Commit 0205f755 authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

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@perches.com

[akpm@linux-foundation.org: fix tile warning, per Arnd]
Link: http://lkml.kernel.org/r/20171109100531.3cn2hcqnuj7mjaju@dhcp22.suse.cz


Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarJoe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c50842c8

include/linux/nodemask.h

+3 −1
Original line number Diff line number Diff line
@@ -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

mm/oom_kill.c

+4 −8
Original line number Diff line number Diff line
@@ -426,14 +426,10 @@ static void dump_tasks(struct mem_cgroup *memcg, const nodemask_t *nodemask) 


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");

mm/page_alloc.c

+3 −9
Original line number Diff line number Diff line
@@ -3279,20 +3279,14 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...) 
	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();

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