From: "John Hawkes" <hawkes@sgi.com>
To: linux-ia64@vger.kernel.org
Subject: Re: should ia64_spinlock_contention do backoff?
Date: Sun, 28 Mar 2004 02:37:39 +0000 [thread overview]
Message-ID: <00c101c4146d$bf3f1630$6400a8c0@PCJohn> (raw)
In-Reply-To: <200403251941.i2PJfrTH026392@napali.hpl.hp.com>
> >>>>> Chris Wedgwood wrote on Fri, March 26, 2004 3:41 PM
> > Does anyone have any idea what locks are most heavily contented for
> > ia64 right now?
>
> This question is a bit too broad, lock contention highly depends on
workload.
I totally agree.
On one AIM7-like workload that I'm using, at 64p the dominant contention is
doing pte_chain_lock() in page_remove_rmap() (11% of the cycles) and
page_add_rmap() (5%). That's not spinlock contention -- it's cacheline
contention. That same workload at 96p shows about 47% of the kernel cycles in
find_get_page() doing the spin_lock(mapping->page_lock), and the
pte_chain_lock() bottleneck has faded into insignificance.
John Hawkes
next prev parent reply other threads:[~2004-03-28 2:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-25 19:41 should ia64_spinlock_contention do backoff? David Mosberger
2004-03-25 20:06 ` John Hawkes
2004-03-25 22:13 ` Keith Owens
2004-03-25 22:28 ` David Mosberger
2004-03-26 17:16 ` markw
2004-03-26 23:41 ` Chris Wedgwood
2004-03-26 23:44 ` David Mosberger
2004-03-27 0:14 ` Chen, Kenneth W
2004-03-28 2:37 ` John Hawkes [this message]
2004-03-28 19:23 ` Matthew Wilcox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='00c101c4146d$bf3f1630$6400a8c0@PCJohn' \
--to=hawkes@sgi.com \
--cc=linux-ia64@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.