From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Date: Wed, 28 Jan 2004 20:19:59 +0000 Subject: Re: [RFC/PATCH, 2/4] readX_check() performance evaluation II Message-Id: <20040128211959.0d367c30.ak@suse.de> List-Id: References: <00a301c3e541$c13a6350$2987110a@lsd.css.fujitsu.com> <20040128182003.GL11844@parcelfarce.linux.theplanet.co.uk> <20040128204049.627e6312.ak@suse.de> <20040128211554.0cc890fb.ak@suse.de> In-Reply-To: <20040128211554.0cc890fb.ak@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andi Kleen Cc: torvalds@osdl.org, willy@debian.org, ishii.hironobu@jp.fujitsu.com, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org On Wed, 28 Jan 2004 21:15:54 +0100 Andi Kleen wrote: > > > > > Just set a flag aka "may need checking", and let the check be done by the > > actual "read_pcix_error()" code. > > Where would you put the flag? > > Doing it global may give false errors for the wrong device with async MCEs > and on SMP. > > For putting it into the pci_dev you need to take logs to walk the list. > If you delay it to a softirq for safely getting the lock it would be set too late. > > Putting it into a different table indexed by pci index would be also racy > with hotplug. ... to follow up myself ... I suppose moving the pci_dev lists to RCU could make the flag in pci-dev work. But it would be still a bit tricky with preemptive kernels. -Andi