From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Turner Subject: [PATCH] read-cache: increase write buffer size Date: Fri, 18 Mar 2016 21:19:01 -0400 Message-ID: <1458350341-12276-1-git-send-email-dturner@twopensource.com> Cc: David Turner To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Sat Mar 19 02:19:19 2016 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ah5Xz-0006kz-6t for gcvg-git-2@plane.gmane.org; Sat, 19 Mar 2016 02:19:19 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754575AbcCSBTP (ORCPT ); Fri, 18 Mar 2016 21:19:15 -0400 Received: from mail-qg0-f41.google.com ([209.85.192.41]:34538 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753243AbcCSBTO (ORCPT ); Fri, 18 Mar 2016 21:19:14 -0400 Received: by mail-qg0-f41.google.com with SMTP id w104so114805316qge.1 for ; Fri, 18 Mar 2016 18:19:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=twopensource-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=XGAUzDlnngJw9tt7CGYwHPVIc1CqozCbtCuBrM0/b2Y=; b=bewr1j6IqCeMWlQ4wKWe5FX3NS3sm0R4nmqHG+TjBQWIdfIXL4XGQfV34QY/TrrgUz RXPnNNN7wJLmQBoF2Hl9+4K3vW/T+BTAdnGr7aKxJ0ACqrFF1RKxTZIloNQbi5UGBQe4 39NStx/+AmheT17yilcE7SiZHFzjrA0JbaycRzExfstslNj/ypgmNYC1meo19M+2wOGP o10CX22FectDI8nCRqj8Erp+mZidFQXqa4D4r75lrqpSuaOZr7Pt7eIgonTY9S2Nx5vh ULq4TZ717TQP+MxYvpRHmVvszBAV1LE6aaMDdFb4LTF/TFl0nQliQqruMIXNshzGLWQq bX0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=XGAUzDlnngJw9tt7CGYwHPVIc1CqozCbtCuBrM0/b2Y=; b=NiWW6PzfZ9zGczUW8nAJr1W42AUIZD6hjek9pQoHT0sGa/H+Quvrq7Gkb+MY6+FtPo +Xcg2cxtBRm+GjKpmbq+3nnjxyZN6fS90BHLGoHM7OoC59ogvanDX/xK3ErUYhnsecEu NqduQ2UcWNHvFiOhgUEIi9odLb+h6VVDilPvkWToguAupGB11SZbseC/lSs6ZechTCuM QQsUa4A/bThICkPWvlhEd8lj//rsaM2ZXCHLLl2SfrvselGOBPiJ7i5UrcFDCMZ7fvH1 +XgIKaz92tGzBAZ7FO/nJDdl6KfP3YxYxUWiajHAiQ8Lt6kAoWQl+sBSN5pQInWjoc+G fvgQ== X-Gm-Message-State: AD7BkJIOi3SBGvAioSOpSHyMlNbmPMD5TImi81z1blE41X3zdtN4cjRQTgkqGvd8CnxpMA== X-Received: by 10.140.195.203 with SMTP id q194mr27757773qha.45.1458350353828; Fri, 18 Mar 2016 18:19:13 -0700 (PDT) Received: from ubuntu.twitter.corp? ([8.25.196.26]) by smtp.gmail.com with ESMTPSA id s188sm7173099qhc.35.2016.03.18.18.19.12 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 18 Mar 2016 18:19:13 -0700 (PDT) X-Mailer: git-send-email 2.4.2.767.g62658d5-twtrsrc Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Each write() has syscall overhead, and writing a large index entails many such calls. A larger write buffer reduces the overhead, leading to increased performance. On my repo, which has an index size of 30m, this saves about 10ms of time writing the index. Signed-off-by: David Turner --- read-cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/read-cache.c b/read-cache.c index d9fb78b..09ebe08 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1714,7 +1714,7 @@ int unmerged_index(const struct index_state *istate) return 0; } -#define WRITE_BUFFER_SIZE 8192 +#define WRITE_BUFFER_SIZE 131072 static unsigned char write_buffer[WRITE_BUFFER_SIZE]; static unsigned long write_buffer_len; -- 2.4.2.767.g62658d5-twtrsrc