From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: David Howells <dhowells@redhat.com>,
Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org,
linux-arch <linux-arch@vger.kernel.org>
Subject: Re: [PATCH 2/2] tracing: syscall_regfunc() should not skip kernel threads
Date: Tue, 19 Mar 2013 14:27:38 -0700 [thread overview]
Message-ID: <5148D84A.3090604@linux.intel.com> (raw)
In-Reply-To: <1363707396.5938.32.camel@gandalf.local.home>
On 03/19/2013 08:36 AM, Steven Rostedt wrote:
> On Tue, 2013-03-19 at 15:10 +0000, David Howells wrote:
>> Steven Rostedt <rostedt@goodmis.org> wrote:
>>
>>> Why? If we remove the tracepoint from the slowpath and use a table swap,
>>> then we wouldn't need to use the slowpath at all.
>>
>> How are you engineering a table swap? Do you patch the system call code to
>> change the immediate address loaded or do you put in a level of indirection?
>
> Patching the call site would probably be the easiest method.
>
> We've gotten pretty good at doing that ;-)
>
Yes, given that the machinery is already there we might as well use it.
-hpa
prev parent reply other threads:[~2013-03-19 21:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130317182834.GA22989@redhat.com>
2013-03-17 18:54 ` [PATCH 2/2] tracing: syscall_regfunc() should not skip kernel threads Steven Rostedt
2013-03-17 19:04 ` Oleg Nesterov
2013-03-17 19:04 ` Oleg Nesterov
2013-03-17 19:36 ` Steven Rostedt
2013-03-18 16:26 ` Oleg Nesterov
2013-03-18 16:26 ` Oleg Nesterov
2013-03-19 15:10 ` David Howells
2013-03-19 15:36 ` Steven Rostedt
2013-03-19 21:27 ` H. Peter Anvin [this message]
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