Hi Laura, On Tuesday, June 05, 2012 9:27 PM Laura Abbott wrote:
> Currently, when freeing 0 order pages, CMA pages are treated > the same as regular movable pages, which means they end up > on the per-cpu page list. This means that the CMA pages are > likely to be allocated for something other than contigous > memory. This increases the chance that the next alloc_contig_range > will fail because pages can't be migrated. > > Given the size of the CMA region is typically limited, it is best to > optimize for success of alloc_contig_range as much as possible. > Do this by freeing CMA pages directly instead of putting them > on the per-cpu page lists. > > Signed-off-by: Laura Abbott <[email protected]> > --- > mm/page_alloc.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 0e1c6f5..c9a6483 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1310,7 +1310,8 @@ void free_hot_cold_page(struct page *page, int cold) > * excessively into the page allocator > */ > if (migratetype >= MIGRATE_PCPTYPES) { > - if (unlikely(migratetype == MIGRATE_ISOLATE)) { > + if (unlikely(migratetype == MIGRATE_ISOLATE) > + || is_migrate_cma(migratetype)) { > free_one_page(zone, page, 0, migratetype); > goto out; > } > -- Well this patch has some side effects, in some cases it might force kernel to consume regular movable pages which should be left as a fallback for critical non-movable allocations. Do you have any statistics for the change introduced by this patch? Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
