From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22B52C433B4 for ; Sun, 2 May 2021 18:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02BA461358 for ; Sun, 2 May 2021 18:00:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232411AbhEBSBF (ORCPT ); Sun, 2 May 2021 14:01:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231788AbhEBSBE (ORCPT ); Sun, 2 May 2021 14:01:04 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E42DC06174A; Sun, 2 May 2021 11:00:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ox1uG4hXSi3kmGSi8Ujj0SwwhYl/DRs1whuuY2NKW14=; b=g35IcNWK1Oxa2pWmr5AxOKI/Rk x8KN9LobeqzwQ0UigvVOIqQZarRaoU0r47ge155inBaMH/tMLYO8mJANvOCx9niPTT3OT7g7XmlLI 3+ZdRnKtF8WpIdSkRECOyWp8oFqBPrLuiN9bvY1zuqgi4pYdnCA0oDCghaAFE+osKV4VHF19Vc4JE VTHa5Fe8z8JWgqhHOGKHuF2dGmL+dzUHChf8WyTEGcgFludBznxL74jKs73YBI9fMeERnh7IwIF1U MkafHODJ2BTt+B45VENmH44FrWOpOpTsfV8nvGEF4cQP1qPo1wKidZh/1MhHCcDbyInnLwwTAZXbr iZyQ0PnA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1ldGNe-00E6DJ-TB; Sun, 02 May 2021 17:59:52 +0000 Date: Sun, 2 May 2021 18:59:46 +0100 From: Matthew Wilcox To: Linus Torvalds Cc: Al Viro , Linux Kernel Mailing List , linux-fsdevel Subject: Re: [git pull] work.misc Message-ID: <20210502175946.GY1847222@casper.infradead.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, May 02, 2021 at 09:26:26AM -0700, Linus Torvalds wrote: > On Sat, May 1, 2021 at 6:30 PM Al Viro wrote: > > > > Mikulas Patocka (1): > > buffer: a small optimization in grow_buffers > > Side note: if that optimization actually matters (which I doubt), we > could just make getblk and friends take s_blocksize_bits instead of > the block size. And avoid the whole "find first bit" thing. > > As it is, we end up doing odd and broken things if anybody were to > ever use a non-power-of-2 blocksize (we check that it's a multiple of > the hw blocksize, we check that it's between 512 and PAGE_SIZE, but we > don't seem to check that it's a power-of-2). I think we have checks that the hw blocksize is a power-of-two (maybe just in SCSI? see sd_read_capacity()) I don't see much demand in the storage industry for non-power-of-two sizes; I was once asked about a 12kB sector size at Intel, but when I said "no", they didn't seem surprised. I see interest in going smaller (cacheline sized) for pmem and I see interest in going larger (16kB sector sizes) for NAND.