Hi Dan, I'm OK to save memory here. I'd like to send v2. Thanks, Xuelin Shi -----Original Message----- From: Dan Williams [mailto:dan.j.williams@xxxxxxxxx] Sent: 2014年3月19日 23:44 To: Shi Xuelin-B29237 Cc: Vinod Koul; linuxppc-dev; dmaengine@xxxxxxxxxxxxxxx Subject: Re: [PATCH] fix dmaengine_unmap failure. On Tue, Mar 18, 2014 at 11:39 PM, Xuelin Shi <xuelin.shi@xxxxxxxxxxxxx> 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. ?韬{.n?????%??檩??w?{.n???Ё?撖)?骅w* jg????????G??⒏ ⒎?:+v???????? ????＂??????
