From owner-svn-src-head@FreeBSD.ORG Wed Aug 11 17:25:48 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 308F1106566C; Wed, 11 Aug 2010 17:25:48 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-qy0-f182.google.com (mail-qy0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id 8CBF88FC1A; Wed, 11 Aug 2010 17:25:47 +0000 (UTC) Received: by qyk32 with SMTP id 32so462945qyk.13 for ; Wed, 11 Aug 2010 10:25:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=XZOe4xF3ieimRsuHfLcgCJh6RzR/e48szAQmbSUiIO8=; b=YHPZjRq8UhSCvoqbVcfu+TizNmTjwrj0LAUIy/855eMB+ir2JWWA5D4rkup+KdrVhD dbo7pH2CIutD9ommzYidz32Z8NhJ5NQiZKE3yOxjcpa5GzsN3czOsENot27rI0xERyLH Q6N6hnzO5DulRe9GmBtIgLigvthAYLBza/vs0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=U5ttJNc++y4zCwXBa8A3UoJMAviIyuAKN0VzUuPfFOFfuwOYVuvglyT7ynzIAN8q8S k1Zg9hu5E4dS+aOZPlMeFbzT8XUM35BNdvHq/EWxoBkeBZEXwHkwt+8uvBj7Fm0qPXPL GC1CjVkXR5vlhlTdxkJJBO7pNoP7eIzLf4Nno= MIME-Version: 1.0 Received: by 10.229.186.4 with SMTP id cq4mr7778944qcb.0.1281547546120; Wed, 11 Aug 2010 10:25:46 -0700 (PDT) Sender: asmrookie@gmail.com Received: by 10.229.251.6 with HTTP; Wed, 11 Aug 2010 10:25:45 -0700 (PDT) In-Reply-To: <4C62DADF.1000202@FreeBSD.org> References: <201008111051.o7BApRp4028538@svn.freebsd.org> <4C62DADF.1000202@FreeBSD.org> Date: Wed, 11 Aug 2010 19:25:45 +0200 X-Google-Sender-Auth: 3XX7FNKSuk_aV9AprjT4WqSUO8g Message-ID: From: Attilio Rao To: John Baldwin Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r211176 - in head/sys: amd64/amd64 i386/i386 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Aug 2010 17:25:48 -0000 2010/8/11 John Baldwin : > Attilio Rao wrote: >> >> Author: attilio >> Date: Wed Aug 11 10:51:27 2010 >> New Revision: 211176 >> URL: http://svn.freebsd.org/changeset/base/211176 >> >> Log: >> =C2=A0IPI handlers may run generally with interrupts disabled because th= ey >> =C2=A0are served via an interrupt gate. >> =C2=A0 =C2=A0However, that doesn't explicitly prevent preemption and thr= ead >> =C2=A0migration thus scheduler pinning may be necessary in some handlers= . >> =C2=A0Fix that. >> =C2=A0 =C2=A0Tested by: =C2=A0gianni >> =C2=A0MFC after: =C2=A0 =C2=A01 month > > Actually that does prevent preemption if you do not call any code that wo= uld > schedule a thread. =C2=A0I think this change is all safe to revert. Do you recall, then, why lapic_handle_timer() does critical section? It seems to be catered by interrupt gate as well, and I don't see any point re-enabling them explicitly. Thanks, Attilio --=20 Peace can only be achieved by understanding - A. Einstein