From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yafang Shao Subject: [PATCH] mm: avoid bothering interrupted task when charge memcg in softirq Date: Sat, 14 Jul 2018 16:32:02 +0800 Message-ID: <1531557122-12540-1-git-send-email-laoar.shao@gmail.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Akf5sLt8347RHVY+scAnPDa1ovmW923VlqnFnICc500=; b=urtRXWaM4QG2OkH5hzq0uiTLDIL43VY6FuA6MHz191bAZLEF8HbzrtRkY0Gas3f9ck w/jWZ+GaX/B51oJO5hHpZLv4Pj0+kUv6yEVKaSOLy3HH20P3TMuHpr0Mm+/o7CYhWiGT CKPoxvD/wyDqZVOcWTRMk8DPwux9wuP62FY/L0ERhebYDM/RuQqNVVBleUFBdYjrb7tv ip/xzq2VEBHcjHjSq3kwYT7XXBRKGMdvtgOXyDk7oTyeciEvMvfWk7L4Vx4eBO+3OuAl zzmRM8vYTNQEYtyDVGnJo5Rne+5Lgz2bR+V+T+b3Xter3mZ69VkP9n8/kx99+gWnAqrk q/Iw== Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yafang Shao try_charge maybe executed in packet receive path, which is in interrupt context. In this situation, the 'current' is the interrupted task, which may has no relation to the rx softirq, So it is nonsense to use 'current'. Avoid bothering the interrupted if page_counter_try_charge failes. Signed-off-by: Yafang Shao --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 68ef266..13f95db 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2123,6 +2123,9 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, goto retry; } + if (in_softirq()) + goto nomem; + /* * Unlike in global OOM situations, memcg is not in a physical * memory shortage. Allow dying and OOM-killed tasks to -- 1.8.3.1