From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: [ofa-general] Re: [GIT PULL] please pull ummunotify Date: Wed, 30 Sep 2009 10:06:32 -0700 Message-ID: References: <1253187028.8439.2.camel@twins> <1253198976.14935.27.camel@laptop> <20090929171332.GD14405@elf.ucw.cz> <20090930094456.GD24621@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20090930094456.GD24621-X9Un+BFzKDI@public.gmane.org> (Ingo Molnar's message of "Wed, 30 Sep 2009 11:44:56 +0200") Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ingo Molnar Cc: Pavel Machek , Peter Zijlstra , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Paul Mackerras , Anton Blanchard , general-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org List-Id: linux-rdma@vger.kernel.org > Performance events filtering is being worked on and now with the proper > non-DoS limit you've added you can lose events too, dont you? So it's > all a question of how much buffering to add - and with perf events too > you can buffer arbitrary large amount of events. No, the idea for non-DoS for ummunotify is that we would limit the number of regions the application can register; so an application might hit the limit up front but no runtime loss of events once a region was registered successfully. > I think this could be done in a simpler, less limited, more generic, > more useful form by using some variation of perf events. > > You should be able to get all that you want by adding two TRACE_EVENT() > tracepoints and using the existing perf event syscall to get the events > to user-space. Yes, I would like to use perf events too. Would it be plausible to create a way for userspace to create a "counter" for each address range being watched? Then events would not be lost, because those counters would become non-zero. > Meaning that this: > 9 files changed, 1060 insertions(+), 1 deletions(-) Note that lots/ of the files touched here are in Documentation or are one-line changes to Makefiles etc. - R. -- 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