linux-kernel - Re: [PATCH V4] perf: event preserve and create across cpu hotplug

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: <20190618122329.GE3419@hirez.programming.kicks-ass.net>
Date:   Tue, 18 Jun 2019 14:23:29 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Mukesh Ojha <mojha@...eaurora.org>
Cc:     linux-kernel@...r.kernel.org,
        Raghavendra Rao Ananta <rananta@...eaurora.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Alexei Starovoitov <ast@...nel.org>
Subject: Re: [PATCH V4] perf: event preserve and create across cpu hotplug

On Tue, Jun 18, 2019 at 02:24:51PM +0530, Mukesh Ojha wrote:
> Perf framework doesn't allow preserving CPU events across
> CPU hotplugs. The events are scheduled out as and when the
> CPU walks offline. Moreover, the framework also doesn't
> allow the clients to create events on an offline CPU. As
> a result, the clients have to keep on monitoring the CPU
> state until it comes back online.
> 
> Therefore,

That's not a therefore. There's a distinct lack of rationale here. Why
do you want this?