linux-kernel - Re: [PATCH v8 0/3]: perf: reduce data loss when profiling highly parallel CPU bound workloads

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180910100303.GA101776@gmail.com>
Date:   Mon, 10 Sep 2018 12:03:03 +0200
From:   Ingo Molnar <mingo@...nel.org>
To:     Jiri Olsa <jolsa@...hat.com>
Cc:     Alexey Budankov <alexey.budankov@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v8 0/3]: perf: reduce data loss when profiling highly
 parallel CPU bound workloads


* Jiri Olsa <jolsa@...hat.com> wrote:

> > Per-CPU threading the record session would have so many other advantages as well (scalability, 
> > etc.).
> > 
> > Jiri did per-CPU recording patches a couple of months ago, not sure how usable they are at the 
> > moment?
> 
> it's still usable, I can rebase it and post a branch pointer,
> the problem is I haven't been able to find a case with a real
> performance benefit yet.. ;-)
> 
> perhaps because I haven't tried on server with really big cpu
> numbers

Maybe Alexey could pick up from there? Your concept looked fairly mature to me
and I tried it on a big-CPU box back then and there were real improvements.

Thanks,

	Ingo