linux-kernel - Re: [RFC][PATCH 3/9] perf: export registerred pmus via sysfs

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:	Tue, 11 May 2010 11:24:37 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Lin Ming <ming.m.lin@...el.com>,
	Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	"eranian@...il.com" <eranian@...il.com>,
	"Gary.Mohr@...l.com" <Gary.Mohr@...l.com>,
	"arjan@...ux.intel.com" <arjan@...ux.intel.com>,
	"Zhang, Yanmin" <yanmin_zhang@...ux.intel.com>,
	Paul Mackerras <paulus@...ba.org>,
	"David S. Miller" <davem@...emloft.net>,
	Russell King <rmk+kernel@....linux.org.uk>,
	Paul Mundt <lethal@...ux-sh.org>,
	lkml <linux-kernel@...r.kernel.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Will Deacon <will.deacon@....com>,
	Maynard Johnson <mpjohn@...ibm.com>,
	Carl Love <carll@...ibm.com>
Subject: Re: [RFC][PATCH 3/9] perf: export registerred pmus via sysfs

On Tue, 2010-05-11 at 11:18 +0200, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@...radead.org> wrote:
> 
> > The new PMUs will use a dynamic range that starts at PERF_TYPE_MAX.
> 
> I dont think we should use a dynamic range of event sources - it's a 
> completely useless indirection that has no meaning to humans.
> 
> As far as machine interfaces go a much cleaner approach would be to allow an 
> open fd to a sysfs file to be passed to sys_perf_event_open() - this would 
> identify the event source. This needs a small extension of the ABI but we 
> could thus get rid of the 'type' enumeration altogether and express _all_ 
> event sources via fds to sysfs files.

Whatever, that's almost identical. What we can do is reserve
perf_event_attr::type with bit 31 set for fd's and use the fd->file
lookup instead of the type->pmu lookup.
--
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/