linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	live-patching@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>, Jiri Slaby <jslaby@suse.cz>,
	Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC PATCH 10/10] x86/unwind: add undwarf unwinder
Date: Thu, 1 Jun 2017 07:36:09 -0500	[thread overview]
Message-ID: <20170601123609.ku5zq2huhlneq2dn@treble> (raw)
In-Reply-To: <20170601121356.5yoeq74el77sewoo@hirez.programming.kicks-ass.net>

On Thu, Jun 01, 2017 at 02:13:56PM +0200, Peter Zijlstra wrote:
> So we do that lookup for every single frame. That's going to hurt.
> 
> Would it make sense to cache the last 'module' in an attempt to at least
> avoid that lookup again? Something like so:

The only thing with caching the module is, what if the module goes away?

Based on your previous comment I was thinking I would disable preemption
for the entire unwind_next_frame() step, but not *between* steps.  I
suppose we could require the unwind caller to disable preemption but I'd
like to avoid that if possible.

-- 
Josh

  reply	other threads:[~2017-06-01 12:36 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-01  5:44 [RFC PATCH 00/10] x86: undwarf unwinder Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 01/10] objtool: move checking code to check.c Josh Poimboeuf
2017-06-14  7:22   ` Jiri Slaby
2017-06-01  5:44 ` [RFC PATCH 02/10] objtool, x86: add several functions and files to the objtool whitelist Josh Poimboeuf
2017-06-14  7:24   ` Jiri Slaby
2017-06-14 13:03     ` Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 03/10] objtool: stack validation 2.0 Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 04/10] objtool: add undwarf debuginfo generation Josh Poimboeuf
2017-06-14  8:42   ` Jiri Slaby
2017-06-14 13:27     ` Josh Poimboeuf
2017-06-22  7:47       ` Jiri Slaby
2017-06-22 12:49         ` Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 05/10] objtool, x86: add facility for asm code to provide CFI hints Josh Poimboeuf
2017-06-01 13:57   ` Andy Lutomirski
2017-06-01 14:16     ` Josh Poimboeuf
2017-06-01 14:40       ` Andy Lutomirski
2017-06-01 15:02         ` Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 06/10] x86/entry: add CFI hint undwarf annotations Josh Poimboeuf
2017-06-01 14:03   ` Andy Lutomirski
2017-06-01 14:23     ` Josh Poimboeuf
2017-06-01 14:28       ` Josh Poimboeuf
2017-06-01 14:39         ` Andy Lutomirski
2017-06-01 15:01           ` Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 07/10] x86/asm: add CFI hint annotations to sync_core() Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 08/10] extable: rename 'sortextable' script to 'sorttable' Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 09/10] extable: add undwarf table sorting ability to sorttable script Josh Poimboeuf
2017-06-01  5:44 ` [RFC PATCH 10/10] x86/unwind: add undwarf unwinder Josh Poimboeuf
2017-06-01 11:05   ` Peter Zijlstra
2017-06-01 12:26     ` Josh Poimboeuf
2017-06-01 12:47       ` Jiri Slaby
2017-06-01 13:02         ` Josh Poimboeuf
2017-06-01 13:42         ` Peter Zijlstra
2017-06-01 13:10       ` Peter Zijlstra
2017-06-01 12:13   ` Peter Zijlstra
2017-06-01 12:36     ` Josh Poimboeuf [this message]
2017-06-01 13:12       ` Peter Zijlstra
2017-06-01 15:03         ` Josh Poimboeuf
2017-06-14 11:45   ` Jiri Slaby
2017-06-14 13:44     ` Josh Poimboeuf
2017-06-01  6:08 ` [RFC PATCH 00/10] x86: " Ingo Molnar
2017-06-01 11:58   ` Josh Poimboeuf
2017-06-01 12:17     ` Peter Zijlstra
2017-06-01 12:33       ` Jiri Slaby
2017-06-01 12:52         ` Josh Poimboeuf
2017-06-01 12:57           ` Jiri Slaby
2017-06-01 12:47       ` Josh Poimboeuf
2017-06-01 13:25         ` Peter Zijlstra
2017-06-06 14:14           ` Sergey Senozhatsky
2017-06-01 13:50         ` Andy Lutomirski
2017-06-01 13:50     ` Ingo Molnar
2017-06-01 13:58       ` Jiri Slaby
2017-06-02  8:30         ` Jiri Slaby
2017-06-01 14:05       ` Josh Poimboeuf
2017-06-01 14:08       ` Jiri Slaby
2017-06-02 10:40         ` Mel Gorman

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=20170601123609.ku5zq2huhlneq2dn@treble \
    --to=jpoimboe@redhat.com \
    --cc=hpa@zytor.com \
    --cc=jslaby@suse.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=live-patching@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=torvalds@linux-foundation.org \
    --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;
as well as URLs for NNTP newsgroup(s).