From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10451 Path: news.gmane.org!.POSTED!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: Re: [J-core] Aligned copies and cacheline conflicts? Date: Wed, 14 Sep 2016 22:36:45 -0400 Message-ID: <20160915023644.GD15995@brightrain.aerifal.cx> References: <0c256cb1-d0fa-9a5a-3976-b7ef545c1827@landley.net> <20160915003451.GC15995@brightrain.aerifal.cx> <8498eaa7-f263-efc8-a59c-d601e84af2db@landley.net> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1473907025 32072 195.159.176.226 (15 Sep 2016 02:37:05 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 15 Sep 2016 02:37:05 +0000 (UTC) User-Agent: Mutt/1.5.21 (2010-09-15) Cc: "j-core@j-core.org" , musl@lists.openwall.com To: Rob Landley Original-X-From: musl-return-10464-gllmg-musl=m.gmane.org@lists.openwall.com Thu Sep 15 04:37:01 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1bkMXt-0007uL-E6 for gllmg-musl@m.gmane.org; Thu, 15 Sep 2016 04:37:01 +0200 Original-Received: (qmail 3253 invoked by uid 550); 15 Sep 2016 02:37:01 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 3235 invoked from network); 15 Sep 2016 02:37:00 -0000 Content-Disposition: inline In-Reply-To: <8498eaa7-f263-efc8-a59c-d601e84af2db@landley.net> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:10451 Archived-At: On Wed, Sep 14, 2016 at 07:58:52PM -0500, Rob Landley wrote: > On 09/14/2016 07:34 PM, Rich Felker wrote: > > I could put a fork of memcpy.c in sh/memcpy.c and work on it there and > > only merge it back to the shared one if others test it on other archs > > and find it beneficial (or at least not harmful). > > Both musl and the kernel need it. And yes at the moment it seems > architecture-specific, but it's a _big_ performance difference... I actually think it's justifiable to have in the generic C memcpy, from a standpoint that the generic C shouldn't assume an N-way (N>1, i.e. not direct mapped) associative cache. Just need to make sure changing it doesn't make gcc do something utterly idiotic for other archs, I guess. I'll take a look at this. Rich