linux-rt-users.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Liwei Song <liwei.song@windriver.com>
Cc: linux-rt <linux-rt-users@vger.kernel.org>,
	Mike Galbraith <efault@gmx.de>
Subject: [PATCH RT] mm: Don't warn about atomic memory allocations during suspend
Date: Mon, 4 May 2020 16:53:25 +0200	[thread overview]
Message-ID: <20200504145325.3rjc3iskg2coejje@linutronix.de> (raw)
In-Reply-To: <0662fa80-3dbd-3b47-3677-f22716f5661f@windriver.com>

From: Liwei Song <liwei.song@windriver.com>

The ACPI code allocates larger amount of memory during resume. This
triggers a warning because the allocation happens with disabled
interrupts.
At this stage only one CPU is active so there should be no lock
contention. If SLUB needs to call into the buddy allocator for more
memory then it should not enable interrupts.

Limit the check to system state with more CPUs and scheduling and only
enable interrupts in SLUB at this stage.

Signed-off-by: Liwei Song <liwei.song@windriver.com>
[bigeasy: commit description, allocate_slab() hunk]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---

Are you okay with this Liwei?

 mm/slub.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 15c194ff16e6e..6ea1057edf1ab 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1655,7 +1655,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 		enableirqs = true;
 
 #ifdef CONFIG_PREEMPT_RT
-	if (system_state > SYSTEM_BOOTING)
+	if (system_state > SYSTEM_BOOTING && system_state < SYSTEM_SUSPEND)
 		enableirqs = true;
 #endif
 	if (enableirqs)
@@ -2771,7 +2771,8 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
 	unsigned long tid;
 
 	if (IS_ENABLED(CONFIG_PREEMPT_RT) && IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP))
-		WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING);
+		WARN_ON_ONCE(!preemptible() &&
+			     (system_state > SYSTEM_BOOTING && system_state < SYSTEM_SUSPEND));
 
 	s = slab_pre_alloc_hook(s, gfpflags);
 	if (!s)
@@ -3236,7 +3237,8 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	int i;
 
 	if (IS_ENABLED(CONFIG_PREEMPT_RT) && IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP))
-		WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING);
+		WARN_ON_ONCE(!preemptible() &&
+			     (system_state > SYSTEM_BOOTING && system_state < SYSTEM_SUSPEND));
 
 	/* memcg and kmem_cache debug support */
 	s = slab_pre_alloc_hook(s, flags);
-- 
2.26.2


  reply	other threads:[~2020-05-04 14:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-13  4:18 [PATCH RT] mm: do not warn for suspend when allocate memory on RT Liwei Song
2020-04-16 17:09 ` Sebastian Andrzej Siewior
2020-04-17  2:50   ` Liwei Song
2020-04-21 14:51     ` Sebastian Andrzej Siewior
2020-04-24  9:09       ` Liwei Song
2020-05-04 14:53         ` Sebastian Andrzej Siewior [this message]
2020-05-05  3:59           ` [PATCH RT] mm: Don't warn about atomic memory allocations during suspend Liwei Song

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200504145325.3rjc3iskg2coejje@linutronix.de \
    --to=bigeasy@linutronix.de \
    --cc=efault@gmx.de \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=liwei.song@windriver.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).