From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
kan.liang@linux.intel.com, like.xu@linux.intel.com,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: [PATCH] perf/arch: Remove perf_sample_data::regs_user_copy
Date: Fri, 30 Oct 2020 08:33:58 -0400 [thread overview]
Message-ID: <20201030083358.4c771278@oasis.local.home> (raw)
In-Reply-To: <20201030105917.GI2611@hirez.programming.kicks-ass.net>
On Fri, 30 Oct 2020 11:59:17 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Oct 30, 2020 at 11:26:01AM +0100, Thomas Gleixner wrote:
> > What's worse is perf_sample_data which is 384 bytes and is 64 bytes aligned.
>
> Here; this shrinks it to 192 bytes. Combined with the static dummy this
> should reduce stack usage by 360 bytes.
>
> ---
> Subject: perf/arch: Remove perf_sample_data::regs_user_copy
>
> struct perf_sample_data lives on-stack, we should be careful about it's
> size. Furthermore, the pt_regs copy in there is only because x86_64 is a
> trainwreck, solve it differently.
>
> Halves sizeof(perf_sample_data).
>
>
I tested with just this patch and it doesn't crash when running
function tracing and perf simultaneously.
-- Steve
next prev parent reply other threads:[~2020-10-30 12:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-30 4:27 [BUG] Stack overflow when running perf and function tracer Steven Rostedt
2020-10-30 9:00 ` Peter Zijlstra
2020-10-30 10:26 ` Thomas Gleixner
2020-10-30 10:32 ` Peter Zijlstra
2020-10-30 11:36 ` Thomas Gleixner
2020-10-30 13:42 ` Thomas Gleixner
2020-10-30 10:59 ` [PATCH] perf/arch: Remove perf_sample_data::regs_user_copy Peter Zijlstra
2020-10-30 12:33 ` Steven Rostedt [this message]
2020-10-30 11:19 ` [PATCH] perf/x86: Make dummy_iregs static Peter Zijlstra
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=20201030083358.4c771278@oasis.local.home \
--to=rostedt@goodmis.org \
--cc=kan.liang@linux.intel.com \
--cc=like.xu@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
/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
all inboxes | Powered by JetHome®