From: Hans Rosenfeld <hans.rosenfeld@amd.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: <hpa@zytor.com>, <tglx@linutronix.de>,
<suresh.b.siddha@intel.com>, <eranian@google.com>,
<brgerst@gmail.com>, <robert.richter@amd.com>,
<Andreas.Herrmann3@amd.com>, <x86@kernel.org>,
<linux-kernel@vger.kernel.org>, <bebl@mageta.org>
Subject: Re: [PATCH 0/9] rework of extended state handling, LWP support
Date: Fri, 16 Dec 2011 17:07:58 +0100 [thread overview]
Message-ID: <20111216160757.GL665@escobedo.osrc.amd.com> (raw)
In-Reply-To: <20111205102223.GA3143@elte.hu>
On Mon, Dec 05, 2011 at 11:22:23AM +0100, Ingo Molnar wrote:
>
> * Hans Rosenfeld <hans.rosenfeld@amd.com> wrote:
>
> > These patches were built and tested against 3.1. The older RFC
> > patches that have been lingering in tip/x86/xsave for the last
> > few months should be removed.
>
> They have been lingering because of negative review feedback i
> have given to you about LWP. I'm not convinced about the current
> form of abstraction that this patch-set offers.
>
> See this past discussion from half a year ago:
>
> Subject: Re: [RFC v3 0/8] x86, xsave: rework of extended state handling, LWP support
>
> We can and should do better than that.
We had an intern, Benjamin Block, working on perf support for LWP until
a few weeks ago. Because of the fundamental problem that it is not
reasonably possible to allocate virtual memory for a process from a
different process' context, the code only supports self-monitoring.
This allows a process to control LWP through the perf syscalls. Instead
of using malloc() and the LLWPCB instruction itself, it can use the perf
syscall to have the perf kernel code do it. It can also use perf to get
at the raw LWP samples instead of just reading them from the LWP buffer.
I'll send you Benjamins code as an RFC patch set, so please take a look
at it and tell me what you think about it. I admit I don't understand
every detail of it yet as I've only recently started to work my way
through it, and I have no prior knowledge about perf.
Hans
next prev parent reply other threads:[~2011-12-16 16:08 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-29 12:41 [PATCH 0/9] rework of extended state handling, LWP support Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 1/9] x86, xsave: warn on #NM exceptions caused by the kernel Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 2/9] x86, xsave: cleanup fpu/xsave support Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 3/9] x86, xsave: cleanup fpu/xsave signal frame setup Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 4/9] x86, xsave: rework fpu/xsave support Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 5/9] x86, xsave: remove unused code Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 6/9] x86, xsave: more cleanups Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 7/9] x86, xsave: remove lazy allocation of xstate area Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 8/9] x86, xsave: add support for non-lazy xstates Hans Rosenfeld
2011-11-29 12:41 ` [PATCH 9/9] x86, xsave: add kernel support for AMDs Lightweight Profiling (LWP) Hans Rosenfeld
2011-11-29 21:31 ` [PATCH 0/9] rework of extended state handling, LWP support Andi Kleen
2011-11-30 17:37 ` Hans Rosenfeld
2011-11-30 21:52 ` Andi Kleen
2011-12-01 20:36 ` Hans Rosenfeld
2011-12-02 2:01 ` H. Peter Anvin
2011-12-02 11:20 ` Hans Rosenfeld
2011-12-07 19:57 ` Hans Rosenfeld
2011-12-07 20:00 ` [PATCH 7/8] x86, xsave: add support for non-lazy xstates Hans Rosenfeld
2011-12-07 20:00 ` [PATCH 8/8] x86, xsave: add kernel support for AMDs Lightweight Profiling (LWP) Hans Rosenfeld
2011-12-05 10:22 ` [PATCH 0/9] rework of extended state handling, LWP support Ingo Molnar
2011-12-16 16:07 ` Hans Rosenfeld [this message]
2011-12-16 16:12 ` [RFC 1/5] x86, perf: Implement software-activation of lwp Hans Rosenfeld
2011-12-16 16:12 ` [RFC 2/5] perf: adds prototype for a new perf-context-type Hans Rosenfeld
2011-12-16 16:12 ` [RFC 3/5] perf: adds a new pmu-initialization-call Hans Rosenfeld
2011-12-16 16:12 ` [RFC 4/5] x86, perf: implements lwp-perf-integration (rc1) Hans Rosenfeld
2011-12-18 8:04 ` Ingo Molnar
2011-12-18 15:22 ` Benjamin Block
2011-12-18 23:43 ` Ingo Molnar
2011-12-19 9:09 ` Robert Richter
2011-12-19 10:54 ` Ingo Molnar
2011-12-19 11:12 ` Avi Kivity
2011-12-19 11:40 ` Ingo Molnar
2011-12-19 11:58 ` Avi Kivity
2011-12-19 18:13 ` Benjamin
2011-12-20 8:56 ` Ingo Molnar
2011-12-20 9:15 ` Ingo Molnar
2011-12-20 9:47 ` Avi Kivity
2011-12-20 10:09 ` Ingo Molnar
2011-12-20 15:27 ` Joerg Roedel
2011-12-20 18:40 ` Ingo Molnar
2011-12-21 0:07 ` Joerg Roedel
2011-12-21 12:34 ` Ingo Molnar
2011-12-21 12:44 ` Avi Kivity
2011-12-21 13:22 ` Ingo Molnar
2011-12-21 22:49 ` Joerg Roedel
2011-12-23 10:53 ` Ingo Molnar
2011-12-21 11:46 ` Gleb Natapov
2011-12-23 10:56 ` Ingo Molnar
2011-12-20 15:48 ` Vince Weaver
2011-12-20 18:27 ` Ingo Molnar
2011-12-20 22:47 ` Vince Weaver
2011-12-21 12:00 ` Ingo Molnar
2011-12-21 13:55 ` Vince Weaver
2011-12-16 16:12 ` [RFC 5/5] x86, perf: adds support for the LWP threshold-int Hans Rosenfeld
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20111216160757.GL665@escobedo.osrc.amd.com \
--to=hans.rosenfeld@amd.com \
--cc=Andreas.Herrmann3@amd.com \
--cc=bebl@mageta.org \
--cc=brgerst@gmail.com \
--cc=eranian@google.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=robert.richter@amd.com \
--cc=suresh.b.siddha@intel.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.