From: Simon Kirby <sim@hostway.ca>
To: linux-nfs@vger.kernel.org
Subject: rpcauth_lookup_credcache hash size
Date: Tue, 9 Nov 2010 10:32:42 -0800 [thread overview]
Message-ID: <20101109183242.GA29915@hostway.ca> (raw)
Hello!
Just decided to run "perf top" on a web server which seemed to be
CPU-bound and saw this at the top:
samples pcnt function DSO
_______ _____ ________________________ __________________
5261.00 11.9% rpcauth_lookup_credcache [kernel.kallsyms]
2429.00 5.5% lex_scan php4
2184.00 5.0% thread_group_cputime [kernel.kallsyms]
1505.00 3.4% established_get_next [kernel.kallsyms]
1083.00 2.5% zendparse php4
1055.00 2.4% zend_hash_find php4
958.00 2.2% lex_scan php5
905.00 2.1% execute php4
890.00 2.0% memcpy /lib/libc-2.7.so
I see this just became configurable, but probably 4 bits (16 buckets?) is
probably a bit small for the default, no? (hlist_head is just a pointer,
4 or 8 bytes per bucket, so the default is 128 bytes on x64 :))
I guess it really needs to auto-scale...
Simon-
reply other threads:[~2010-11-09 18:32 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20101109183242.GA29915@hostway.ca \
--to=sim@hostway.ca \
--cc=linux-nfs@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).