From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C54E24503E for ; Mon, 19 May 2025 06:32:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747636342; cv=none; b=Y1ANsYKNT0r0fSKnc4tnPptVXcfbHa6sv7alrvNiDrddW9+RR2kMry6e+5p0773B1gGDr/WE3heremRG8FomBI9QORcBeQ/GGoxkIAAt9PHbOVJCFP92FeUKO1yn/0n5p9Y/cMe7q4og15f21bjls5y5Kr7/7lRomd//efv7ynU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747636342; c=relaxed/simple; bh=/jQh79tAgtQJLtj+eNyK2IrGdLJQsJ6BkRvDCw707AQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TMDJrobOFJPxdnzdWuCZbhiR0VscO91UeCz5LtrJwMqsVWl0KqMdzQAK3r1nPOgrC0GF3tdLWBGt/5EFXyZE1kIhbF/NOYlDh8mwrKSNF1Z49mJVs5HB/G1WjdHEhevXnrEhd/lpCzprPGkOYHftXDBhEOrpKd7rReZtc7aVEwc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=LOpPqdGw; arc=none smtp.client-ip=95.215.58.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="LOpPqdGw" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1747636329; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N4FZldpF4GqktzniwkIkdN9+wQAuTiNO6J7GT2TDHJM=; b=LOpPqdGwVTtIP0zbqyv0THgRp28es+d9NT9WIwpXgEYTvlXV4mQIB6Qk+B83teJozFhY72 zuoQHmP1oW5upj8znNJGuMDX4O2BCkgKW4snGWa7YoRSAUKeXZFt7ej9Qungt/YyTUGtPq jQE+hdenHiYUJ/jG03tvDzsaE8s385s= From: Shakeel Butt To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Vlastimil Babka , Alexei Starovoitov , Sebastian Andrzej Siewior , Harry Yoo , Yosry Ahmed , Peter Zijlstra , Mathieu Desnoyers , Tejun Heo , bpf@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team Subject: [PATCH v4 1/5] memcg: disable kmem charging in nmi for unsupported arch Date: Sun, 18 May 2025 23:31:38 -0700 Message-ID: <20250519063142.111219-2-shakeel.butt@linux.dev> In-Reply-To: <20250519063142.111219-1-shakeel.butt@linux.dev> References: <20250519063142.111219-1-shakeel.butt@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT The memcg accounting and stats uses this_cpu* and atomic* ops. There are archs which define CONFIG_HAVE_NMI but does not define CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS and ARCH_HAVE_NMI_SAFE_CMPXCHG, so memcg accounting for such archs in nmi context is not possible to support. Let's just disable memcg accounting in nmi context for such archs. Signed-off-by: Shakeel Butt --- init/Kconfig | 7 +++++++ mm/memcontrol.c | 3 +++ 2 files changed, 10 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 4cdd1049283c..a2aa49cfb8bd 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1006,6 +1006,13 @@ config MEMCG help Provides control over the memory footprint of tasks in a cgroup. +config MEMCG_NMI_UNSAFE + bool + depends on MEMCG + depends on HAVE_NMI + depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG + default y + config MEMCG_V1 bool "Legacy cgroup v1 memory controller" depends on MEMCG diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e17b698f6243..532e2c06ea60 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2652,6 +2652,9 @@ __always_inline struct obj_cgroup *current_obj_cgroup(void) struct mem_cgroup *memcg; struct obj_cgroup *objcg; + if (IS_ENABLED(CONFIG_MEMCG_NMI_UNSAFE) && in_nmi()) + return NULL; + if (in_task()) { memcg = current->active_memcg; if (unlikely(memcg)) -- 2.47.1