From: Hailong liu <liu.hailong6@xxxxxxxxxx> Subject: mm/page_alloc: add a missing mm_page_alloc_zone_locked() tracepoint The trace point *trace_mm_page_alloc_zone_locked()* in __rmqueue() does not currently cover all branches. Add the missing tracepoint and check the page before do that. [akpm@xxxxxxxxxxxxxxxxxxxx: use IS_ENABLED() to suppress warning] Link: https://lkml.kernel.org/r/20201228132901.41523-1-carver4lio@xxxxxxx Signed-off-by: Hailong liu <liu.hailong6@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-add-a-missing-mm_page_alloc_zone_locked-tracepoint +++ a/mm/page_alloc.c @@ -2862,20 +2862,20 @@ __rmqueue(struct zone *zone, unsigned in { struct page *page; -#ifdef CONFIG_CMA - /* - * Balance movable allocations between regular and CMA areas by - * allocating from CMA when over half of the zone's free memory - * is in the CMA area. - */ - if (alloc_flags & ALLOC_CMA && - zone_page_state(zone, NR_FREE_CMA_PAGES) > - zone_page_state(zone, NR_FREE_PAGES) / 2) { - page = __rmqueue_cma_fallback(zone, order); - if (page) - return page; + if (IS_ENABLED(CONFIG_CMA)) { + /* + * Balance movable allocations between regular and CMA areas by + * allocating from CMA when over half of the zone's free memory + * is in the CMA area. + */ + if (alloc_flags & ALLOC_CMA && + zone_page_state(zone, NR_FREE_CMA_PAGES) > + zone_page_state(zone, NR_FREE_PAGES) / 2) { + page = __rmqueue_cma_fallback(zone, order); + if (page) + goto out; + } } -#endif retry: page = __rmqueue_smallest(zone, order, migratetype); if (unlikely(!page)) { @@ -2886,8 +2886,9 @@ retry: alloc_flags)) goto retry; } - - trace_mm_page_alloc_zone_locked(page, order, migratetype); +out: + if (page) + trace_mm_page_alloc_zone_locked(page, order, migratetype); return page; } _
