From: Hugh Dickins <hughd@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>, linux-mm@kvack.org
Subject: [PATCH] mm: fix UP THP spin_is_locked BUGs
Date: Tue, 7 Feb 2012 16:00:46 -0800 (PST) [thread overview]
Message-ID: <alpine.LSU.2.00.1202071556460.7549@eggly.anvils> (raw)
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.
asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.
Signed-off-by: Hugh Dickins <hughd@google.com>
---
mm/huge_memory.c | 4 ++--
mm/swap.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
--- 3.3-rc2/mm/huge_memory.c 2012-01-20 08:42:35.304020840 -0800
+++ linux/mm/huge_memory.c 2012-02-07 15:37:18.581666053 -0800
@@ -2083,7 +2083,7 @@ static void collect_mm_slot(struct mm_sl
{
struct mm_struct *mm = mm_slot->mm;
- VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
if (khugepaged_test_exit(mm)) {
/* free mm_slot */
@@ -2113,7 +2113,7 @@ static unsigned int khugepaged_scan_mm_s
int progress = 0;
VM_BUG_ON(!pages);
- VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock));
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
if (khugepaged_scan.mm_slot)
mm_slot = khugepaged_scan.mm_slot;
--- 3.3-rc2/mm/swap.c 2012-01-20 08:42:35.324020840 -0800
+++ linux/mm/swap.c 2012-02-07 15:37:18.581666053 -0800
@@ -659,7 +659,7 @@ void lru_add_page_tail(struct zone* zone
VM_BUG_ON(!PageHead(page));
VM_BUG_ON(PageCompound(page_tail));
VM_BUG_ON(PageLRU(page_tail));
- VM_BUG_ON(!spin_is_locked(&zone->lru_lock));
+ VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&zone->lru_lock));
SetPageLRU(page_tail);
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next reply other threads:[~2012-02-08 0:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-08 0:00 Hugh Dickins [this message]
2012-02-08 0:12 ` Andrew Morton
2012-02-08 0:33 ` Hugh Dickins
2012-02-08 2:35 ` Andrew Morton
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=alpine.LSU.2.00.1202071556460.7549@eggly.anvils \
--to=hughd@google.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-mm@kvack.org \
/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