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From: David Mosberger <davidm@napali.hpl.hp.com>
To: tony.luck@intel.com, akpm@osdl.org
Cc: Andreas Hirstius <Andreas.Hirstius@cern.ch>,
	Bartlomiej ZOLNIERKIEWICZ <Bartlomiej.Zolnierkiewicz@cern.ch>,
	Gelato technical <gelato-technical@gelato.unsw.edu.au>,
	linux-kernel@vger.kernel.org
Subject: Re: [Gelato-technical] Re: Serious performance degradation on a RAID with kernel 2.6.10-bk7 and later
Date: Thu, 21 Apr 2005 08:05:22 -0700	[thread overview]
Message-ID: <16999.49458.498919.807191@napali.hpl.hp.com> (raw)
In-Reply-To: <42678EEA.6070109@cern.ch>

Tony and Andrew,

I just checked 2.6.12-rc3 and the fls() fix is indeed missing.  Do you
know what happened?

	--david

>>>>> On Thu, 21 Apr 2005 13:30:50 +0200, Andreas Hirstius <Andreas.Hirstius@cern.ch> said:

  Andreas> Hi, The fls() patch from David solves the problem :-))

  Andreas> Do you have an idea, when it will be in the mainline
  Andreas> kernel??

  Andreas> Andreas



  Andreas> Bartlomiej ZOLNIERKIEWICZ wrote:

  >>  Hi!
  >> 
  >>> A small update.
  >>> 
  >>> Patching mm/filemap.c is not necessary in order to get the
  >>> improved performance!  It's sufficient to remove
  >>> roundup_pow_of_two from |get_init_ra_size ...
  >>> 
  >>> So a simple one-liner changes to picture dramatically.  But why
  >>> ?!?!?
  >> 
  >> 
  >> roundup_pow_of_two() uses fls() and ia64 has buggy fls()
  >> implementation [ seems that David fixed it but patch is not in
  >> the mainline yet]:
  >> 
  >> http://www.mail-archive.com/linux-ia64@vger.kernel.org/msg01196.html
  >> 
  >> That would also explain why you couldn't reproduce the problem on
  >> ia32 Xeon machines.
  >> 
  >> Bartlomiej
  >> 

  Andreas> _______________________________________________
  Andreas> Gelato-technical mailing list
  Andreas> Gelato-technical@gelato.unsw.edu.au
  Andreas> https://www.gelato.unsw.edu.au/mailman/listinfo/gelato-technical

  reply	other threads:[~2005-04-21 15:06 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-04-20 17:37 Andreas Hirstius
2005-04-20 16:55 ` jmerkey
2005-04-20 18:04   ` Andreas Hirstius
2005-04-20 18:24   ` Andreas Hirstius
2005-04-20 19:17     ` jmerkey
2005-04-21  1:11   ` Nick Piggin
2005-04-21  8:32   ` Andreas Hirstius
     [not found]     ` <58cb370e05042102272ce70f2@mail.gmail.com>
2005-04-21  9:42       ` Bartlomiej ZOLNIERKIEWICZ
2005-04-21 11:30         ` Andreas Hirstius
2005-04-21 15:05           ` David Mosberger [this message]
2005-04-21 17:19 [Gelato-technical] " Luck, Tony
2005-04-21 17:33 ` David Mosberger
2005-04-21 17:39   ` Randy.Dunlap
2005-04-21 17:41 Luck, Tony
2005-04-21 17:48 ` David Mosberger
2005-04-21 18:24 ` Stan Bubrouski
2005-04-21 18:29 Luck, Tony
2005-04-21 18:40 ` Stan Bubrouski

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