From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm: simplify nodemask printing alloc_warn() and dump_header() have to explicitly handle NULL nodemask which forces both paths to use pr_cont. We can do better. printk already handles NULL pointers properly so all we need is to teach nodemask_pr_args to handle NULL nodemask carefully. This allows simplification of both alloc_warn() and dump_header() and gets rid of pr_cont altogether. This patch has been motivated by patch from Joe Perches http://lkml.kernel.org/r/b31236dfe3fc924054fd7842bde678e71d193638.1509991345.git.joe@xxxxxxxxxxx [akpm@xxxxxxxxxxxxxxxxxxxx: fix tile warning, per Arnd] Link: http://lkml.kernel.org/r/20171109100531.3cn2hcqnuj7mjaju@xxxxxxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Joe Perches <joe@xxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/nodemask.h | 4 +++- mm/oom_kill.c | 12 ++++-------- mm/page_alloc.c | 12 +++--------- 3 files changed, 10 insertions(+), 18 deletions(-) diff -puN include/linux/nodemask.h~mm-simplify-nodemask-printing include/linux/nodemask.h --- a/include/linux/nodemask.h~mm-simplify-nodemask-printing +++ a/include/linux/nodemask.h @@ -104,7 +104,9 @@ extern nodemask_t _unused_nodemask_arg_; * * Can be used to provide arguments for '%*pb[l]' when printing a nodemask. */ -#define nodemask_pr_args(maskp) MAX_NUMNODES, (maskp)->bits +#define nodemask_pr_args(maskp) \ + ((maskp) != NULL) ? MAX_NUMNODES : 0, \ + ((maskp) != NULL) ? (maskp)->bits : NULL /* * The inline keyword gives the compiler room to decide to inline, or diff -puN mm/oom_kill.c~mm-simplify-nodemask-printing mm/oom_kill.c --- a/mm/oom_kill.c~mm-simplify-nodemask-printing +++ a/mm/oom_kill.c @@ -426,14 +426,10 @@ static void dump_tasks(struct mem_cgroup static void dump_header(struct oom_control *oc, struct task_struct *p) { - pr_warn("%s invoked oom-killer: gfp_mask=%#x(%pGg), nodemask=", - current->comm, oc->gfp_mask, &oc->gfp_mask); - if (oc->nodemask) - pr_cont("%*pbl", nodemask_pr_args(oc->nodemask)); - else - pr_cont("(null)"); - pr_cont(", order=%d, oom_score_adj=%hd\n", - oc->order, current->signal->oom_score_adj); + pr_warn("%s invoked oom-killer: gfp_mask=%#x(%pGg), nodemask=%*pbl, order=%d, oom_score_adj=%hd\n", + current->comm, oc->gfp_mask, &oc->gfp_mask, + nodemask_pr_args(oc->nodemask), oc->order, + current->signal->oom_score_adj); if (!IS_ENABLED(CONFIG_COMPACTION) && oc->order) pr_warn("COMPACTION is disabled!!!\n"); diff -puN mm/page_alloc.c~mm-simplify-nodemask-printing mm/page_alloc.c --- a/mm/page_alloc.c~mm-simplify-nodemask-printing +++ a/mm/page_alloc.c @@ -3279,20 +3279,14 @@ void warn_alloc(gfp_t gfp_mask, nodemask if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) return; - pr_warn("%s: ", current->comm); - va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; - pr_cont("%pV", &vaf); + pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl\n", + current->comm, &vaf, gfp_mask, &gfp_mask, + nodemask_pr_args(nodemask)); va_end(args); - 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(); _ -- 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
