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 DF3B9C46467 for ; Wed, 11 Jan 2023 17:39:14 +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=sx/6kCVZPLUxiBAMoe1mA/fhva4aYhHkaO+jDFsDCus=; b=CKsfj2PXMlLXLA T1xWjvpfeSYx41GbEF20RUJH1he1/viGg4yivWPeAeOymXyOZQijuzVhKm3QGuPlq5ylEYWQJeDgY /rPVmDjwTCxDsdwc6CCfWWppcUU4xIhq58Z+4l+qSeB3a5C+WmFl2ldo2p/KSgkEYumbrMpe1B6ts 5KiRmkhohnhKW9ey5fnxRYwgJJZ9asKyapDyceU5E+LxwL0qlKIiX46fdanHbebwd/B3n0+3Zp/Ho CvhYJzMEZ+CsYfsmZJH5ilCuzYkG88SxenQf0hfV9axlkterD7msf35BgYTcx6gLZnDWpI/Hq6tit b5ISh9cafaT7GpSODXHQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFf46-00CSek-8k; Wed, 11 Jan 2023 17:39:06 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFf41-00CScT-NW for linux-riscv@lists.infradead.org; Wed, 11 Jan 2023 17:39:04 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 61793B81BB4; Wed, 11 Jan 2023 17:39:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B39FFC433F0; Wed, 11 Jan 2023 17:38:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673458738; bh=K5LfG8dFO3rNexQDpl+a41K4B9mZRGfxQqhemPNCU04=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=czU7dXOSfcsOqIboHToPyV7iEPq1L8ToFvPId0uE2OjzhX4nK7iEJsfConH+6m6qH pkeMD6eFCM5trAYUOSMyedRVsSLx+obzAwFC1fn1PVni/YKJSWmP8LvPcCFpDwnIk/ ftu06kHqsX+g0mcVIDKNAr9oftb3UZAl+Gd2ro+7WyhugXnsWF461IeAF5B2uclHSx 0uUdG2DMu39AcfRpNiTkjT0nBzaenESljaGhg4x9KHTbDubYoa9Og18P9PBg2hszJV WIC2lVR9zZOg2Mtj/PnHzo3pNPmbBPdJAOSS2ERbTE4H9yNmpWC2Ca2JPiGTMRAttb 9Wu7+lkoOcgNQ== Date: Thu, 12 Jan 2023 01:28:40 +0800 From: Jisheng Zhang To: Palmer Dabbelt Cc: Paul Walmsley , aou@eecs.berkeley.edu, ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, vincenzo.frascino@arm.com, alexandre.ghiti@canonical.com, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Subject: Re: [PATCH v6 RESEND 0/2] use static key to optimize pgtable_l4_enabled Message-ID: References: <20220821140918.3613-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230111_093902_094495_29EE1AE4 X-CRM114-Status: GOOD ( 47.90 ) X-BeenThere: linux-riscv@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-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Sun, Dec 11, 2022 at 06:44:04PM +0800, Jisheng Zhang wrote: > On Sat, Oct 08, 2022 at 10:28:35PM +0800, Jisheng Zhang wrote: > > On Thu, Oct 06, 2022 at 04:37:57PM +0800, Jisheng Zhang wrote: > > > On Wed, Oct 05, 2022 at 06:05:28PM -0700, Palmer Dabbelt wrote: > > > > On Sun, 21 Aug 2022 07:09:16 PDT (-0700), jszhang@kernel.org wrote: > > > > > The pgtable_l4|[l5]_enabled check sits at hot code path, performance > > > > > is impacted a lot. Since pgtable_l4|[l5]_enabled isn't changed after > > > > > boot, so static key can be used to solve the performance issue[1]. > > > > > > > > > > An unified way static key was introduced in [2], but it only targets > > > > > riscv isa extension. We dunno whether SV48 and SV57 will be considered > > > > > as isa extension, so the unified solution isn't used for > > > > > pgtable_l4[l5]_enabled now. > > > > > > > > > > patch1 fixes a NULL pointer deference if static key is used a bit earlier. > > > > > patch2 uses the static key to optimize pgtable_l4|[l5]_enabled. > > > > > > > > > > [1] http://lists.infradead.org/pipermail/linux-riscv/2021-December/011164.html > > > > > [2] https://lore.kernel.org/linux-riscv/20220517184453.3558-1-jszhang@kernel.org/T/#t > > > > > > > > > > Since v5: > > > > > - Use DECLARE_STATIC_KEY_FALSE > > > > > > > > > > Since v4: > > > > > - rebased on v5.19-rcN > > > > > - collect Reviewed-by tags > > > > > - Fix kernel panic