From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f41.google.com (mail-la0-f41.google.com [209.85.215.41]) by kanga.kvack.org (Postfix) with ESMTP id A9B456B0256 for ; Mon, 14 Sep 2015 08:51:27 -0400 (EDT) Received: by lahg1 with SMTP id g1so56128948lah.1 for ; Mon, 14 Sep 2015 05:51:26 -0700 (PDT) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id q9si3758608laj.173.2015.09.14.05.51.25 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Sep 2015 05:51:26 -0700 (PDT) Date: Mon, 14 Sep 2015 15:51:11 +0300 From: Vladimir Davydov Subject: Re: [PATCH 3/3] memcg: drop unnecessary cold-path tests from __memcg_kmem_bypass() Message-ID: <20150914125111.GF30743@esperanza> References: <20150913201416.GC25369@htj.duckdns.org> <20150913201442.GD25369@htj.duckdns.org> <20150913201509.GE25369@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20150913201509.GE25369@htj.duckdns.org> Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com On Sun, Sep 13, 2015 at 04:15:09PM -0400, Tejun Heo wrote: > __memcg_kmem_bypass() decides whether a kmem allocation should be > bypassed to the root memcg. Some conditions that it tests are valid > criteria regarding who should be held accountable; however, there are > a couple unnecessary tests for cold paths - __GFP_FAIL and > fatal_signal_pending(). > > The previous patch updated try_charge() to handle both __GFP_FAIL and > dying tasks correctly and the only thing these two tests are doing is > making accounting less accurate and sprinkling tests for cold path > conditions in the hot paths. There's nothing meaningful gained by > these extra tests. > > This patch removes the two unnecessary tests from > __memcg_kmem_bypass(). > > Signed-off-by: Tejun Heo Reviewed-by: Vladimir Davydov -- 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/ . Don't email: email@kvack.org