From: Dan Williams <dan.j.williams@intel.com>
To: Xuelin Shi <xuelin.shi@freescale.com>
Cc: Vinod Koul <vinod.koul@intel.com>,
"dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH] fix dmaengine_unmap failure.
Date: Wed, 19 Mar 2014 08:43:52 -0700 [thread overview]
Message-ID: <CAPcyv4imH14PuiZJwMw1B+UnxBgHzPAS22p4b171MrmKDBJM+Q@mail.gmail.com> (raw)
In-Reply-To: <30ef7093dcc247e490831a43355ec10f@BL2PR03MB147.namprd03.prod.outlook.com>
On Tue, Mar 18, 2014 at 11:39 PM, Xuelin Shi <xuelin.shi@freescale.com> wrote:
> Hi Dan,
>
> In async_mult(...) of async_raid6_recov.c, the count 3 is used to request an unmap.
> However the to_cnt and bidi_cnt are both set to 1 and from_cnt to 0.
> Then while trying to do unmap, we are getting the wrong "unmap" from a different mempool.
>
> In this patch, the mempool is associated with the unmap structure instead of computing it again.
> By this way, it is guaranteed that the unmap is the same when we get and put the unmap data.
>
> BTW: the mempool is just used to manage the struct unmap, not the pages.
>
I see, what about just storing the map_cnt at allocation time? It
could be another byte in struct dmaengine_unmap_data rather than an 8
byte pointer.
next prev parent reply other threads:[~2014-03-19 15:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-18 8:32 [PATCH] fix dmaengine_unmap failure xuelin.shi
2014-03-18 17:13 ` Dan Williams
2014-03-19 6:39 ` Xuelin Shi
2014-03-19 15:43 ` Dan Williams [this message]
2014-03-20 6:34 ` Xuelin Shi
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