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[195.135.220.15]) by mx.google.com with ESMTPS id t28si1447091eda.100.2019.03.01.07.26.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Mar 2019 07:26:17 -0800 (PST) Received-SPF: pass (google.com: domain of metan@suse.de designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of metan@suse.de designates 195.135.220.15 as permitted sender) smtp.mailfrom=metan@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 22603AB4D; Fri, 1 Mar 2019 15:26:17 +0000 (UTC) Date: Fri, 1 Mar 2019 16:25:48 +0100 From: Cyril Hrubis To: Vlastimil Babka Cc: Oscar Salvador , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, hughd@google.com, kirill@shutemov.name, joel@joelfernandes.org, jglisse@redhat.com, yang.shi@linux.alibaba.com, mgorman@techsingularity.net Subject: Re: [PATCH] mm,mremap: Bail out earlier in mremap_to under map pressure Message-ID: <20190301152547.GA25732@rei> References: <20190226091314.18446-1-osalvador@suse.de> <20190226140428.3e7c8188eda6a54f9da08c43@linux-foundation.org> <20190227213205.5wdjucqdgfqx33tr@d104.suse.de> <5edcfeb8-4f53-0fe6-1e5b-c1e485f91d0d@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5edcfeb8-4f53-0fe6-1e5b-c1e485f91d0d@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi! > Hopefully the only program that would start failing would be a LTP test > testing the current behavior near the limit (if such test exists). And > that can be adjusted. There does not seem to be a mremap() test that would do such a thing, so we should be safe :-). BTW there was a similar fix for mmap() with MAP_FIXED that caused a LTP test to fail and was fixed in: commit e8420a8ece80b3fe810415ecf061d54ca7fab266 Author: Cyril Hrubis Date: Mon Apr 29 15:08:33 2013 -0700 mm/mmap: check for RLIMIT_AS before unmapping And I haven't heard of any breakages so far so I guess that this very similar situation and that the possibility of breaking real world applications here is really low. -- Cyril Hrubis chrubis@suse.cz