From: Teresa Johnson <tejohnson@google.com>
To: Steven Bosscher <stevenb.gcc@gmail.com>
Cc: Jan Hubicka <hubicka@ucw.cz>,
reply@codereview.appspotmail.com, davidxl@google.com,
gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Add working-set size and hotness information to fdo summary (issue6465057)
Date: Mon, 20 Aug 2012 17:44:00 -0000 [thread overview]
Message-ID: <CAAe5K+Vg0w==rP+AuMVdTC3xCr6sF6U38xR=a5aZ6U_7R=5r4g@mail.gmail.com> (raw)
In-Reply-To: <CABu31nMgm9mOHGziNj7WxMQ0uF-t3WPikHeG56O4Y_7dJPSEPQ@mail.gmail.com>
On Mon, Aug 20, 2012 at 8:35 AM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> On Mon, Aug 20, 2012 at 11:48 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>>> The summary merging in coverage.c confuses me a bit as it seems to be
>>> handling the case when there are multiple program summaries in a
>>> single gcda file. When would this happen? It looks like the merge
>>> handling in libgcov should always produce a single program summary per
>>> gcda file.
>
> AFAIU it merges existing profile data with new profile data from a
> second (or third, or ...) trial run.
It looks like libgcov will always merge program summaries between
different runs though. As far as I can tell, it will always either
rewrite the whole gcda file with a single merged program summary, or
abort the write if the merge was not successful. However, the comment
above gcov_exit does talk about keeping program summaries separate for
object files contained in different programs, which is what Honza was
describing as the motivation for the coverage.c merging. But I don't
see where multiple program summaries ever get written to the same gcda
file - if the checksums are different it seems to abort the write. But
the code in coverage.c is dealing with a single gcda file containing
multiple program summaries. Is there code somewhere that will cause
this to happen?
Thanks,
Teresa
>
> Ciao!
> Steven
--
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
next prev parent reply other threads:[~2012-08-20 17:44 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-16 14:22 Teresa Johnson
2012-08-18 8:20 ` Jan Hubicka
2012-08-20 4:59 ` Teresa Johnson
2012-08-20 5:41 ` Xinliang David Li
2012-08-20 9:48 ` Jan Hubicka
2012-08-20 14:53 ` Teresa Johnson
2012-08-20 17:05 ` Xinliang David Li
2012-08-20 15:36 ` Steven Bosscher
2012-08-20 17:44 ` Teresa Johnson [this message]
2012-08-20 17:52 ` Steven Bosscher
2012-08-20 16:57 ` Xinliang David Li
2012-08-20 19:03 ` Andi Kleen
2012-08-20 19:58 ` Xinliang David Li
2012-08-21 1:27 ` Jan Hubicka
2012-08-21 5:14 ` Teresa Johnson
2012-08-21 5:29 ` Jan Hubicka
2012-08-21 6:15 ` Xinliang David Li
2012-08-21 6:33 ` Jan Hubicka
2012-08-21 7:15 ` Xinliang David Li
2012-08-21 7:34 ` Jan Hubicka
2012-08-21 17:10 ` Xinliang David Li
[not found] ` <CAAe5K+XeEc68t9g57UosvX6YoWnVthV2iwgfdjk=zys7vep+SA@mail.gmail.com>
[not found] ` <CAAkRFZK=AGWpjoxM2z8aBaepBX-FoQfZEFfYvDqfGmwmnDW8KA@mail.gmail.com>
2012-08-22 1:56 ` Jan Hubicka
2012-08-22 5:34 ` Teresa Johnson
2012-08-22 6:18 ` Jan Hubicka
2012-08-23 2:07 ` Teresa Johnson
2012-08-23 2:29 ` Jan Hubicka
2012-08-21 14:59 ` Andi Kleen
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