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: Michal Hocko <mhocko@suse.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index de1c50b..15cab39 100644
--- a/include/linux/nodemask.h
+++ b/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 --git a/mm/oom_kill.c b/mm/oom_kill.c
index a501a0a..c86fbd1 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -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");
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8f2b9ad..7a19976 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -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();