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From: Paul Brook <paul@codesourcery.com>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: qemu-devel@nongnu.org, Avi Kivity <avi@redhat.com>
Subject: Re: [Qemu-devel] [PATCH QEMU] transparent hugepage support
Date: Fri, 12 Mar 2010 16:04:03 +0000	[thread overview]
Message-ID: <201003121604.04913.paul@codesourcery.com> (raw)
In-Reply-To: <20100312145228.GR5677@random.random>

> > > $ cat /sys/kernel/mm/transparent_hugepage/hpage_pmd_size
> > > 2097152
> >
> > Is "pmd" x86 specific?
> 
> It's linux specific, this is common code, nothing x86 specific. In
> fact on x86 it's not called pmd but Page Directory. I've actually no
> idea what pmd stands for but it's definitely not x86 specific and it's
> just about the linux common code common to all archs. The reason this
> is called hpage_pmd_size is because it's a #define HPAGE_PMD_SIZE in
> the kernel code. So this entirely match the kernel internals
> _common_code_.

Hmm, ok. I'm guessing linux doesn't support anything other than "huge" and 
"normal" page sizes now, so it's a question of whether we want it to expose 
current implementation details, or say "Align big in-memory things this much 
for optimal TLB behavior".

Paul

  reply	other threads:[~2010-03-12 16:04 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-11 15:14 [Qemu-devel] [PATCH QEMU] transparent hugepage support Andrea Arcangeli
2010-03-11 15:52 ` Avi Kivity
2010-03-11 16:05   ` Andrea Arcangeli
2010-03-13  8:28     ` Avi Kivity
2010-03-13 17:47       ` Andrea Arcangeli
2010-03-11 16:28   ` Paul Brook
2010-03-11 16:46     ` Andrea Arcangeli
2010-03-11 17:55       ` Paul Brook
2010-03-11 18:49         ` Andrea Arcangeli
2010-03-12 11:36           ` Paul Brook
2010-03-12 14:52             ` Andrea Arcangeli
2010-03-12 16:04               ` Paul Brook [this message]
2010-03-12 16:17                 ` Andrea Arcangeli
2010-03-12 16:24                   ` Paul Brook
2010-03-12 16:57                     ` Andrea Arcangeli
2010-03-12 17:10                       ` Paul Brook
2010-03-12 17:41                         ` Andrea Arcangeli
2010-03-12 18:17                           ` Paul Brook
2010-03-12 18:36                             ` Andrea Arcangeli
2010-03-12 18:41                               ` Paul Brook
2010-03-12 18:51                                 ` Andrea Arcangeli
2010-03-12 22:40                                   ` Jamie Lokier
2010-03-12 16:10               ` Paul Brook

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