From: Steven Rostedt <rostedt@goodmis.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Junxuan Liao <ljx@cs.wisc.edu>,
linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"Paul E. McKenney" <paulmck@kernel.org>
Subject: Re: [PATCH] x86/tracing: introduce enter/exit tracepoint pairs for page faults
Date: Mon, 14 Apr 2025 16:57:36 -0400 [thread overview]
Message-ID: <20250414165736.77415836@gandalf.local.home> (raw)
In-Reply-To: <214abd94-7fb3-4515-a1ae-a60abe81af88@intel.com>
On Mon, 14 Apr 2025 13:42:23 -0700
Dave Hansen <dave.hansen@intel.com> wrote:
> On 4/14/25 13:35, Junxuan Liao wrote:
> > Rename page_fault_{user,kernel} to page_fault_{user,kernel}_enter, and
> > add the exit counterparts. This might be useful for measuring page fault
> > handling latencies.
>
> Is there a reason kprobes don't work for this?
Kprobes is not always easy to add, and it does add more overhead.
I use to have measurements by using function graph tracing of all timings
into the kernel, but when the noinstr was added, that broke. I still do
timings but that's by manually adding hacks into the kernel. I haven't done
timings on a vanilla kernel for some time. It would be nice to be able to
do that again.
-- Steve
next prev parent reply other threads:[~2025-04-14 20:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-14 20:35 [PATCH] x86/tracing: introduce enter/exit tracepoint pairs for page faults Junxuan Liao
2025-04-14 20:42 ` Dave Hansen
2025-04-14 20:57 ` Steven Rostedt [this message]
2025-04-14 23:14 ` Junxuan Liao
2025-04-14 23:22 ` Junxuan Liao
2025-04-14 23:37 ` Dave Hansen
2025-04-14 23:43 ` Steven Rostedt
2025-04-14 23:48 ` Junxuan Liao
2025-04-14 20:54 ` Borislav Petkov
2025-04-14 22:20 ` Steven Rostedt
2025-04-15 1:23 ` Junxuan Liao
2025-04-16 17:47 ` Borislav Petkov
2025-04-16 18:01 ` Steven Rostedt
2025-04-16 18:06 ` Steven Rostedt
2025-04-18 21:39 ` Borislav Petkov
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=20250414165736.77415836@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=ljx@cs.wisc.edu \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=paulmck@kernel.org \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox