From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932621AbcHKVGZ (ORCPT ); Thu, 11 Aug 2016 17:06:25 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:58152 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932444AbcHKVGW (ORCPT ); Thu, 11 Aug 2016 17:06:22 -0400 Date: Thu, 11 Aug 2016 23:06:15 +0200 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Linux PM list , Linux Kernel Mailing List Subject: Re: [PATCH v2 3/3] PM / hibernate: Recycle safe pages after image restoration Message-ID: <20160811210615.GA28618@amd> References: <2260927.OOWMYX738E@vostro.rjw.lan> <2448424.sR3JM3oiG3@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2448424.sR3JM3oiG3@vostro.rjw.lan> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > From: Rafael J. Wysocki > > One of the memory bitmaps used by the hibernation image restoration > code is freed after the image has been loaded. > > That is not quite efficient, though, because the memory pages used > for building that bitmap are known to be safe (ie. they were not > used by the image kernel before hibernation) and the arch-specific > code finalizing the image restoration may need them. In that case > it needs to allocate those pages again via the memory management > subsystem, check if they are really safe again by consulting the > other bitmaps and so on. > > To avoid that, recycle those pages by putting them into the global > list of known safe pages so that they can be given to the arch code > right away when necessary. Ok, so you are trying to gain speed here? How much is the speedup? Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html