Messages in this thread | | | Date | Tue, 01 Jul 2014 10:07:06 +0900 | From | Gioh Kim <> | Subject | Re: [RFC] CMA page migration failure due to buffers on bh_lru |
| |
Hi,Laura.
I have a question.
Does the __evict_bh_lru() not need bh_lru_lock()? The get_cpu_var() has already preenpt_disable() and can prevent other thread. But get_cpu_var cannot prevent IRQ context such like page-fault. I think if a page-fault occured and a file is read in IRQ context it can change cpu-lru.
Is my concern correct?
2014-06-30 오전 4:49, Laura Abbott 쓴 글: > (cc-ing Hugh since he had comments on the patch before) > > On 6/26/2014 4:23 PM, Gioh Kim wrote: >> >> >> 2014-06-27 오전 12:57, Michal Nazarewicz 쓴 글: >>> On Tue, Jun 24 2014, Gioh Kim <gioh.kim@lge.com> wrote: >>>> Hello, >>>> >>>> I am trying to apply CMA feature for my platform. >>>> My kernel version, 3.10.x, is not allocating memory from CMA area so that I applied >>>> a Joonsoo Kim's patch (https://lkml.org/lkml/2014/5/28/64). >>>> Now my platform can use CMA area effectively. >>>> >>>> But I have many failures to allocate memory from CMA area. >>>> I found the same situation to Laura Abbott's patch descrbing, >>>> https://lkml.org/lkml/2012/8/31/313, >>>> that releases buffer-heads attached at CPU's LRU list. >>>> >>>> If Joonsoo's patch is applied and/or CMA feature is applied more and more, >>>> buffer-heads problem is going to be serious definitely. >>>> >>>> Please look into the Laura's patch again. >>>> I think it must be applied with Joonsoo's patch. >>> >>> Just to make sure I understood you correctly, you're saying Laura's >>> patch at <https://lkml.org/lkml/2012/8/31/313> fixes your issue? >>> >> >> Yes, it is. > > I submitted this before and it was suggested that this was more > related to filesystems > > http://marc.info/?l=linaro-mm-sig&m=137645770708817&w=2 > > I never saw more discussion and pushed this into the 'CMA hacks' pile. > So far we've been keeping the patch out of tree and it's useful to know > that others have found the same problem. I'm willing to resubmit the > patch for further discussion. > > Thanks, > Laura > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |