sure, it's still visible, but
for being a benchmark that apparently does little else than pound on
those sysv semaphores, I think we can consider it pretty much fine.
I'm going to assume that anybody who actually then does any real work
(ie a database) is never going to see even close to this bad

Good job, Rik. I'm assuming we'll be merging this during the 3.10
merge window, and hopefully the merge conflicts will be sorted out
too. Rik, Peter, can you look at each others patches and see if you
can get that sorted out for Andrew?

Will do.

I will rebase this series on top of what is in linux-next.

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