From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Yu Zhao <yuzhao@google.com>
Cc: Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: avoid slub allocation while holding list_lock
Date: Mon, 9 Sep 2019 19:00:52 +0300 [thread overview]
Message-ID: <20190909160052.cxpfdmnrqucsilz2@box> (raw)
In-Reply-To: <20190909061016.173927-1-yuzhao@google.com>
On Mon, Sep 09, 2019 at 12:10:16AM -0600, Yu Zhao wrote:
> If we are already under list_lock, don't call kmalloc(). Otherwise we
> will run into deadlock because kmalloc() also tries to grab the same
> lock.
>
> Instead, allocate pages directly. Given currently page->objects has
> 15 bits, we only need 1 page. We may waste some memory but we only do
> so when slub debug is on.
>
> WARNING: possible recursive locking detected
> --------------------------------------------
> mount-encrypted/4921 is trying to acquire lock:
> (&(&n->list_lock)->rlock){-.-.}, at: ___slab_alloc+0x104/0x437
>
> but task is already holding lock:
> (&(&n->list_lock)->rlock){-.-.}, at: __kmem_cache_shutdown+0x81/0x3cb
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(&(&n->list_lock)->rlock);
> lock(&(&n->list_lock)->rlock);
>
> *** DEADLOCK ***
>
> Signed-off-by: Yu Zhao <yuzhao@google.com>
Looks sane to me:
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
--
Kirill A. Shutemov
next prev parent reply other threads:[~2019-09-09 16:00 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 6:10 [PATCH] mm: avoid slub allocation while holding list_lock Yu Zhao
2019-09-09 16:00 ` Kirill A. Shutemov [this message]
[not found] ` <e5e25aa3-651d-92b4-ac82-c5011c66a7cb@I-love.SAKURA.ne.jp>
2019-09-09 21:39 ` Yu Zhao
[not found] ` <201909100141.x8A1fVdu048305@www262.sakura.ne.jp>
2019-09-10 2:16 ` Yu Zhao
2019-09-10 9:16 ` Kirill A. Shutemov
2019-09-11 14:13 ` Andrew Morton
2019-09-12 0:29 ` [PATCH 1/3] mm: correct mask size for slub page->objects Yu Zhao
2019-09-12 0:29 ` [PATCH 2/3] mm: avoid slub allocation while holding list_lock Yu Zhao
2019-09-12 0:44 ` Kirill A. Shutemov
2019-09-12 1:31 ` Yu Zhao
2019-09-12 2:31 ` [PATCH v2 1/4] mm: correct mask size for slub page->objects Yu Zhao
2019-09-12 2:31 ` [PATCH v2 2/4] mm: clean up validate_slab() Yu Zhao
2019-09-12 9:46 ` Kirill A. Shutemov
2019-09-12 2:31 ` [PATCH v2 3/4] mm: avoid slub allocation while holding list_lock Yu Zhao
2019-09-12 10:04 ` Kirill A. Shutemov
2019-09-12 2:31 ` [PATCH v2 4/4] mm: lock slub page when listing objects Yu Zhao
2019-09-12 10:06 ` Kirill A. Shutemov
2019-09-12 21:12 ` Yu Zhao
2019-09-13 14:58 ` Christopher Lameter
2019-09-12 9:40 ` [PATCH v2 1/4] mm: correct mask size for slub page->objects Kirill A. Shutemov
2019-09-12 21:11 ` Yu Zhao
2019-09-12 22:03 ` Kirill A. Shutemov
2019-09-14 0:07 ` [PATCH v3 1/2] mm: clean up validate_slab() Yu Zhao
2019-09-14 0:07 ` [PATCH v3 2/2] mm: avoid slub allocation while holding list_lock Yu Zhao
2019-09-16 8:39 ` [PATCH v3 1/2] mm: clean up validate_slab() Kirill A. Shutemov
2019-11-08 19:39 ` [PATCH v4 " Yu Zhao
2019-11-08 19:39 ` [PATCH v4 2/2] mm: avoid slub allocation while holding list_lock Yu Zhao
2019-11-09 20:52 ` Christopher Lameter
2019-11-09 23:01 ` Yu Zhao
2019-11-09 23:16 ` Christopher Lameter
2019-11-10 18:47 ` Yu Zhao
2019-11-11 15:47 ` Christopher Lameter
2019-11-11 15:55 ` [FIX] slub: Remove kmalloc under list_lock from list_slab_objects() V2 Christopher Lameter
2019-11-30 23:09 ` Andrew Morton
2019-12-02 15:12 ` Christopher Lameter
2019-12-07 22:03 ` Yu Zhao
2020-01-10 14:11 ` Vlastimil Babka
[not found] ` <e0ed44ae-8dae-e8db-9d14-2b09b239af8e@i-love.sakura.ne.jp>
2020-01-13 1:34 ` Christopher Lameter
2019-11-11 18:15 ` [PATCH v4 2/2] mm: avoid slub allocation while holding list_lock Shakeel Butt
2019-09-12 0:29 ` [PATCH 3/3] mm: lock slub page when listing objects Yu Zhao
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