From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 9CC7D385DC35; Fri, 29 May 2020 09:11:12 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9CC7D385DC35
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1590743472;
 bh=f6voSdaWPtDT+/Yzp+WDxggiYteulhDsytiztASoc7M=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=Vd9gsNfZ1EU+sElclp8g05Bb8KOk2VMlgWrn0tcqxRMnXo+ZAfRcYCYzyLvolMG7h
 yU0yYIIxfZuGMfdznMxJqj0R5L/AAS5Xb0CMmkcXiS6nGPapYorUiI74umFccSarO+
 ZBV4V75nc6ABcbu/GeBdbV7+6nuAgfFkmVkvURBs=
From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug gcov-profile/95348] GCC records zero functions and modules in
 the profiling data file, ICC does NOT
Date: Fri, 29 May 2020 09:11:12 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: gcov-profile
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: marxin at gcc dot gnu.org
X-Bugzilla-Status: WAITING
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: marxin at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 11.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status
Message-ID: <bug-95348-4-LY8Z7JmIBT@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-95348-4@http.gcc.gnu.org/bugzilla/>
References: <bug-95348-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <http://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <http://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Fri, 29 May 2020 09:11:12 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95348

Martin Li=C5=A1ka <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |WAITING

--- Comment #7 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
Ok, I spent some time thinking about your workload and I would recommend the
following steps:

1) You should not generate profile data for each process to a different fol=
der,
but rather merge it.

GCC PGO bootstrap contains ~500 .gcda files where the process is executed
~2000x.
Note that .gcda file merging happens per-file and the file is locked. It sh=
ould
be a reasonable small window that can delay parallel process execution.

2) I would like to know how long does one process run and what portion is s=
pent
in merging (and dumping) of a profile.

3) You may consider shrinking training run, 10.000 executions seems like a
massive training run to me.

4) GCDA file format is not ideal and can be simply and rapidly shrank by e.=
g.
gzip. For GCC PGO, it shrinks 10x.

Please provide as much information about the workload so that we can find a
feasible solution.=