From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, hughd@google.com, linux-mm@kvack.org,
mm-commits@vger.kernel.org, qcai@redhat.com,
stable@vger.kernel.org, torvalds@linux-foundation.org
Subject: [patch 06/12] mm/swapfile: do not sleep with a spin lock held
Date: Sat, 05 Dec 2020 22:14:55 -0800 [thread overview]
Message-ID: <20201206061455.fGLHX_jlo%akpm@linux-foundation.org> (raw)
In-Reply-To: <20201205221412.67f14b9b3a5ef531c76dd452@linux-foundation.org>
From: Qian Cai <qcai@redhat.com>
Subject: mm/swapfile: do not sleep with a spin lock held
We can't call kvfree() with a spin lock held, so defer it. Fixes a
might_sleep() runtime warning.
Link: https://lkml.kernel.org/r/20201202151549.10350-1-qcai@redhat.com
Fixes: 873d7bcfd066 ("mm/swapfile.c: use kvzalloc for swap_info_struct allocation")
Signed-off-by: Qian Cai <qcai@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/swapfile.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/swapfile.c~mm-swapfile-do-not-sleep-with-a-spin-lock-held
+++ a/mm/swapfile.c
@@ -2867,6 +2867,7 @@ late_initcall(max_swapfiles_check);
static struct swap_info_struct *alloc_swap_info(void)
{
struct swap_info_struct *p;
+ struct swap_info_struct *defer = NULL;
unsigned int type;
int i;
@@ -2895,7 +2896,7 @@ static struct swap_info_struct *alloc_sw
smp_wmb();
WRITE_ONCE(nr_swapfiles, nr_swapfiles + 1);
} else {
- kvfree(p);
+ defer = p;
p = swap_info[type];
/*
* Do not memset this entry: a racing procfs swap_next()
@@ -2908,6 +2909,7 @@ static struct swap_info_struct *alloc_sw
plist_node_init(&p->avail_lists[i], 0);
p->flags = SWP_USED;
spin_unlock(&swap_lock);
+ kvfree(defer);
spin_lock_init(&p->lock);
spin_lock_init(&p->cont_lock);
_
next prev parent reply other threads:[~2020-12-06 6:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 6:14 incoming Andrew Morton
2020-12-06 6:14 ` [patch 01/12] zlib: export S390 symbols for zlib modules Andrew Morton
2020-12-07 9:03 ` Zaslonko Mikhail
2020-12-08 0:45 ` Randy Dunlap
2020-12-08 8:19 ` Zaslonko Mikhail
2020-12-18 22:18 ` Randy Dunlap
2020-12-06 6:14 ` [patch 02/12] coredump: fix core_pattern parse error Andrew Morton
2020-12-06 6:14 ` [patch 03/12] mm: memcg/slab: fix obj_cgroup_charge() return value handling Andrew Morton
2020-12-06 6:14 ` [patch 04/12] mm: list_lru: set shrinker map bit when child nr_items is not zero Andrew Morton
2020-12-06 6:14 ` [patch 05/12] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING Andrew Morton
2020-12-06 6:14 ` Andrew Morton [this message]
2020-12-06 6:14 ` [patch 07/12] mailmap: add two more addresses of Uwe Kleine-König Andrew Morton
2020-12-06 6:15 ` [patch 08/12] tools/testing/selftests/vm: fix build error Andrew Morton
2020-12-06 6:15 ` [patch 09/12] userfaultfd: selftests: fix SIGSEGV if huge mmap fails Andrew Morton
2020-12-06 6:15 ` [patch 10/12] mm/filemap: add static for function __add_to_page_cache_locked Andrew Morton
2020-12-06 6:15 ` [patch 11/12] hugetlb_cgroup: fix offline of hugetlb cgroup with reservations Andrew Morton
2020-12-06 6:15 ` [patch 12/12] mm/mmap.c: fix mmap return value when vma is merged after call_mmap() Andrew Morton
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