From: Yuri Tikhonov <yur@emcraft.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-raid@vger.kernel.org, linuxppc-dev@ozlabs.org, dzu@denx.de,
wd@denx.de, yanok@emcraft.com
Subject: Re[2]: [PATCH 01/11] async_tx: don't use src_list argument of async_xor() for dma addresses
Date: Tue, 9 Dec 2008 03:41:36 +0300 [thread overview]
Message-ID: <1195158776.20081209034136@emcraft.com> (raw)
In-Reply-To: <e9c3a7c20812081631i1e0efff2j953b2e81f6dc6e0e@mail.gmail.com>
On Tuesday, December 9, 2008 you wrote:
> On Mon, Dec 8, 2008 at 2:55 PM, Yuri Tikhonov <yur@emcraft.com> wrote:
>> Using src_list argument of async_xor() as a storage for dma addresses
>> implies sizeof(dma_addr_t) <= sizeof(struct page *) restriction which is
>> not always true (e.g. ppc440spe).
>>
> ppc440spe runs with CONFIG_PHYS_64BIT?
Yep. It uses 36-bit addressing, so this CONFIG is turned on.
> If we do this then we need to also change md to limit the number of
> allowed disks based on the kernel stack size. Because with 256 disks
> a 4K stack can be consumed by one call to async_pq ((256 sources in
> raid5.c + 256 sources async_pq.c) * 8 bytes per source on 64-bit).
On ppc440spe we have 8KB stack, so the things are not worse than on
32-bit archs with 4KB stack. Thus, I guess no changes to md are
required because of this patch. Right?
Regards, Yuri
--
Yuri Tikhonov, Senior Software Engineer
Emcraft Systems, www.emcraft.com
next prev parent reply other threads:[~2008-12-09 0:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-08 21:55 [PATCH 01/11] async_tx: don't use src_list argument of async_xor() for dma addresses Yuri Tikhonov
2008-12-09 0:31 ` Dan Williams
2008-12-09 0:41 ` Yuri Tikhonov [this message]
2008-12-10 1:08 ` Re[2]: " Dan Williams
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