linux-kernel - Re: [RFC][PATCH 0/8] perf pmu interface

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]

Date:	Wed, 16 Jun 2010 20:19:32 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	paulus <paulus@...ba.org>
Cc:	stephane eranian <eranian@...glemail.com>,
	Robert Richter <robert.richter@....com>,
	Will Deacon <will.deacon@....com>,
	Paul Mundt <lethal@...ux-sh.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Cyrill Gorcunov <gorcunov@...il.com>,
	Lin Ming <ming.m.lin@...el.com>,
	Yanmin <yanmin_zhang@...ux.intel.com>,
	Deng-Cheng Zhu <dengcheng.zhu@...il.com>,
	David Miller <davem@...emloft.net>,
	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>
Subject: Re: [RFC][PATCH 0/8] perf pmu interface

On Wed, 2010-06-16 at 18:00 +0200, Peter Zijlstra wrote:
> These patches prepare the perf code for multiple pmus (no user
> interface yet, Lin Ming is working on that). These patches remove all
> weak functions and rework the struct pmu interface.
> 
> The latter is inspired by the work Frederic is doing to to filter out
> IRQ contexts.
> 
> These patches are very prelimenary, they haven't seen a compiler yet and
> the last patch still needs sparc,ppc and arm converted.
> 
> But they patches seem to be in a good enough shape to see what people
> think..

Another idea I was kicking about was to push find_get_context()
partially into struct pmu, so that we can have context's per pmu.

For cpu-wide contexts its easy, for per-task contexts we need more
pointers in task_struct, so I was thinking of something like:

enum {
  perf_swevent_context = 0,
  perf_cpu_context,
#ifdef HW_BREAKPOINT
  perf_bp_context,
#endif
  perf_nr_task_context
};

struct task_struct {
  ...
  struct perf_event_context *perf_event_ctxs[perf_nr_task_context];
  ...
};

and have add for loops over the struct pmu list for the cpu-wide
contexts and for loops over perf_nr_task_context for the task contexts.

It would add some extra code to the hot-paths, but its the best I can
come up with.
--
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/