From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Starikovskiy Subject: Re: [PATCH] ACPICA: don't cond_resched() when irq_disabled or in_atomic Date: Thu, 10 Dec 2009 20:58:45 +0300 Message-ID: <4B2136D5.1030402@gmail.com> References: <1259900760-6424-1-git-send-email-dfeng@redhat.com> <20091210100907.GA2446@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from fg-out-1718.google.com ([72.14.220.156]:53007 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761059AbZLJR6l (ORCPT ); Thu, 10 Dec 2009 12:58:41 -0500 In-Reply-To: <20091210100907.GA2446@ucw.cz> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Pavel Machek Cc: Xiaotian Feng , lenb@kernel.org, ming.m.lin@intel.com, robert.moore@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Hi Pavel, Please elaborate... Your comments "ugly as hell" are too often to be specific... There is only one use of ACPI_PREEMPTION_POINT(), and it is in the ACPICA code, which we all agreed to keep OS independent, thus the need for #define. Do you see any other way to add preemption point without introducing Linux-specific code into ACPICA? Thanks, Alex. Pavel Machek =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > On Fri 2009-12-04 12:26:00, Xiaotian Feng wrote: > =20 >> commit 8bd108d adds preemption point after each opcode parse, then >> a sleeping function called from invalid context bug was founded >> during suspend/resume stage. this was fixed in commit abe1dfa by >> don't cond_resched when irq_disabled. But recent commit 138d156 chan= ges >> the behaviour to don't cond_resched when in_atomic. This makes the >> sleeping function called from invalid context bug happen again, whic= h >> is reported in http://lkml.org/lkml/2009/12/1/371. >> >> The fix is to cond_sched() only when preemptible, which means not in >> irq_disabled or in_atomic. >> >> @@ -152,7 +152,7 @@ static inline void *acpi_os_acquire_object(acpi_= cache_t * cache) >> #include >> #define ACPI_PREEMPTION_POINT() \ >> do { \ >> - if (!in_atomic_preempt_off()) \ >> + if (preemptible()) \ >> cond_resched(); \ >> } while (0) >> =20 > > Note that this is ugly as hell. It means we have two acpi > interpretters in kernel, one for preemptible, one for non-preemptible= , > with very different behaviour. > > It would be slightly nicer to pass the "preemptible" info explicitely= , > as function parameters. > > It would be even better not to need that difference. > > Pavel > =20 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html