[Pixman] testsuite fails on power7

[Siarhei Siamashka]

On Mon, 30 Sep 2013 10:08:17 -0400
"Lennart Sorensen" <lsorense at csclub.uwaterloo.ca> wrote:

> On Sat, Sep 28, 2013 at 10:16:12PM +0300, Siarhei Siamashka wrote:
> > Could you please give the following patches a try in your problematic
> > configuration on power7?
> > 
> >     http://lists.freedesktop.org/archives/pixman/2013-September/002969.html
> > 
> > They are also available here:
> > 
> >     https://github.com/ssvb/pixman/commits/20130927-vmx-fix-unaligned-writes
> 
> OK, I applied your two patches for the vmx code, and I also added the
> new thread-test that was posted.
> 
> Everything passed.
> 
> I think you nailed it.  Yay!

Good. Thanks for testing.

> Before:
> 
> Making check in test
> make[2]: Entering directory `/root/pixman-0.26.0/build/test'
> make  check-TESTS
> make[3]: Entering directory `/root/pixman-0.26.0/build/test'
> PASS: a1-trap-test
> PASS: pdf-op-test
> PASS: region-test
> PASS: region-translate-test
> PASS: fetch-test
> PASS: oob-test
> PASS: trap-crasher
> PASS: alpha-loop
> PASS: scaling-crash-test
> PASS: scaling-helpers-test
> PASS: gradient-crash-test
> region_contains test passed (checksum=D2BF8C73)
> PASS: region-contains-test
> PASS: alphamap
> PASS: stress-test
> composite traps test passed (checksum=E3112106)
> PASS: composite-traps-test
> blitters test passed (checksum=A364B5BF)
> PASS: blitters-test
> /bin/bash: line 5: 30817 Segmentation fault      ${dir}$tst
> FAIL: scaling-test
> /bin/bash: line 5: 30863 Segmentation fault      ${dir}$tst
> FAIL: affine-test
> PASS: composite
> =============================================
> 2 of 19 tests failed
> Please report to pixman at lists.freedesktop.org
> =============================================
> make[3]: *** [check-TESTS] Error 1
> make[3]: Leaving directory `/root/pixman-0.26.0/build/test'
> make[2]: *** [check-am] Error 2
> make[2]: Leaving directory `/root/pixman-0.26.0/build/test'
> make[1]: *** [check-recursive] Error 1
> make[1]: Leaving directory `/root/pixman-0.26.0/build'
> dh_auto_test: make -j24 check returned exit code 2
> make: *** [build] Error 29
> 
> After:
> 
> Making check in test
> make[2]: Entering directory `/root/pixman-0.26.0.new/build/test'
> make  check-TESTS
> make[3]: Entering directory `/root/pixman-0.26.0.new/build/test'
> PASS: a1-trap-test
> PASS: pdf-op-test
> PASS: region-test
> PASS: region-translate-test
> PASS: fetch-test
> PASS: oob-test
> PASS: trap-crasher
> PASS: alpha-loop
> Skipped thread-test - pthreads not supported
> PASS: thread-test
> PASS: scaling-crash-test
> PASS: scaling-helpers-test
> PASS: gradient-crash-test
> region_contains test passed (checksum=D2BF8C73)
> PASS: region-contains-test
> PASS: alphamap
> PASS: stress-test
> composite traps test passed (checksum=E3112106)
> PASS: composite-traps-test
> blitters test passed (checksum=A364B5BF)
> PASS: blitters-test
> scaling test passed (checksum=80DF1CB2)
> PASS: scaling-test
> affine test passed (checksum=1EF2175A)
> PASS: affine-test
> PASS: composite
> ===================
> All 20 tests passed
> ===================
> make[3]: Leaving directory `/root/pixman-0.26.0.new/build/test'
> make[2]: Leaving directory `/root/pixman-0.26.0.new/build/test'
> make[2]: Entering directory `/root/pixman-0.26.0.new/build'
> make[2]: Leaving directory `/root/pixman-0.26.0.new/build'
> make[1]: Leaving directory `/root/pixman-0.26.0.new/build'

It is generally preferred to use an up to date version of pixman. It
usually has better performance and is covered by more tests (which in
theory should mean less bugs). Currently in pixman git we already
have 27 tests for the tests suite, and you only have 20.

But the VMX/Altivec code has not seen updates for ages, so you can
safely apply the vmx fixes to pixman-0.26 if you really have to
use it.

Also the current status of performance optimizations in pixman for
PowerPC platform is not really great. It seriously suffers from the
generic C fast paths having higher priority than the vmx optimized
combiners for some really important operations. A significant
performance improvement for PowerPC is a relatively low hanging
fruit if somebody is up for this task. Hopefully with the recent
    http://www-03.ibm.com/press/us/en/pressrelease/41926.wss
announcement, PowerPC may come back to life again :)

-- 
Best regards,
Siarhei Siamashka