From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id C390C1F9FD for ; Thu, 25 Feb 2021 07:19:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229596AbhBYHSH (ORCPT ); Thu, 25 Feb 2021 02:18:07 -0500 Received: from pb-smtp2.pobox.com ([64.147.108.71]:62377 "EHLO pb-smtp2.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232290AbhBYHRb (ORCPT ); Thu, 25 Feb 2021 02:17:31 -0500 Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 8AEB49A911; Thu, 25 Feb 2021 02:16:43 -0500 (EST) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=sdEH+yECPkqxEOs4/mVbIwD3CYM=; b=gFNIra tokqehkIJYBlpFsAEJ7Z6URAe5OtE7WZFngogNiIERTmV2dQ3x7HDcE3AfaHqaym q//OyOP6GISqXLT3DRjClefWEbr4jyxPbuoe9y/lCCJNrcmWGqnKqoXJCDR8Vw1v P3iz4DkskJ4Y6MY8VlhiYV9WtsSQ/yDIsck2Q= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=AAj4yVYDh3yi9QkUUrcEzByzaaPSLXIV HPJsjEH1glbslpHdAEUQL3Gz5bWbr0R0T3Ge//QfbcHtWhsSEGhpBzNMDHpqtqCW M2Cfb81+efY4KzvxAnUofXbusMBJ+FNp9zROUBoXXup6AobMjgzpaPE9HtUW/3Kw vWnmyGQ4cgg= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 829689A910; Thu, 25 Feb 2021 02:16:43 -0500 (EST) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.74.119.39]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 1302A9A90F; Thu, 25 Feb 2021 02:16:43 -0500 (EST) (envelope-from junio@pobox.com) From: Junio C Hamano To: Chris Torek Cc: Neeraj Singh , Jeff Hostetler , Git List , "Neeraj K. Singh" Subject: Re: [PATCH] read-cache: make the index write buffer size 128K References: Date: Wed, 24 Feb 2021 23:16:42 -0800 In-Reply-To: (Chris Torek's message of "Wed, 24 Feb 2021 22:58:36 -0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1.90 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Pobox-Relay-ID: 6973378A-7739-11EB-945B-74DE23BA3BAF-77302942!pb-smtp2.pobox.com Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Chris Torek writes: > Linux/BSD/etc `stat` system calls report st_blksize values to tell > user code the optimal size for read and write calls. Does Windows > have one? (It's not POSIX but is XSI.) > > (How *well* the OS reports `st_blksize` is another question > entirely, but at least if the report says, say, 128k, and that's > wrong, that's no longer Git's fault. :-) ) > ... > 128K is correct for ZFS; 64K is typically correct for UFS2; 8K is > the old UFS1 size. Anything under that has been too small for > a long time. :-) That's rather tempting. After opening a locked index to write things out, the value is a single fstat() away...