From: Mathieu Desnoyers <compudj@krystal.dyndns.org>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Martin Bligh <mbligh@google.com>,
"Frank Ch. Eigler" <fche@redhat.com>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
prasanna@in.ibm.com, Andrew Morton <akpm@osdl.org>,
Ingo Molnar <mingo@elte.hu>, Paul Mundt <lethal@linux-sh.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Jes Sorensen <jes@sgi.com>, Tom Zanussi <zanussi@us.ibm.com>,
Richard J Moore <richardj_moore@uk.ibm.com>,
Michel Dagenais <michel.dagenais@polymtl.ca>,
Christoph Hellwig <hch@infradead.org>,
Greg Kroah-Hartman <gregkh@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
William Cohen <wcohen@redhat.com>,
ltt-dev@shafik.org, systemtap@sources.redhat.com,
Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] Linux Kernel Markers 0.7 for 2.6.17 (with type checking!)
Date: Fri, 22 Sep 2006 02:11:00 -0000 [thread overview]
Message-ID: <20060922020119.GA28712@Krystal> (raw)
In-Reply-To: <451331A1.3020601@goop.org>
* Jeremy Fitzhardinge (jeremy@goop.org) wrote:
> Mathieu Desnoyers wrote:
> >+#ifdef CONFIG_MARK_SYMBOL
> >+#define MARK_SYM(name) \
> >+ do { \
> >+ __label__ here; \
> >+ here: asm volatile \
> >+ (MARK_KPROBE_PREFIX#name " = %0" : : "m" (*&&here));
> >\
> >+ } while(0)
> >+#else
> >+#define MARK_SYM(name)
> >+#endif
>
> BTW, this won't work if you put the MARK_SYM in a loop which gcc
> unrolls; you'll only get the mark in the last unrolled iteration
> (because the symbol assignments will override each other).
>
> Do make this work properly, you really need to put the mark entries into
> a separate section, so that if gcc duplicates the code, you get
> duplicated markers too.
>
Good point, I will change it to :
#define MARK_SYM(name) \
do { \
__label__ here; \
volatile static void *__mark_kprobe_##name \
asm (MARK_CALL_PREFIX#name) \
__attribute__((unused)) = &&here; \
here: \
do { } while(0); \
} while(0)
Which fixes the problem. Some tests showed me that the compiler does not unroll
an otherwise unrolled loop when this specific macro is called. (test done with
-funroll-all-loops).
Regards,
Mathieu
OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg
Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2006-09-22 2:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-22 0:01 Mathieu Desnoyers
[not found] ` <451331A1.3020601@goop.org>
2006-09-22 2:11 ` Mathieu Desnoyers [this message]
[not found] ` <45134539.7070305@goop.org>
2006-09-22 2:24 ` Mathieu Desnoyers
[not found] ` <45135FA0.1030403@goop.org>
2006-09-22 15:38 ` Mathieu Desnoyers
2006-09-22 2:49 ` Mathieu Desnoyers
[not found] ` <1160189237.21768.47.camel@localhost.localdomain>
2006-10-10 14:21 ` Proof of concept: Logdev with "almost-non" intrusive markers Mathieu Desnoyers
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=20060922020119.GA28712@Krystal \
--to=compudj@krystal.dyndns.org \
--cc=akpm@osdl.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=fche@redhat.com \
--cc=gregkh@suse.de \
--cc=hch@infradead.org \
--cc=jeremy@goop.org \
--cc=jes@sgi.com \
--cc=lethal@linux-sh.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ltt-dev@shafik.org \
--cc=masami.hiramatsu.pt@hitachi.com \
--cc=mbligh@google.com \
--cc=michel.dagenais@polymtl.ca \
--cc=mingo@elte.hu \
--cc=prasanna@in.ibm.com \
--cc=richardj_moore@uk.ibm.com \
--cc=systemtap@sources.redhat.com \
--cc=tglx@linutronix.de \
--cc=wcohen@redhat.com \
--cc=zanussi@us.ibm.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).