Re: ipc,sem: sysv semaphore scalability

From: Linus Torvalds
Date: Thu Mar 21 2013 - 21:23:41 EST


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
contention.

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?

Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/