linux-kernel - Re: [announce] Performance Counters for Linux, v6

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:	Sat, 21 Feb 2009 00:24:53 +0100
From:	stephane eranian <eranian@...glemail.com>
To:	Corey Ashford <cjashfor@...ux.vnet.ibm.com>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Eric Dumazet <dada1@...mosbay.com>,
	Robert Richter <robert.richter@....com>,
	Arjan van de Ven <arjan@...radead.org>,
	Peter Anvin <hpa@...or.com>, Paul Mackerras <paulus@...ba.org>,
	"David S. Miller" <davem@...emloft.net>,
	Mike Galbraith <efault@....de>
Subject: Re: [announce] Performance Counters for Linux, v6

On Sat, Feb 21, 2009 at 12:04 AM, Corey Ashford
<cjashfor@...ux.vnet.ibm.com> wrote:
>
>
> Peter Zijlstra wrote:
>>
>> On Fri, 2009-02-20 at 14:38 -0800, Corey Ashford wrote:
>>>
>>> There may be other non-event-related changes that will not be handled
>>> quite as well in this way.  In the original email I hinted at that we may
>>> want an option for mmap'd sample buffers at some point, and so I'm not clear
>>> how you'd provide an ABI to request mmap'd buffers (you would probably need
>>> to be able to request the size and get back a pointer to the mmap'd buffer).
>>>  Would this be done through a special sys_perf_counter_open call?  Or
>>> through a subsequent ioctl call on the group leader after an open (which
>>> requires the counters to be initially disabled), etc.
>>
>> What's stopping a regular mmap() call using the fd obtained from
>> sys_perf_counter_open() ?
>
> Perhaps nothing.  I don't know why it didn't occur to me that this could be
> done.  If PCL supports this, great!
>
That has always been the way, I thought this could be done with PCL.
Except that I don't know who decides the size of the mmap().
--
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/