All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jim Rees <rees@umich.edu>
To: Vivek Trivedi <vtrivedi018@gmail.com>
Cc: "Myklebust, Trond" <Trond.Myklebust@netapp.com>,
	linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	Namjae Jeon <linkinjeon@gmail.com>,
	amit.sahrawat83@gmail.com
Subject: Re: NFS: low read/stat performance on small files
Date: Fri, 23 Mar 2012 07:49:13 -0400	[thread overview]
Message-ID: <20120323114913.GB24489@umich.edu> (raw)
In-Reply-To: <CAKX=r8A90b25VKXC1qtAota9DqDrj37xFT511DuvrZ=1Eux6Xw@mail.gmail.com>

Vivek Trivedi wrote:

  204800 bytes (200.0KB) copied, 0.027074 seconds, 7.2MB/s
  Read speed for 200KB file is 7.2 MB

  104857600 bytes (100.0MB) copied, 9.351221 seconds, 10.7MB/s
  Read speed for 100MB file is 10.7 MB
  
  As you see read speed for 200KB file is only 7.2MB/sec while it is
  10.7 MB/sec when we read 100MB file.
  Why there is so much difference in read performance ?
  Is there any way to achieve high read speed for small files ?

That seems excellent to me.  204800 bytes at 11213252 per sec would be 18.2
msec, so your per-file overhead is around 9 msec.  The disk latency alone
would normally be more than that.

  reply	other threads:[~2012-03-23 12:15 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-23 11:17 NFS: low read/stat performance on small files Vivek Trivedi
2012-03-23 11:49 ` Jim Rees [this message]
2012-03-23 12:16   ` Myklebust, Trond
2012-03-23 12:16     ` Myklebust, Trond
2012-03-24  7:02     ` Namjae Jeon
2012-03-29 15:52     ` Kevin Graham
2012-03-29 16:16       ` Myklebust, Trond

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=20120323114913.GB24489@umich.edu \
    --to=rees@umich.edu \
    --cc=Trond.Myklebust@netapp.com \
    --cc=amit.sahrawat83@gmail.com \
    --cc=linkinjeon@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=vtrivedi018@gmail.com \
    /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.