From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org ([198.145.29.96]:51528 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbeEQVZy (ORCPT ); Thu, 17 May 2018 17:25:54 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Date: Thu, 17 May 2018 17:25:52 -0400 From: okaya@codeaurora.org To: Rajat Jain Cc: linux-pci , Bjorn Helgaas , linux-pci-owner@vger.kernel.org Subject: Re: RFC: Counters for PCI Express AERs In-Reply-To: References: Message-ID: Sender: linux-pci-owner@vger.kernel.org List-ID: On 2018-05-17 17:05, Rajat Jain wrote: > Hello, > > I have been thinking about adding counters for different kinds of AERs > and expose them via sysfs. IMHO this would help by giving some sense > of "link quality" for PCIe links (a lot of correctable AERs may > indicate system is workable, but may indicate some signal integrity > issues etc). Currently, on a correctable AER, we do log them, but > having them in sysfs would allow userspace tools to possibly > (periodically) poll them and raise an appropriate warning in case of > too many errors. I know that for my purposes, getting some idea of PCI > link quality or a way to quantize it, would help. > > Do you think such counters make sense or would be helpful generically? > Also, please let me know if something like this already exists? This question came from FB folks last year. They were told to use the perf events for counting. I don't honestly have a strong opinion. > > Thanks, > > Rajat