From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH 4/5] ib/core: add support for extended performance counters in sysfs Date: Tue, 1 Nov 2011 16:11:35 -0600 Message-ID: <20111101221135.GP26974@obsidianresearch.com> References: <20111101162218.GA10710@obsidianresearch.com> <20111101173625.GH26974@obsidianresearch.com> <20111101183730.GI26974@obsidianresearch.com> <20111101215200.GN26974@obsidianresearch.com> <20111101150358.17d232ee.weiny2@llnl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20111101150358.17d232ee.weiny2-i2BcT+NCU+M@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ira Weiny Cc: Roland Dreier , Or Gerlitz , Or Gerlitz , linux-rdma List-Id: linux-rdma@vger.kernel.org On Tue, Nov 01, 2011 at 03:03:58PM -0700, Ira Weiny wrote: > > And again, this is a useless interface in IB. > > Why do you mean by this? A counter that is randomly reset by an external IB performance manager is not useful for collecting local statistical information. A counter that saturates and cannot be reset locally is not useful for any automatic process. Why have a sysfs counter at all when you can just ask the PMA and get exactly the same data? I can't make a SNMP MIB from this counter. I can't make graphs from this counter. I can't do anything with it except show it to the user and hope they understand when it was last reset, or understand what to do when it is saturated. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html