lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAM9d7cgM9rMjfd5q3VNUtBeJ9q7=k1+GWhq7tmnwrZR=gqFvtA@mail.gmail.com> Date: Wed, 7 Oct 2015 18:06:12 +0900 From: Namhyung Kim <namhyung@...nel.org> To: Adrian Hunter <adrian.hunter@...el.com> Cc: Arnaldo Carvalho de Melo <acme@...nel.org>, Ingo Molnar <mingo@...nel.org>, Peter Zijlstra <a.p.zijlstra@...llo.nl>, Jiri Olsa <jolsa@...hat.com>, LKML <linux-kernel@...r.kernel.org>, Frederic Weisbecker <fweisbec@...il.com>, Stephane Eranian <eranian@...gle.com>, David Ahern <dsahern@...il.com>, Andi Kleen <andi@...stfloor.org> Subject: Re: [RFC/PATCH 03/38] perf tools: Move auxtrace_mmap field to struct perf_evlist Hi Adrian, On Tue, Oct 6, 2015 at 6:26 PM, Adrian Hunter <adrian.hunter@...el.com> wrote: > On 06/10/15 12:03, Namhyung Kim wrote: >> Hi Adrian, >> >> On Mon, Oct 5, 2015 at 8:29 PM, Adrian Hunter <adrian.hunter@...el.com> wrote: >>> On 02/10/15 21:45, Arnaldo Carvalho de Melo wrote: >>>> Em Fri, Oct 02, 2015 at 02:18:44PM +0900, Namhyung Kim escreveu: >>>>> Since it's gonna share struct mmap with dummy tracking evsel to track >>>>> meta events only, let's move auxtrace out of struct perf_mmap. >>>> Is this moving around _strictly_ needed? >>> >>> Also, what if you wanted to capture AUX data and tracking together. >> >> Hmm.. I don't know what's the problem. It should be orthogonal and >> support doing that together IMHO. Maybe I'm missing something about >> the aux data processing and Intel PT. I'll take a look at it.. >> > > It is only orthogonal if you assume we will never want to support parallel > processing with Intel PT. We'll definitely want it. :) > > The only change that needs to be made is not to assume there is only 1 > tracking event. IIUC Intel PT (and BTS?) needs maximum 2 dummy events - one is to track task/mmap and another is to track context switches. The latter is basically a light-weight version of the sched_switch event, right? For parallel processing, each cpu needs to keep current thread to synthesize events from auxtrace data. So if it processed the switch events before processing samples, it'd need to build long lists of current thread per cpu. IMHO it'd be better to process the switch events with samples using multi-thread rather than processing them prior to samples. So how about this? It'd use *always* 2 dummy (or 1 dummy + 1 sched_switch) events. The tracking dummy events would be recorded on the tracking mmaps and switch (dummy) event would be recorded on the main mmaps. This way we can parallelize the auxtrace processing without the list of current thread IMHO. Do I miss something? > > IMHO there could be separate mmap_params also, which would allow for > different mmap sizes for the tracking and main mmaps. Currently, the tracking mmap size is fixed at an arbitrary size (128KiB) regardless of the main mmaps. I can add an option to change the tracking mmap size too. Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists