LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Andrew Morton <akpm@osdl.org>
To: Jeff Layton <jlayton@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] i_ino uniqueness: alternate approach -- hash the inodes
Date: Tue, 23 Jan 2007 20:46:48 -0800	[thread overview]
Message-ID: <20070123204648.204b1834.akpm@osdl.org> (raw)
In-Reply-To: <200701161857.l0GIvcaA016196@dantu.rdu.redhat.com>

On Tue, 16 Jan 2007 13:57:38 -0500
Jeff Layton <jlayton@redhat.com> wrote:

> The questions are:
> 
> 1) how much would this slow down lookups for these filesystems?
> 2) is it enough to justify adding more infrastructure to avoid it?
> 
> What might be best is to start with this approach and then only move to using
> IDR or some other scheme if these extra inodes in the hashtable prove to be
> problematic.
> 
> I've done some cursory testing with this patch and the overhead of hashing
> and unhashing the inodes with pipefs is pretty low -- just a few seconds of
> system time added on to the creation and destruction of 10 million pipes (very
> similar to the overhead that the IDR approach would add).

What is the additional overhead, expressed in relative terms?  ie: as a percentage?

  reply	other threads:[~2007-01-24  4:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-16 18:57 Jeff Layton
2007-01-24  4:46 ` Andrew Morton [this message]
2007-01-24 14:22   ` Jeff Layton
2007-01-24 15:21     ` Eric Dumazet
2007-01-24 16:57       ` Jeff Layton
  -- strict thread matches above, loose matches on Subject: below --
2007-01-08 20:46 Jeff Layton
2007-01-10 20:58 ` Eric Sandeen
2006-12-29 19:10 Jeff Layton

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=20070123204648.204b1834.akpm@osdl.org \
    --to=akpm@osdl.org \
    --cc=jlayton@redhat.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [PATCH 0/3] i_ino uniqueness: alternate approach -- hash the inodes' \
    /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

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).