On 09/26/2014 02:28 PM, Rob Clark wrote: > On Fri, Sep 26, 2014 at 6:45 AM, Thomas Hellstrom <[email protected]> > wrote: >> On 09/26/2014 12:40 PM, Chuck Ebbert wrote: >>> On Fri, 26 Sep 2014 09:15:57 +0200 >>> Thomas Hellstrom <[email protected]> wrote: >>> >>>> On 09/26/2014 01:52 AM, Peter Hurley wrote: >>>>> On 09/25/2014 03:35 PM, Chuck Ebbert wrote: >>>>>> There are six ttm patches queued for 3.16.4: >>>>>> >>>>>> drm-ttm-choose-a-pool-to-shrink-correctly-in-ttm_dma_pool_shrink_scan.patch >>>>>> drm-ttm-fix-handling-of-ttm_pl_flag_topdown-v2.patch >>>>>> drm-ttm-fix-possible-division-by-0-in-ttm_dma_pool_shrink_scan.patch >>>>>> drm-ttm-fix-possible-stack-overflow-by-recursive-shrinker-calls.patch >>>>>> drm-ttm-pass-gfp-flags-in-order-to-avoid-deadlock.patch >>>>>> drm-ttm-use-mutex_trylock-to-avoid-deadlock-inside-shrinker-functions.patch >>>>> Thanks for info, Chuck. >>>>> >>>>> Unfortunately, none of these fix TTM dma allocation doing CMA dma >>>>> allocation, >>>>> which is the root problem. >>>>> >>>>> Regards, >>>>> Peter Hurley >>>> The problem is not really in TTM but in CMA, There was a guy offering to >>>> fix this in the CMA code but I guess he didn't probably because he >>>> didn't receive any feedback. >>>> >>> Yeah, the "solution" to this problem seems to be "don't enable CMA on >>> x86". Maybe it should even be disabled in the config system. >> Or, as previously suggested, don't use CMA for order 0 (single page) >> allocations.... > On devices that actually need CMA pools to arrange for memory to be in > certain ranges, I think you probably do want to have order 0 pages > come from the CMA pool.
But can the DMA subsystem or more specifically dma_alloc_coherent() really guarantee such things? Isn't it better for such devices to use CMA directly? /Thomas > > Seems like disabling CMA on x86 (where it should be unneeded) is the > better way, IMO > > BR, > -R > > >> /Thomas >> >> _______________________________________________ >> dri-devel mailing list >> [email protected] >> https://urldefense.proofpoint.com/v1/url?u=http://lists.freedesktop.org/mailman/listinfo/dri-devel&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=l5Ago9ekmVFZ3c4M6eauqrJWGwjf6fTb%2BP3CxbBFkVM%3D%0A&m=Uz7JXDXYXp4RlLs7G6qxMQlhOOT0trW3l78xpKg6Ass%3D%0A&s=50d6b7b3bfd093c93a228437a3d4414e49b4de817657c49c35154a115a5c2188 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
