From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from s3.sipsolutions.net ([2a01:4f8:191:4433::2] helo=sipsolutions.net) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1knoeH-0000pv-AW for linux-um@lists.infradead.org; Fri, 11 Dec 2020 20:04:18 +0000 Message-ID: <580fe708174c7daf90e8a3d68c0487a1e9aa434d.camel@sipsolutions.net> Subject: Re: [PATCH v4 1/7] um: allow the use of glibc functions instead of builtins From: Johannes Berg Date: Fri, 11 Dec 2020 21:03:53 +0100 In-Reply-To: <20201211174559.26010-2-anton.ivanov@cambridgegreys.com> References: <20201211174559.26010-1-anton.ivanov@cambridgegreys.com> <20201211174559.26010-2-anton.ivanov@cambridgegreys.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: anton.ivanov@cambridgegreys.com, linux-um@lists.infradead.org Cc: richard@nod.at On Fri, 2020-12-11 at 17:45 +0000, anton.ivanov@cambridgegreys.com wrote: > From: Anton Ivanov > > The UML kernel runs as a normal userspace process and can use most > of glibc string.h functionality instead of built-ins. At present, > when using built-ins, it is also limited to their unoptimized > versions, because it does not have the runtime code patching present > on x86 via apply_alternatives() > > Allowing the use of glibc for memcpy, memmove, etc provides 1-5% > boost on common file io as measured by cat and dd. The size of > the linux executable is also reduced by ~10KBytes. > > It is possible to turn this on/off via the kernel configuration. > > Signed-off-by: Anton Ivanov Reviewed-by: Johannes Berg johannes _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um