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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A9383C433FE for ; Thu, 20 Oct 2022 16:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=v5U409TiIQ8aDzT5ZISizMS+A78Sqy4ca1anzK0osps=; b=hutF6eFrGTeA7w FlGCa7JFvVGHi724rnAet6fEREzxcQ1IgOQkZowwOTaXsxjpw91ENYK5c4zmLFHDrlucwbDTBALvA CwS1s9d6ljUQJeMgRuiVUdtIr3TN+fMx7vgtArQxlru0Q8yhuuEk6JHQ82I+YXQra2Uz6tvLzrg1O WXtX/7ykcZCjdqQ+vaBsk54CRtQsgfBs9Tm5cTz1Q99fG6vSkj1T2k4s9nZlitvQZ29nFh6I552WE xDR9w+9tt7mncmvTSDR3ImEQBvlExeOrLySzXkMU4JBwY3j4PF+At+DtWIXnEFzeVNR/4018o7FY0 ZlYzIto4ImqQGErmY2jQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olYlm-000aiM-Jf; Thu, 20 Oct 2022 16:51:46 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1olYlj-000afQ-Iw for linux-arm-kernel@lists.infradead.org; Thu, 20 Oct 2022 16:51:45 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=bsrmTa68MJY8KkG/NoF58D+w4Y5gc7WtNmjgNur4ts8=; b=fID3YRw//dhl3IO6+CGYGK8pFL a+Pccbx7i0P3pKtPm0t7jt1V28IiQfLQrsvspkNu7hJ1lZ82AH5Z4DgeMcBQ3NHQ70iJv2rX/Yora SYj3xI05RQE0ipCDS8MHOT4cH8WhkGr7z1SYjYbjDM1m7bZPyeGddzzpQPfmzYQhaGexa8CLGaFg6 yeibixhwe1a8GTeA7/Hm83Kv7fB1eqeESpfvzeIuMhw7Cf+3b1duu6QVCVdWSmkxbWgdz+G4ilYy3 vbBAiv5KDfd/BmSIH0UT3i0ZX8QnqIW3kALPlo7O70ZRnp/MJE+UVM2lEcTTM5XQ/uM4E9eiybKzq lukzx0JA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:34834) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1olYld-0007YR-9x; Thu, 20 Oct 2022 17:51:37 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1olYla-0003Jk-It; Thu, 20 Oct 2022 17:51:34 +0100 Date: Thu, 20 Oct 2022 17:51:34 +0100 From: "Russell King (Oracle)" To: Yury Norov Cc: Catalin Marinas , Mark Rutland , Will Deacon , linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , Alexey Klimov , Andy Shevchenko , Andy Whitcroft , Dennis Zhou , Geert Uytterhoeven , Guenter Roeck , Kees Cook , Linus Torvalds , Rasmus Villemoes Subject: Re: [RFC PATCH 0/2] Switch ARM to generic find_bit() API Message-ID: References: <20221020032024.1804535-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221020032024.1804535-1-yury.norov@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221020_095143_644903_2FB5AE45 X-CRM114-Status: GOOD ( 26.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Oct 19, 2022 at 08:20:22PM -0700, Yury Norov wrote: > Hi Russell, all, > > I'd like to respin a patch that switches ARM to generic find_bit() > functions. > > Generic code works on par with arch or better, according to my > testing [1], and with recent improvements merged in v6.1, it should > be even faster. > > ARM already uses many generic find_bit() functions - those that it > doesn't implement. So we are talking about migrating a subset of the > API; most of find_bit() family has only generic implementation on ARM. > > The only concern about this migration is that ARM code supports > byte-aligned bitmap addresses, while generic code is optimized for > word-aligned bitmaps. > > In my practice, I've never seen unaligned bitmaps. But to check that on > ARM, I added a run-time check for bitmap alignment. I gave it run on > several architectures and found nothing. > > Can you please check that on your hardware and compare performance of > generic vs arch code for you? If everything is OK, I suggest switching > ARM to generic find_bit() completely. > > Thanks, > Yury > > [1] https://lore.kernel.org/all/YuWk3titnOiQACzC@yury-laptop/ I _really_ don't want to play around with this stuff right now... 6.0 appears to have a regression on arm32 early on during boot: [ 1.410115] EXT4-fs error (device sda1): htree_dirblock_to_tree:1093: inode #256: block 8797: comm systemd: bad entry in directory: rec_len % 4 != 0 - offset=0, inode=33188, rec_len=35097, size=4096 fake=0 Booting 5.19 with the same filesystem works without issue and without even a fsck, but booting 6.0 always results in some problem that prevents it booting. Debugging this is not easy, because there also seems to be something up with the bloody serial console - sometimes I get nothing, other times I get nothing more than: [ 2.929502] EXT4-fs error (de and then the output stops. Is the console no longer synchronous? If it isn't, that's a huge mistake which can be seen right here with the partial message output... so I also need to work out how to make the console output synchronous again. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel