From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: [PATCH 5/5] fixup_pack_header_footer(): use nicely aligned buffer sizes Date: Fri, 29 Aug 2008 16:08:02 -0400 Message-ID: <1220040482-10108-6-git-send-email-nico@cam.org> References: <20080829143023.GA7403@spearce.org> <1220040482-10108-1-git-send-email-nico@cam.org> <1220040482-10108-2-git-send-email-nico@cam.org> <1220040482-10108-3-git-send-email-nico@cam.org> <1220040482-10108-4-git-send-email-nico@cam.org> <1220040482-10108-5-git-send-email-nico@cam.org> Content-Transfer-Encoding: 7BIT Cc: git@vger.kernel.org To: Junio C Hamano X-From: git-owner@vger.kernel.org Fri Aug 29 22:09:48 2008 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1KZAHz-0006Wv-7f for gcvg-git-2@gmane.org; Fri, 29 Aug 2008 22:09:47 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752409AbYH2UIe (ORCPT ); Fri, 29 Aug 2008 16:08:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752216AbYH2UIe (ORCPT ); Fri, 29 Aug 2008 16:08:34 -0400 Received: from relais.videotron.ca ([24.201.245.36]:15047 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752317AbYH2UIc (ORCPT ); Fri, 29 Aug 2008 16:08:32 -0400 Received: from localhost.localdomain ([66.131.194.97]) by VL-MO-MR005.ip.videotron.ca (Sun Java(tm) System Messaging Server 6.3-4.01 (built Aug 3 2007; 32bit)) with ESMTP id <0K6D007OOP8J18A0@VL-MO-MR005.ip.videotron.ca> for git@vger.kernel.org; Fri, 29 Aug 2008 16:07:33 -0400 (EDT) X-Mailer: git-send-email 1.6.0.1.212.g35f9f In-reply-to: <1220040482-10108-5-git-send-email-nico@cam.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: It should be more efficient to use nicely aligned buffer sizes, either for filesystem operations or SHA1 checksums. Also, using a relatively small nominal size might allow for the data to remain in L1 cache between both SHA1_Update() calls. Signed-off-by: Nicolas Pitre --- pack-write.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/pack-write.c b/pack-write.c index f9776c5..939ed56 100644 --- a/pack-write.c +++ b/pack-write.c @@ -167,7 +167,7 @@ void fixup_pack_header_footer(int pack_fd, unsigned char *partial_pack_sha1, off_t partial_pack_offset) { - static const int buf_sz = 128 * 1024; + int aligned_sz, buf_sz = 8 * 1024; SHA_CTX old_sha1_ctx, new_sha1_ctx; struct pack_header hdr; char *buf; @@ -188,10 +188,11 @@ void fixup_pack_header_footer(int pack_fd, partial_pack_offset -= sizeof(hdr); buf = xmalloc(buf_sz); + aligned_sz = buf_sz - sizeof(hdr); for (;;) { ssize_t m, n; - m = (partial_pack_sha1 && partial_pack_offset < buf_sz) ? - partial_pack_offset : buf_sz; + m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ? + partial_pack_offset : aligned_sz; n = xread(pack_fd, buf, m); if (!n) break; @@ -199,6 +200,10 @@ void fixup_pack_header_footer(int pack_fd, die("Failed to checksum %s: %s", pack_name, strerror(errno)); SHA1_Update(&new_sha1_ctx, buf, n); + aligned_sz -= n; + if (!aligned_sz) + aligned_sz = buf_sz; + if (!partial_pack_sha1) continue; -- 1.6.0.1.212.g35f9f