From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)
To: Sukadev Bhattiprolu
<sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Cc: containers
<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
Balbir <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Dave Hansen
<dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Subject: Re: [PATCH] pid: improved namespaced iteration over processes list
Date: Mon, 15 Dec 2008 13:50:55 -0800 [thread overview]
Message-ID: <m14p159kg0.fsf@frodo.ebiederm.org> (raw)
In-Reply-To: <20081215194603.GA11958-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> (Sukadev Bhattiprolu's message of "Mon, 15 Dec 2008 11:46:03 -0800")
Sukadev Bhattiprolu <sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> writes:
> The obvious trade-off is with systems that don't use containers which
> are porbably the majority at present. For them next_task() now becomes
> more expensive (instead of a simply going to next item on list, they have
> lookup in the pidmap, a lookup in pid hash table followed by mapping the
> pid back to task). I think there was a discussion once on this and the
> conclusion was things like "kill sig -1" are inherently expensive.
Cost wise it would be worth measuring. I have a report that when that
change was made to /proc readdir in /proc sped up.
The problem that I see is that changing generic methods is not generally
applicable.
> Do you need these to be optimized for containers for some other reason ?
A good question.
Eric
next prev parent reply other threads:[~2008-12-15 21:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-15 16:49 [PATCH] pid: improved namespaced iteration over processes list Gowrishankar M
[not found] ` <1229359793-4029-1-git-send-email-gomuthuk-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2008-12-15 18:32 ` Dave Hansen
2008-12-15 19:46 ` Sukadev Bhattiprolu
[not found] ` <20081215194603.GA11958-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-12-15 21:50 ` Eric W. Biederman [this message]
2008-12-15 21:47 ` Eric W. Biederman
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=m14p159kg0.fsf@frodo.ebiederm.org \
--to=ebiederm-as9lmozglivwk0htik3j/w@public.gmane.org \
--cc=balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org \
--cc=containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org \
--cc=dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org \
--cc=sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.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