[lkml]   [2002]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRE: Cache coherency and snooping
Thanks Ralf and Alan,

What if I allocate memory at boot-time using alloc_bootmem*(..)?


-----Original Message-----
From: Ralf Baechle []
Sent: Tuesday, August 13, 2002 5:08 PM
To: Imran Badr
Subject: Re: Cache coherency and snooping

On Tue, Aug 13, 2002 at 04:22:31PM -0700, Imran Badr wrote:

> How can I define a certain region of memory so that it is never cached? I
> want to use non-cached region of memory to communicate to my PCI device to
> avoid system overhead in cache snooping.

On every sane platform the hardware performs better at keeping the
coherency than software ever could. Don't even think about it unless
you for some reason absolutely must disable caching. Aside and as Alan
already mentioned the allocation of uncached memory isn't supported.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:28    [W:0.114 / U:3.172 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site