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From: "wuming" <wuming@ict.ac.cn>
To: <linux-mips@linux-mips.org>
Subject: Re: problem about dma
Date: Mon, 20 Dec 2004 17:51:16 +0800	[thread overview]
Message-ID: <002101c4e679$72938bc0$6f64a8c0@spark> (raw)
In-Reply-To: 41C690CF.2010306@niisi.msk.ru


----- Original Message ----- 
From: "Gleb O. Raiko" <raiko@niisi.msk.ru>
To: "wuming" <wuming@ict.ac.cn>
Cc: <linux-mips@linux-mips.org>
Sent: Monday, December 20, 2004 4:43 PM
Subject: Re: problem about dma


> In 2.4, memcpy's prefetch may (and, in practice, do, no smiles, it cost 
> me a lot of time to realize) access that memory. I though it has been 
> fixed in 2.6 someday.
> 
> Regards,
> Gleb.
> 
Thank you! :)
But I think it is not the only reason, because the CPU on my platform does not 
support the "pref" instruction. So, memcpy's prefetch may have no effect on that 
arrange of memory.


WARNING: multiple messages have this Message-ID (diff)
From: "wuming" <wuming@ict.ac.cn>
To: linux-mips@linux-mips.org
Subject: Re: problem about dma
Date: Mon, 20 Dec 2004 17:51:16 +0800	[thread overview]
Message-ID: <002101c4e679$72938bc0$6f64a8c0@spark> (raw)
Message-ID: <20041220095116.InMaU5ekHeRCJgfY1hN6YkeyC_B45GfpYWCG0Dwa1rA@z> (raw)
In-Reply-To: 41C690CF.2010306@niisi.msk.ru


----- Original Message ----- 
From: "Gleb O. Raiko" <raiko@niisi.msk.ru>
To: "wuming" <wuming@ict.ac.cn>
Cc: <linux-mips@linux-mips.org>
Sent: Monday, December 20, 2004 4:43 PM
Subject: Re: problem about dma


> In 2.4, memcpy's prefetch may (and, in practice, do, no smiles, it cost 
> me a lot of time to realize) access that memory. I though it has been 
> fixed in 2.6 someday.
> 
> Regards,
> Gleb.
> 
Thank you! :)
But I think it is not the only reason, because the CPU on my platform does not 
support the "pref" instruction. So, memcpy's prefetch may have no effect on that 
arrange of memory.


  reply	other threads:[~2004-12-20  9:51 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-20  3:46 problem about dma wuming
2004-12-20  3:46 ` wuming
2004-12-20  8:43 ` Gleb O. Raiko
2004-12-20  9:51   ` wuming [this message]
2004-12-20  9:51     ` wuming
2004-12-20 13:14     ` Fuxin Zhang

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