From owner-freebsd-arch  Wed Feb 27 11:55:14 2002
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Date: Wed, 27 Feb 2002 11:55:10 -0800 (PST)
From: Matthew Dillon <dillon@apollo.backplane.com>
Message-Id: <200202271955.g1RJtAj30178@apollo.backplane.com>
To: Alfred Perlstein <bright@mu.org>
Cc: Julian Elischer <julian@elischer.org>,
	Jeff Roberson <jroberson@chesapeake.net>, arch@FreeBSD.ORG
Subject: Re: Slab allocator
References: <200202271926.g1RJQCm29905@apollo.backplane.com> <Pine.BSF.4.21.0202271128580.97278-100000@InterJet.elischer.org> <20020227194256.GR80761@elvis.mu.org>
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:
:* Julian Elischer <julian@elischer.org> [020227 11:40] wrote:
:> 
:> 
:> On Wed, 27 Feb 2002, Matthew Dillon wrote:
:> 
:> > 
:> > :PS Sorry for the long winded email. :-)
:> > 
:> >     Well, one thing I've noticed right off the bat is that the code
:> >     is trying to take advantage of per-cpu queues but is still
:> >     having to obtain a per-cpu mutex to lock the per-cpu queue.
:> 
:> I was wondering abuot that myself :-)
:
:It's basically the pre-emption stuff you guys are wondering about
:along with the possiblity of free'ing back to another cpu's
:cache that may be an issue.
:
:Jeff, are you fee'ing memory back to the cache it was initially
:allocated from or not?
:
:-Alfred

    I don't know what Jeff is doing there but I do seem to recall a
    paper from somewhere that indicated it was more efficient to free memory
    to the current cpu's per-cpu cache rather then back to the original
    cpu's cache because the current cpu's hardware L1/L2 cache likely already
    has mastership of the memory.  I think Linux does things this way.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>

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