From: David Rientjes <rientjes@xxxxxxxxxx> Subject: mm, page_alloc: warn_alloc nodemask is NULL when cpusets are disabled The patch "mm, page_alloc: warn_alloc print nodemask" implicitly sets the allocation nodemask to cpuset_current_mems_allowed when there is no effective mempolicy. cpuset_current_mems_allowed is only effective when cpusets are enabled, which is also printed by warn_alloc(), so setting the nodemask to cpuset_current_mems_allowed is redundant and prevents debugging issues where ac->nodemask is not set properly in the page allocator. This provides better debugging output since cpuset_print_current_mems_allowed() is already provided. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701181347320.142399@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff -puN mm/page_alloc.c~mm-page_alloc-warn_alloc-nodemask-is-null-when-cpusets-are-disabled mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-warn_alloc-nodemask-is-null-when-cpusets-are-disabled +++ a/mm/page_alloc.c @@ -3034,7 +3034,6 @@ void warn_alloc(gfp_t gfp_mask, nodemask va_list args; static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); - nodemask_t *nm = (nodemask) ? nodemask : &cpuset_current_mems_allowed; if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) || debug_guardpage_minorder() > 0) @@ -3048,11 +3047,16 @@ void warn_alloc(gfp_t gfp_mask, nodemask pr_cont("%pV", &vaf); va_end(args); - pr_cont(", mode:%#x(%pGg), nodemask=%*pbl\n", gfp_mask, &gfp_mask, nodemask_pr_args(nm)); + pr_cont(", mode:%#x(%pGg), nodemask=", gfp_mask, &gfp_mask); + if (nodemask) + pr_cont("%*pbl\n", nodemask_pr_args(nodemask)); + else + pr_cont("(null)\n"); + cpuset_print_current_mems_allowed(); dump_stack(); - warn_alloc_show_mem(gfp_mask, nm); + warn_alloc_show_mem(gfp_mask, nodemask); } static inline struct page * _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
