From: Arjan van de Ven <arjan@infradead.org>
To: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Arjan van de Ven <arjan@linux.intel.com>,
"K.Prasad" <prasad@linux.vnet.ibm.com>,
Alan Stern <stern@rowland.harvard.edu>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Jiri Slaby <jirislaby@gmail.com>, Li Zefan <lizf@cn.fujitsu.com>,
Avi Kivity <avi@redhat.com>, Mike Galbraith <efault@gmx.de>,
Masami Hiramatsu <mhiramat@redhat.com>,
Paul Mundt <lethal@linux-sh.org>, Jan Kiszka <jan.kiszka@web.de>
Subject: Re: [PATCH 1/6] perf/core: Provide a kernel-internal interface to get to performance counters
Date: Sun, 1 Nov 2009 21:38:39 -0800 [thread overview]
Message-ID: <20091101213839.28b4054a@infradead.org> (raw)
In-Reply-To: <19182.22063.788927.708332@cargo.ozlabs.ibm.com>
On Mon, 2 Nov 2009 14:46:55 +1100
Paul Mackerras <paulus@samba.org> wrote:
> Frederic Weisbecker writes:
>
> > /*
> > + * perf_event_create_kernel_counter
> > + * MUST be called from a kernel thread.
>
> Why? The reason for this requirement isn't obvious to me. It would
> be good to have the reason documented in the comment for the sake of
> people modifying the code in future.
because if you call it from another context it will attach to that
context... and go away when that context goes away...
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2009-11-02 5:37 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-24 14:16 [GIT PULL v2] hw-breakpoints: Rewrite on top of perf events Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 1/6] perf/core: Provide a kernel-internal interface to get to performance counters Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 2/6] x86/hw-breakpoints: Actually flush thread breakpoints in flush_thread() Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 3/6] perf/core: Add a callback to perf events Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 4/6] hw-breakpoints: Rewrite the hw-breakpoints layer on top of " Frederic Weisbecker
2009-10-24 16:19 ` Jan Kiszka
2009-10-25 23:31 ` Frederic Weisbecker
2009-10-26 8:17 ` Jan Kiszka
2009-11-01 21:09 ` [GIT PULL v3] hw-breakpoints: Rewrite " Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 1/6] perf/core: Provide a kernel-internal interface to get to performance counters Frederic Weisbecker
2009-11-02 3:46 ` Paul Mackerras
2009-11-02 5:38 ` Arjan van de Ven [this message]
2009-11-02 10:47 ` Paul Mackerras
2009-11-02 13:00 ` Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 2/6] x86/hw-breakpoints: Actually flush thread breakpoints in flush_thread() Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 3/6] perf/core: Add a callback to perf events Frederic Weisbecker
2009-11-02 3:49 ` Paul Mackerras
2009-11-02 13:01 ` Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 4/6] hw-breakpoints: Rewrite the hw-breakpoints layer on top of " Frederic Weisbecker
2009-11-01 22:09 ` Jan Kiszka
2009-11-01 22:49 ` Frederic Weisbecker
2009-11-01 23:37 ` Frederic Weisbecker
2009-11-02 7:45 ` Jan Kiszka
2009-11-02 13:04 ` Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 5/6] hw-breakpoints: Arbitrate access to pmu following registers constraints Frederic Weisbecker
2009-11-01 21:09 ` [PATCH 6/6] ksym_tracer: Remove KSYM_SELFTEST_ENTRY Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 5/6] hw-breakpoints: Arbitrate access to pmu following registers constraints Frederic Weisbecker
2009-10-24 14:16 ` [PATCH 6/6] ksym_tracer: Remove KSYM_SELFTEST_ENTRY Frederic Weisbecker
2009-10-24 14:19 ` [GIT PULL v2] hw-breakpoints: Rewrite on top of perf events Frederic Weisbecker
2009-10-26 21:31 ` K.Prasad
2009-10-29 19:07 ` Frederic Weisbecker
2009-11-02 6:25 ` K.Prasad
2009-11-02 14:07 ` Frederic Weisbecker
2009-11-04 14:14 ` K.Prasad
2009-11-05 11:02 ` Frederic Weisbecker
2009-11-03 19:11 [GIT PULL v4] hw-breakpoints: Rewrite on top of perf events v4 Frederic Weisbecker
2009-11-03 19:11 ` [PATCH 1/6] perf/core: Provide a kernel-internal interface to get to performance counters Frederic Weisbecker
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