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 B69C0C433EF for ; Wed, 20 Oct 2021 19:05:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 935E6611B0 for ; Wed, 20 Oct 2021 19:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231328AbhJTTIC (ORCPT ); Wed, 20 Oct 2021 15:08:02 -0400 Received: from outbound5e.eu.mailhop.org ([52.28.168.19]:32143 "EHLO outbound5e.eu.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231278AbhJTTIB (ORCPT ); Wed, 20 Oct 2021 15:08:01 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1634756746; cv=none; d=outbound.mailhop.org; s=arc-outbound20181012; b=NCmLkjEXyIVkDhMTRORhqtwLEziI+ydU5OZRPzhigeXUZsXdKB5ma/nJbJWz8lznSiXkUdKaqD8Vg RHuxdawHjkeVL7ocCIptVPdxbNsfYjlPAARQD9/r58Ei1/IGpyhmTIJOd0vtU+cqGuvtsOO13lmiZP QJqT9fRO3YbmMmhtn8kwTUs7NGNq0V0kIJHup8Y4lfysWWjlFIZoZB2pwU0j7cebyH0I7nAznH7Id0 hajP8YUPcdxbz0+dDLbS10eozqFeEV2XISIEzBpKEm9JnWLztOAWH2yrn54w3M501KseAJ7yPsoTYJ hi5SBI5qk8U4LbJ4tihSUCGA+sPmr7A== 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=Wp7CG+/sIewEKUFnN0zyXL+VywmG8BsRhClow92VS6Y=; b=V40xGHGPWUCtJsG1KUKokwcw2PLCgWJR7patjs599E62H04OmFQ5gOYgZf85hz3Aq4V/UV4TetTyN ++5bC0iMpxjN4x5qqkfS0NuG4TWAbuk8rjuYwfnKgw1VIebvs4TNm2zhIG//F1qONQ8bpGx1+j+2kX Pk09yXhYokCeDEPNVCwfvinWnP2Ou9dtKLgs71f7UiWQtrkZ40LhCXGfEMlIklg6tIHc8AOuV8QvaK KFfym1wAoMLYiMrX9+ksrisClwYMNXMOwxKqD+XTXz5eUskU/NokIxrpjFnZspFnJbmIyeDjpFm9K2 gQByCJfNyqkNrjhDMohz8YlwGlW3fdw== ARC-Authentication-Results: i=1; outbound2.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=Wp7CG+/sIewEKUFnN0zyXL+VywmG8BsRhClow92VS6Y=; b=VCQvjv9q0I676V7TZ7SH04XiTyQQ0eoYgqb+AtrztCpoyquK6M3h+ecidvsS5EP4YZMf6XDytjOak Syv39dL2nvBntRcZBzUIaiLnZUK/WOIvqQvIg6C5+Akvar27W4GWpFnsXoDDcBSBvGDs5X+nYWdHiU BIL+stkz2h8EST7o= 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=Wp7CG+/sIewEKUFnN0zyXL+VywmG8BsRhClow92VS6Y=; b=TO7/hvJSeSEQpoI0Xm+81IAoFO3DXnxzrNLi5p++0DsLSPXIKv5HUZx/JAKeZGyhINjOQt2McjFFE vk6BMoF0ahdpb4WFbZNLXHK/eLA7xzuElBlb4JoiGNZJNZI0VRM0vn54iY2Z9SKcTBoMYwj2rn/5bc LpEoFrcCtCSxiEIUk+w+wehsY6kF1b5A8xu5DamQEMonucF8OIrR6C3T1IjVLK9oeC15sMOS74OVrI jJggUn5MGv8T7TRdBrNIg8Iwf2AVxmQXNUjG1njmG1OrlDnq7umZt+oywFxv73jkrO30j64xaQgsPu K2F5weEx6AcZlHujCvJ9ZIuR6MG57Fg== X-Originating-IP: 91.207.61.48 X-MHO-RoutePath: dG9ta2lzdG5lcm51 X-MHO-User: b91aee1d-31d8-11ec-a070-973b52397bcb 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 outbound2.eu.mailhop.org (Halon) with ESMTPSA id b91aee1d-31d8-11ec-a070-973b52397bcb; Wed, 20 Oct 2021 19:05:43 +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 1mdGuE-00BpXn-Df; Wed, 20 Oct 2021 22:05:42 +0300 From: Sven Schnelle To: John David Anglin Cc: Helge Deller , linux-parisc Subject: Re: [PATCH] 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> Date: Wed, 20 Oct 2021 21:05:40 +0200 In-Reply-To: (John David Anglin's message of "Wed, 20 Oct 2021 14:32:55 -0400") Message-ID: <877de734aj.fsf@x1.stackframe.org> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org 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.