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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBA3FC433F5 for ; Wed, 3 Nov 2021 17:26:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B09AF61073 for ; Wed, 3 Nov 2021 17:26:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbhKCR30 (ORCPT ); Wed, 3 Nov 2021 13:29:26 -0400 Received: from outbound5b.eu.mailhop.org ([3.125.66.160]:12424 "EHLO outbound5b.eu.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229654AbhKCR30 (ORCPT ); Wed, 3 Nov 2021 13:29:26 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1635959447; cv=none; d=outbound.mailhop.org; s=arc-outbound20181012; b=sDm/tmZWxB1/WXR6MKs5nJ0gAZ/G09eJkQ9lQU22WtWrrmU8aJKf8sdAP2vWQAONyGIV3F+2Nsiqh /+AvEZusV5TUuukynsTWpXI5YS+Z5BMPf0SfrRa1WfKSymgAS8Agfm92GT+BzAqaLt8tjajSEZF7EJ 1tb0BGSOsj4wEnBNb9j5OAIDciqqqwXBfj9yr6kb9Wgu+ZjRVsPC/CvXO5pilH69TE9bV93vpR/1CV WXbLyIAepZXuUnaquUxvdT4pZlC52gexDrrV4iRyzDLguTv4cRwNTF3pyPhv8OL6A2MIUGNgjZwVYl RJZBUnp5pwq1JOiAQ3rrfTl3o8uBIBQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=arc-outbound20181012; h=content-type:mime-version:message-id:in-reply-to:date:references:subject:cc: to:from:dkim-signature:dkim-signature:from; bh=X4bM2Gi6Ibr1ECS7ugQvTRk/gYDaf3DuOOWj2Z9jitk=; b=HweqYYUW/TIHmPc9qjYF/2ro0y8fEAnckw9XmP8bTs1knBAgiGEucvJdMKf6VTQvrblzPmwglLXaI r2R1bUibnW1hnBBDr1XIqtSTHxIHoXyEZmu29HEmYRo6UpCkc4rz/tgFfyJQjXNvPZPvzhjMeUWA24 PE7sOuTvScOFj+syUoiFV7DCIi7fgC80Ol0BYXIa+C3Dx3bHRO4ZDXiCPM5fvlQfVyIhpu6WKDJuio 5xf/z5mCQOqLtcmqQwjDUb9i+FcT5CPKlmaVoNzEYdqujGII++bUw8BCiSnvuw/YHfx3XSVDE4wFi3 5sH0LnN9SMNn8uEtP0my3DgmjlJhO6Q== ARC-Authentication-Results: i=1; outbound3.eu.mailhop.org; spf=pass smtp.mailfrom=stackframe.org smtp.remote-ip=91.207.61.48; dmarc=none header.from=stackframe.org; arc=none header.oldest-pass=0; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=stackframe.org; s=duo-1634547266507-560c42ae; h=content-type:mime-version:message-id:in-reply-to:date:references:subject:cc: to:from:from; bh=X4bM2Gi6Ibr1ECS7ugQvTRk/gYDaf3DuOOWj2Z9jitk=; b=CqQVQwzbTNwVokVANQzu/n1Buqx9vxHGllid5++sq6p7+ou3RefiQrVOa5ZiKZTJpXVGxIBKNM4Pe yKVarbwj7s7/pXhfNZXlCwmblHxkiGqD1TwPygetbfCpPQbKXzPK6llfdOU7oYX7oh/zyBq80uw8fk 3WNIYQm0qGWpRZ4c= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=dkim-high; h=content-type:mime-version:message-id:in-reply-to:date:references:subject:cc: to:from:from; bh=X4bM2Gi6Ibr1ECS7ugQvTRk/gYDaf3DuOOWj2Z9jitk=; b=DE8u4lrsPhpO/ieqXWmhP7Qv8+WQLQ+kwrqK+CVW3ebJGTWowmXNZxPaSIkjk2hrzIE01q1V2sPLb VPCj/9PHoJEV2qB1aspng90dOtqbZDEddlOXRardXo8Ipx/CIWJ2ju6F/OPj2vddde5idGGvexxuKb mNxNRM8qPX78K1UD6mRQUESm3WqXSaw1qVL1SPATt3QBiiOit/1LHvve5Z0cTolxFXvX+UwoJl8Vjz 5oOZrpWbMnmhyGpiLNne2sUNVBKXbzBSyGnYit8T4uj/T3rwn/87JHyIfITbwFbKmKke6t+CKDuRYE CSXAx3kG3HUvJd61zuR3aQyXa3/bVqQ== X-Originating-IP: 91.207.61.48 X-MHO-RoutePath: dG9ta2lzdG5lcm51 X-MHO-User: fa484073-3cc8-11ec-8655-95b64d6800c5 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Mail-Handler: DuoCircle Outbound SMTP Received: from mail.duncanthrax.net (propper.duncanthrax.net [91.207.61.48]) by outbound3.eu.mailhop.org (Halon) with ESMTPSA id fa484073-3cc8-11ec-8655-95b64d6800c5; Wed, 03 Nov 2021 17:10:43 +0000 (UTC) Received: from hsi-kbw-109-193-149-228.hsi7.kabel-badenwuerttemberg.de ([109.193.149.228] helo=x1.stackframe.org.stackframe.org) by mail.duncanthrax.net with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1miJmc-00DYPf-I0; Wed, 03 Nov 2021 19:10:42 +0200 From: Sven Schnelle To: Helge Deller Cc: John David Anglin , linux-parisc Subject: Re: [PATCH v2] parisc: Don't disable interrupts in cmpxchg and futex operations References: <20211015195612.25203-1-svens@stackframe.org> <969e8f20-d27c-77cd-62c1-ddb86213ddec@gmx.de> <8bef26c2-daee-2a6c-1828-100a5b27e205@gmx.de> <28325394-99de-67f4-dcca-b1caf1105df2@bell.net> <87o87oxhhf.fsf@x1.stackframe.org> <48780780-0f8c-5aa9-d362-a9b9ddeaeedb@gmx.de> <877de734aj.fsf@x1.stackframe.org> Date: Wed, 03 Nov 2021 18:10:41 +0100 In-Reply-To: (Helge Deller's message of "Wed, 3 Nov 2021 15:42:45 +0100") Message-ID: <87k0hpjhbi.fsf@x1.stackframe.org> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org Helge Deller writes: > * Sven Schnelle : >> John David Anglin writes: >> >> > On 2021-10-17 12:30 p.m., Helge Deller wrote: >> >> It seems the warnings are gone if I remove the irq masking. >> >> I see the options: >> >> a) revert the irq masking in syscall.S. Not sure if it really hurts performance. >> >> b) revert the patch from Sven. >> >> c) insert code to turn back irq on in the fault handler if we are on the gateway page. >> >> What is your thought? >> > >> > After some thought, I believe option a) is the best. I no longer think interrupts can be >> > disabled in the futex and cmpxchg operations because of COW breaks. This not ideal but >> > I suspect it's the best we can do. >> > >> > For the cmpxchg operations in syscall.S, we rely on the code to not schedule off the gateway >> > page. For the futex, I added code to disable preemption. >> > >> > So far, I haven't seen the warnings with the attached change but the change is only lightly tested. >> >> Thanks Dave. I just applied it to my tree and will give it a spin. > > Sven, did you had some outcome? The outcome is that i haven't seen any problems yet. > I've cleaned up Daves patch and applied it to my for-next tree: > https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=for-next&id=b7cd8a368c986abf184e609772b083f43e5d522d > together with this patch from Sven ("parisc: don't enable irqs > unconditionally in handle_interruption()"): > https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=for-next&id=493f84fcb3a791350ffaa2fa2984a0815a924e39 > > When not applying to master branch from Linus, this patch is needed as well: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1030d681319b43869e0d5b568b9d0226652d1a6f > > All is in my for-next tree. > Testing seems that those are OK and I don't see any > "BUG: using __this_cpu_add() in preemptible [00000000] code" warnings > any more. > > Any objections if I push those patches to Linus soon? No objections. Sven