issue if SPARSEMEM is enabled by moving the > > > > > riscv_finalise_pgtable_lx() after sparse_init() > > > > > > > > > > Since v3: > > > > > - fix W=1 call to undeclared function 'static_branch_likely' error > > > > > > > > > > Since v2: > > > > > - move the W=1 warning fix to a separate patch > > > > > - move the unified way to use static key to a new patch series. > > > > > > > > > > Since v1: > > > > > - Add a W=1 warning fix > > > > > - Fix W=1 error > > > > > - Based on v5.18-rcN, since SV57 support is added, so convert > > > > > pgtable_l5_enabled as well. > > > > > > > > > > > > > > > Jisheng Zhang (2): > > > > > riscv: move sbi_init() earlier before jump_label_init() > > > > > riscv: turn pgtable_l4|[l5]_enabled to static key for RV64 > > > > > > > > > > arch/riscv/include/asm/pgalloc.h | 16 ++++---- > > > > > arch/riscv/include/asm/pgtable-32.h | 3 ++ > > > > > arch/riscv/include/asm/pgtable-64.h | 60 ++++++++++++++++++--------- > > > > > arch/riscv/include/asm/pgtable.h | 5 +-- > > > > > arch/riscv/kernel/cpu.c | 4 +- > > > > > arch/riscv/kernel/setup.c | 2 +- > > > > > arch/riscv/mm/init.c | 64 ++++++++++++++++++----------- > > > > > arch/riscv/mm/kasan_init.c | 16 ++++---- > > > > > 8 files changed, 104 insertions(+), 66 deletions(-) > > > > > > > > Sorry for being slow here, but it looks like this still causes some early > > > > boot hangs. Specifically kasan+sparsemem is failing. As you can probably > > > > see from the latency I'm still a bit buried right now so I'm not sure when > > > > I'll have a chance to take more of a look. > > > > > > Hi Palmer, > > > > > > Before V4, there is a bug which can cause kernel panic when SPARSEMEM > > > is enabled, V4 have fixed it by moving the riscv_finalise_pgtable_lx() > > > after sparse_init(). And I just tested the riscv-pgtable_static_key > > > branch in your tree, enabling KASAN and SPARSEMEM, system booted fine. > > > I'm not sure what happened. Could you please send me your kernel > > > config file? I want to fix any issue which can block this series being > > > merged in 6.1-rc1. > > > > Hi Palmer, > > > > I know you are busy ;) Do you have time to send me your test kernel > > config file so that I can reproduce the "early boot hang"? > > > > Thanks > > Hi Palmer, > > I think the early boot hangs maybe the same as the one which has been > fixed by commit 9f2ac64d6ca6 ("riscv: mm: add missing memcpy in > kasan_init"). Will you give this series another try for v6.2-rc1? If > the boot hang can still be reproduced, could you please send me your > .config file? > > Thanks in advance Hi all, Just request to comment what to do with this patch, I think there are two independent points to consult: 1. IIRC, Palmer gave this patch two chances to merge in early versions but he found boot hangs if enable KASAN and SPARSEMEM, while I can't reproduce the boot hang. And I also expect the hang should be fixed by commit 9f2ac64d6ca6 ("riscv: mm: add missing memcpy in kasan_init") 2. Now we know alternative is preferred than static branch for ISA extensions dynamic code patching. So we also need to switch static branch usage here to alternative mechanism, but the problem is SV48 and SV57 are not ISA extensions, so we can't directly make use of the recently introduced riscv_has_extension_likely|unlikely()[1] which is based on alternative mechanism. Any comments are appreciated. Thanks in advance [1] https://lore.kernel.org/linux-riscv/20230111171027.2392-1-jszhang@kernel.org/T/#t _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv