| 2017-02-23 17:40:52 |
Gustavo Serra Scalet |
bug |
|
|
added bug |
| 2017-02-24 15:52:13 |
Brian Murray |
tags |
regression-release |
regression-release yakkety |
|
| 2017-02-24 15:53:04 |
Brian Murray |
bug watch added |
|
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854053 |
|
| 2017-02-24 15:53:04 |
Brian Murray |
bug task added |
|
coreutils (Debian) |
|
| 2017-02-24 15:53:20 |
Brian Murray |
coreutils (Ubuntu): assignee |
|
Matthias Klose (doko) |
|
| 2017-02-25 04:20:44 |
Bug Watch Updater |
coreutils (Debian): status |
Unknown |
Fix Released |
|
| 2017-02-28 09:17:43 |
Matthias Klose |
nominated for series |
|
Ubuntu Yakkety |
|
| 2017-02-28 09:17:43 |
Matthias Klose |
bug task added |
|
coreutils (Ubuntu Yakkety) |
|
| 2017-02-28 09:17:43 |
Matthias Klose |
nominated for series |
|
Ubuntu Xenial |
|
| 2017-02-28 09:17:43 |
Matthias Klose |
bug task added |
|
coreutils (Ubuntu Xenial) |
|
| 2017-02-28 09:31:07 |
Matthias Klose |
coreutils (Ubuntu): status |
New |
Fix Released |
|
| 2017-03-02 15:48:31 |
Gustavo Serra Scalet |
description |
Dear Maintainer,
The sha256sum provided by coreutils (without openssl) is performing
poorly with gcc versions >= 4.9 until 7.0 (currently under development).
The reason for that is the -fschedule-insns optimization that is used
with -O2. By simply deactivating it, there is a performance improvement
of 2 to 3 times.
I'm using Ubuntu 16.10 and the coreutils package version 8.25-2ubuntu2.
Please check the following closed debian bug report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854053
Be aware of the following conditions that are required:
* If ppc64le
* If gcc being used is >= 4.9 and < 7.0
Notes:
1) gcc-7 is not affected by this bug (verified on 20170129 snapshot).
2) clang is not affected by this bug (verified on v3.8 and v3.9).
3) strangely the sha512 is not affected by this.
Below a demonstration of how it performs on my POWER8 machine:
===================================================
$ (./configure && make -j9) > /dev/null && time src/sha256sum ~/ubuntu-16.10-server-ppc64el.iso
configure: WARNING: libacl development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without ACL support.
configure: WARNING: libattr development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without xattr support.
configure: WARNING: libcap library was not found or not usable.
configure: WARNING: GNU coreutils will be built without capability support.
configure: WARNING: libgmp development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without GMP support.
src/who.c: In function 'print_user':
src/who.c:454:20: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
int *a = utmp_ent->ut_addr_v6;
^~~~~~~~
d14bdb413ea6cdc8d9354fcbc37a834b7de0c23f992deb0c6764d0fd5d65408e /home/gut/ubuntu-16.10-server-ppc64el.iso
real 0m18.670s
user 0m16.566s
sys 0m0.745s
$ # now with the following patch: ## Check Michael Stone's patch for an improved version.
$ diff Makefile.in ../Makefile.in
8989c8989
< @am__fastdepCC_TRUE@ $(COMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
---
> @am__fastdepCC_TRUE@ $(COMPILE) $$([ "$@" == "lib/sha256.o" ] && echo "-fno-schedule-insns") -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
$ cp ../Makefile.in Makefile.in
$ (./configure && make -j9) > /dev/null && time src/sha256sum ~/ubuntu-16.10-server-ppc64el.iso
configure: WARNING: libacl development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without ACL support.
configure: WARNING: libattr development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without xattr support.
configure: WARNING: libcap library was not found or not usable.
configure: WARNING: GNU coreutils will be built without capability support.
configure: WARNING: libgmp development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without GMP support.
src/who.c: In function 'print_user':
src/who.c:454:20: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
int *a = utmp_ent->ut_addr_v6;
^~~~~~~~
d14bdb413ea6cdc8d9354fcbc37a834b7de0c23f992deb0c6764d0fd5d65408e /home/gut/ubuntu-16.10-server-ppc64el.iso
real 0m5.903s
user 0m5.560s
sys 0m0.255s |
[Impact]
* Performance drop of 2x-3x on ppc64le when using sha256sum
* Please backport this bug to last LTS as this application is widely used.
* This fix is due to a optimization issue found on gcc v4.9 to gcc v7.0.
[Test Case]
* Run sha256sum with a big file and measure the time it takes. The patch improves this timing up to 3 times faster.
[Regression Potential]
* This patch is specifically for the sha256.o object, affecting only this binary.
[Other Info]
Michael Stone's improved patch:
Index: coreutils-8.26/Makefile.in
===================================================================
--- coreutils-8.26.orig/Makefile.in 2016-11-30 13:34:55.000000000 -0500
+++ coreutils-8.26/Makefile.in 2017-02-22 07:18:55.352394058 -0500
@@ -14661,6 +14661,10 @@
$(TEST_LOGS): $(PROGRAMS)
+ifeq ($(DEB_TARGET_ARCH), ppc64el)
+lib/sha256.o: CFLAGS+=-fno-schedule-insns
+endif
+
# Tell versions [3.59,3.63) of GNU make to not export all variables.
# Otherwise a system limit (for SysV at least) may be exceeded.
.NOEXPORT:
Original bug description:
The sha256sum provided by coreutils (without openssl) is performing
poorly with gcc versions >= 4.9 until 7.0 (currently under development).
The reason for that is the -fschedule-insns optimization that is used
with -O2. By simply deactivating it, there is a performance improvement
of 2 to 3 times.
I'm using Ubuntu 16.10 and the coreutils package version 8.25-2ubuntu2.
Please check the following closed debian bug report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854053
Be aware of the following conditions that are required:
* If ppc64le
* If gcc being used is >= 4.9 and < 7.0
Notes:
1) gcc-7 is not affected by this bug (verified on 20170129 snapshot).
2) clang is not affected by this bug (verified on v3.8 and v3.9).
3) strangely the sha512 is not affected by this.
Below a demonstration of how it performs on my POWER8 machine:
===================================================
$ (./configure && make -j9) > /dev/null && time src/sha256sum ~/ubuntu-16.10-server-ppc64el.iso
configure: WARNING: libacl development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without ACL support.
configure: WARNING: libattr development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without xattr support.
configure: WARNING: libcap library was not found or not usable.
configure: WARNING: GNU coreutils will be built without capability support.
configure: WARNING: libgmp development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without GMP support.
src/who.c: In function 'print_user':
src/who.c:454:20: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
int *a = utmp_ent->ut_addr_v6;
^~~~~~~~
d14bdb413ea6cdc8d9354fcbc37a834b7de0c23f992deb0c6764d0fd5d65408e /home/gut/ubuntu-16.10-server-ppc64el.iso
real 0m18.670s
user 0m16.566s
sys 0m0.745s
$ # now with the following patch: ## Check Michael Stone's patch for an improved version.
$ diff Makefile.in ../Makefile.in
8989c8989
< @am__fastdepCC_TRUE@ $(COMPILE) -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
---
> @am__fastdepCC_TRUE@ $(COMPILE) $$([ "$@" == "lib/sha256.o" ] && echo "-fno-schedule-insns") -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ $< &&\
$ cp ../Makefile.in Makefile.in
$ (./configure && make -j9) > /dev/null && time src/sha256sum ~/ubuntu-16.10-server-ppc64el.iso
configure: WARNING: libacl development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without ACL support.
configure: WARNING: libattr development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without xattr support.
configure: WARNING: libcap library was not found or not usable.
configure: WARNING: GNU coreutils will be built without capability support.
configure: WARNING: libgmp development library was not found or not usable.
configure: WARNING: GNU coreutils will be built without GMP support.
src/who.c: In function 'print_user':
src/who.c:454:20: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
int *a = utmp_ent->ut_addr_v6;
^~~~~~~~
d14bdb413ea6cdc8d9354fcbc37a834b7de0c23f992deb0c6764d0fd5d65408e /home/gut/ubuntu-16.10-server-ppc64el.iso
real 0m5.903s
user 0m5.560s
sys 0m0.255s |
|
| 2017-03-02 18:00:34 |
Brian Murray |
coreutils (Ubuntu Yakkety): status |
New |
Fix Committed |
|
| 2017-03-02 18:00:36 |
Brian Murray |
bug |
|
|
added subscriber Ubuntu Stable Release Updates Team |
| 2017-03-02 18:00:39 |
Brian Murray |
bug |
|
|
added subscriber SRU Verification |
| 2017-03-02 18:00:48 |
Brian Murray |
tags |
regression-release yakkety |
regression-release verification-needed yakkety |
|
| 2017-03-02 18:01:33 |
Brian Murray |
coreutils (Ubuntu Xenial): status |
New |
Fix Committed |
|
| 2017-03-03 17:14:52 |
Gustavo Serra Scalet |
tags |
regression-release verification-needed yakkety |
regression-release verification-done yakkety |
|
| 2017-03-27 07:33:00 |
Robie Basak |
tags |
regression-release verification-done yakkety |
regression-release verification-done-yakkety yakkety |
|
| 2017-03-27 07:33:18 |
Launchpad Janitor |
coreutils (Ubuntu Yakkety): status |
Fix Committed |
Fix Released |
|
| 2017-03-27 07:33:23 |
Robie Basak |
removed subscriber Ubuntu Stable Release Updates Team |
|
|
|
| 2017-06-26 19:29:23 |
Ubuntu Foundations Team Bug Bot |
tags |
regression-release verification-done-yakkety yakkety |
regression-release removal-candidate verification-done-yakkety yakkety |
|
| 2017-06-26 19:54:10 |
Gustavo Serra Scalet |
tags |
regression-release removal-candidate verification-done-yakkety yakkety |
regression-release verification-done-xenial verification-done-yakkety yakkety |
|
| 2017-06-27 11:04:58 |
Matthias Klose |
tags |
regression-release verification-done-xenial verification-done-yakkety yakkety |
regression-release verification-done verification-done-xenial verification-done-yakkety yakkety |
|
| 2017-06-28 11:59:50 |
Gustavo Serra Scalet |
tags |
regression-release verification-done verification-done-xenial verification-done-yakkety yakkety |
regression-release verification-done-xenial verification-done-yakkety yakkety |
|
| 2017-07-07 00:13:58 |
Launchpad Janitor |
coreutils (Ubuntu Xenial): status |
Fix Committed |
Fix Released |
|
