On Fri, Mar 23, 2018 at 4:38 PM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > On Fri 23-03-18 15:57:32, Zhaoyang Huang wrote: >> For the type of 'ALLOC_HARDER' page allocation, there is an express >> highway for the whole process which lead the allocation reach __rmqueue_xxx >> easier than other type. >> However, when CMA is enabled, the free_page within zone_watermark_ok() will >> be deducted for number the pages in CMA type, which may cause the watermark >> check fail, but there are possible enough HighAtomic or Unmovable and >> Reclaimable pages in the zone. So add 'alloc_harder' here to >> count CMA pages in to clean the obstacles on the way to the final. > > This is no longer the case in the current mmotm tree. Have a look at > Joonsoo's zone movable based CMA patchset http://lkml.kernel.org/r/1512114786-5085-1-git-send-email-iamjoonsoo.kim@xxxxxxx > Thanks for the information. However, I can't find the commit in the latest mainline, is it merged? >> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxxxxxx> >> --- >> mm/page_alloc.c | 7 +++++-- >> 1 file changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 635d7dd..cc18620 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -3045,8 +3045,11 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, >> >> >> #ifdef CONFIG_CMA >> - /* If allocation can't use CMA areas don't use free CMA pages */ >> - if (!(alloc_flags & ALLOC_CMA)) >> + /* >> + * If allocation can't use CMA areas and no alloc_harder set for none >> + * order0 allocation, don't use free CMA pages. >> + */ >> + if (!(alloc_flags & ALLOC_CMA) && (!alloc_harder || !order)) >> free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); >> #endif >> >> -- >> 1.9.1 >> > > -- > Michal Hocko > SUSE Labs
