From: Michel Lanners <mlan@cpu.lu>
To: apc@agelectronics.co.uk
Cc: linuxppc-dev@lists.linuxppc.org
Subject: Re: Zero Pages / Cache Coherency
Date: Sun, 29 Aug 1999 22:28:38 +0200 (CEST) [thread overview]
Message-ID: <199908292028.WAA00305@piglet.cpu.lu> (raw)
In-Reply-To: <37C65FF0.A5FBD535@agelectronics.co.uk>
On 27 Aug, this message from Adrian Cox echoed through cyberspace:
>
> I'm currently trying out the pre-zeroing of pages in the idle task, and
> I'm a little worried about its effect on cache-coherency. I can't prove
> to
> my satisfaction that none of the pages being cleared by zero_paged() is
> in the cache, and I'm not sure that turning off caching in the PTE will
> have any effect on cache lines already allocated in L1 or L2.
Cort Dougan had a paper about memory management in Linux on the PowerPC
online at NMT, but at this time the link is broken
(http://www.cs.nmt.edu/~cort/papers/linuxppc-mm/). If I remeber right,
he also spoke about zeroing pegaes in the idle task.
Cort, are you among us? What's up with your personal pages?
> Obviously, any incoherency would be extremely rare, but ensuring that
> the page is invalidated from the caches before it is zeroed has the
> added bonus of removing the need for a flush_page_to_ram() in my
> modified anonymous memory allocator.
I can't remeber whether Cort also treated this subject.
Michel
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next prev parent reply other threads:[~1999-08-29 20:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-08-27 9:52 Zero Pages / Cache Coherency Adrian Cox
1999-08-29 20:28 ` Michel Lanners [this message]
1999-08-30 20:08 ` Geert Uytterhoeven
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