From: David Miller <davem@davemloft.net>
To: fujita.tomonori@lab.ntt.co.jp
Cc: tsbogend@alpha.franken.de, linux-scsi@vger.kernel.org,
linux-ide@vger.kernel.org, jens.axboe@oracle.com,
bzolnier@gmail.com, James.Bottomley@HansenPartnership.com,
jeff@garzik.org, akpm@linux-foundation.org
Subject: Re: [PATCH 0/4] revert the commit 22a9189f (cdrom: use kmalloced buffers instead of buffers on stack)
Date: Wed, 21 May 2008 18:18:47 -0700 (PDT) [thread overview]
Message-ID: <20080521.181847.157652663.davem@davemloft.net> (raw)
In-Reply-To: <20080522095506E.tomof@acm.org>
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Date: Thu, 22 May 2008 10:13:31 +0900
> DMA on stack is forbidden because of non coherent architecutes and
> architectures can't uses stack addresses for DMA? What architectures
> can't uses stack addresses for DMA? Would it be better to just forbid
> using stack addresses for DMA on all the architectures at all times?
Rather, the real problem is that some architectures map the kernel
stack virtually, and as a result virt_to_page() and things like that
will not work.
It really is fully not working to put DMA buffers on the stack
in these cases.
next prev parent reply other threads:[~2008-05-22 1:18 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-20 4:58 [PATCH 0/4] revert the commit 22a9189f (cdrom: use kmalloced buffers instead of buffers on stack) FUJITA Tomonori
2008-05-20 4:58 ` [PATCH 1/4] block: use ARCH_KMALLOC_MINALIGN as the default dma pad mask FUJITA Tomonori
2008-05-20 4:58 ` [PATCH 2/4] block: add blk_queue_update_dma_pad FUJITA Tomonori
2008-05-20 4:58 ` [PATCH 3/4] ide: use the dma safe check for REQ_TYPE_ATA_PC FUJITA Tomonori
2008-05-20 4:58 ` [PATCH 4/4] cdrom: revert commit 22a9189 (cdrom: use kmalloced buffers instead of buffers on stack) FUJITA Tomonori
2008-05-20 7:33 ` Elias Oltmanns
2008-05-20 7:42 ` Jim Paris
2008-05-20 8:14 ` Elias Oltmanns
2008-05-28 6:43 ` [PATCH 3/4] ide: use the dma safe check for REQ_TYPE_ATA_PC Borislav Petkov
2008-05-20 9:31 ` [PATCH 1/4] block: use ARCH_KMALLOC_MINALIGN as the default dma pad mask Andrew Morton
2008-05-20 9:38 ` Herbert Xu
2008-05-20 9:52 ` Andrew Morton
2008-05-20 9:58 ` FUJITA Tomonori
2008-05-20 11:32 ` Herbert Xu
2008-05-20 13:25 ` FUJITA Tomonori
2008-05-20 15:34 ` Herbert Xu
2008-05-20 15:53 ` Plans for libsas and SAS-2? Marushak, Nathan
2008-05-20 16:09 ` [PATCH 1/4] block: use ARCH_KMALLOC_MINALIGN as the default dma pad mask FUJITA Tomonori
2008-05-21 1:26 ` Herbert Xu
2008-05-21 1:36 ` FUJITA Tomonori
2008-05-21 3:16 ` Herbert Xu
2008-05-21 6:54 ` FUJITA Tomonori
2008-05-21 8:47 ` Herbert Xu
2008-05-21 9:34 ` FUJITA Tomonori
2008-05-21 10:05 ` Herbert Xu
2008-05-21 11:01 ` FUJITA Tomonori
2008-05-21 11:25 ` Herbert Xu
2008-05-21 12:09 ` FUJITA Tomonori
2008-05-21 12:22 ` Herbert Xu
2008-05-21 12:46 ` FUJITA Tomonori
2008-05-21 12:55 ` FUJITA Tomonori
2008-05-21 13:19 ` Herbert Xu
2008-05-21 13:18 ` Herbert Xu
2008-05-22 1:14 ` FUJITA Tomonori
2008-05-22 1:19 ` David Miller
2008-05-22 1:21 ` Herbert Xu
2008-05-22 1:32 ` FUJITA Tomonori
2008-05-22 1:56 ` Herbert Xu
2008-05-20 9:55 ` Paul Mundt
2008-05-21 22:11 ` [PATCH 0/4] revert the commit 22a9189f (cdrom: use kmalloced buffers instead of buffers on stack) Thomas Bogendoerfer
2008-05-22 1:13 ` FUJITA Tomonori
2008-05-22 1:18 ` David Miller [this message]
2008-05-22 8:43 ` James Bottomley
2008-05-26 9:17 ` FUJITA Tomonori
2008-05-27 18:58 ` Bartlomiej Zolnierkiewicz
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