From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-scsi@vger.kernel.org, axboe@kernel.dk
Subject: Re: [PATCH] [9/20] Add blk_kmalloc/blk_alloc_pages
Date: Thu, 13 Mar 2008 17:06:20 -0500 [thread overview]
Message-ID: <1205445980.2893.85.camel@localhost.localdomain> (raw)
In-Reply-To: <20080307175408.E290E1B41AE@basil.firstfloor.org>
\On Fri, 2008-03-07 at 18:54 +0100, Andi Kleen wrote:
> When a user is doing IO in the kernel and wants to avoid bouncing
> it is best to just ask the block layer to allocate the memory for it.
> This patch adds two simple wrappers: blk_kmalloc and blk_alloc_pages
> and respective free functions to do this.
>
> blk_alloc_pages is a little unusual in that it takes size
> instead of order arguments -- i did this because I have later
> patches to convert it over to a new allocator which does not
> require power of two for pages.
I really don't like this ... it's wedging something in the block layer
that shouldn't be there just to avoid doing it properly in terms of
allocations on the device dma_mask.
I also think the kfree takes a length part is asking for trouble because
it's pretty fragile.
However, if Jens will ack it, I'll (reluctantly) add it.
James
next prev parent reply other threads:[~2008-03-13 22:06 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-07 17:53 [PATCH] [0/20] Remove isa_unchecked_dma and some more GFP_DMAs in the mid layer v3 Andi Kleen
2008-03-07 17:54 ` [PATCH] [1/20] Add sense_buffer_isa to host template Andi Kleen
2008-03-07 17:54 ` [PATCH] [2/20] Remove unchecked_isa in BusLogic Andi Kleen
2008-03-07 17:54 ` [PATCH] [3/20] Remove unchecked_isa_dma in advansys.c Andi Kleen
2008-03-07 17:54 ` [PATCH] [4/20] Remove unchecked_isa_dma in gdth Andi Kleen
2008-03-07 17:54 ` [PATCH] [5/20] Remove unchecked_isa_dma in eata.c Andi Kleen
2008-03-07 17:54 ` [PATCH] [6/20] Remove unchecked_isa_dma in aha1542 Andi Kleen
2008-03-07 17:54 ` [PATCH] [7/20] Remove unchecked_isa_dma in aha152x/wd7000/sym53c416/u14-34f/NCR53c406a Andi Kleen
2008-03-07 17:54 ` [PATCH] [8/20] Remove random noop unchecked_isa_dma users Andi Kleen
2008-03-07 17:54 ` [PATCH] [9/20] Add blk_kmalloc/blk_alloc_pages Andi Kleen
2008-03-13 22:06 ` James Bottomley [this message]
2008-03-14 13:48 ` Jens Axboe
2008-03-14 13:59 ` Andi Kleen
2008-03-17 8:27 ` Jens Axboe
2008-03-17 8:36 ` Andi Kleen
2008-03-17 8:38 ` Jens Axboe
2008-03-17 8:53 ` Andi Kleen
2008-03-17 9:18 ` Boaz Harrosh
2008-03-17 10:03 ` Andi Kleen
2008-03-17 20:29 ` Jens Axboe
2008-03-17 20:45 ` Andi Kleen
2008-03-17 20:46 ` Jens Axboe
2008-03-17 21:34 ` Andi Kleen
2008-03-18 7:26 ` Jens Axboe
2008-04-02 3:37 ` FUJITA Tomonori
2008-04-02 8:43 ` Boaz Harrosh
2008-04-02 11:08 ` FUJITA Tomonori
2008-04-02 11:32 ` Boaz Harrosh
2008-03-17 13:59 ` James Bottomley
2008-03-07 17:54 ` [PATCH] [11/20] Remove unchecked_isa_dma support for hostdata Andi Kleen
2008-03-07 17:54 ` [PATCH] [12/20] Remove unchecked_isa_dma checks in sg.c Andi Kleen
2008-03-07 17:54 ` [PATCH] [13/20] Use blk_kmalloc in scsi_scan Andi Kleen
2008-03-07 17:54 ` [PATCH] [14/20] Don't disable direct_io for unchecked_isa_dma in st.c Andi Kleen
2008-03-14 13:51 ` Jens Axboe
2008-03-14 14:24 ` Christoph Hellwig
2008-03-16 12:39 ` Boaz Harrosh
2008-03-16 12:44 ` Andi Kleen
2008-03-17 8:28 ` Jens Axboe
2008-03-27 17:26 ` Mike Christie
2008-03-17 8:27 ` Jens Axboe
2008-03-17 10:55 ` FUJITA Tomonori
2008-03-17 12:21 ` Boaz Harrosh
2008-03-07 17:54 ` [PATCH] [15/20] Remove automatic block layer bouncing for unchecked_isa_dma Andi Kleen
2008-03-07 17:54 ` [PATCH] [16/20] Convert sr driver over the blk_kmalloc Andi Kleen
2008-03-07 17:54 ` [PATCH] [17/20] Remove unchecked_isa_dma from sysfs Andi Kleen
2008-03-07 17:54 ` [PATCH] [18/20] Switch to a single SCSI command pool Andi Kleen
2008-03-07 17:54 ` [PATCH] [19/20] Finally kill unchecked_isa_dma Andi Kleen
2008-03-07 17:54 ` [PATCH] [20/20] Convert DMA buffers in ch.c to allocate via the block layer Andi Kleen
2008-03-11 17:55 ` [PATCH] [0/20] Remove isa_unchecked_dma and some more GFP_DMAs in the mid layer v3 Boaz Harrosh
2008-03-12 0:56 ` Andi Kleen
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