== This week ==
* Applied patch for doing NEON high/low extraction using subregs.
Ramana pointed out that we do the same thing for insertion,
so I wrote a patch to handle that too. Both now merged into
Linaro sources.
* Looked at ARM bootstrap problem on trunk. Turned out to be
an aliasing problem. Submitted and applied patch.
* Reworked part of my SMS register-scheduling patch after feedback
from Ayal. Submitted new version upstream.
* Got SPEC2006 running on the powerpc boxes and tested one part
of my -fsched-pressure patch. Bit of a mixed bag. h264ref was
one of the worst sufferers, which was a bit worrying. I think
I'll need to make a third change too.
To recap, there are two pieces now:
1) Make -fsched-pressure honour the DFA
2) Make -fsched-pressure allow values that are live across a
loop to be spilled.
I naively hoped that (1) would be OK on its own, but h264 shows
that the current -fsched-pressure code is very conservative
when it comes to large blocks. It only considers register
deaths once there is a single remaining use; if there are two
unscheduled uses, it assumes that the register remains live
for the rest of the block.
So the problem that (1) was fixing was that -fsched-pressure was too
optimistic in terms of what it could schedule in a cycle. But with
that fixed, we seem to have too many sources of pessimism...
Richard
== GDB ==
* Worked on support for cross-platform core file generation.
* Followed up on patch to support disabling address space
randomization in gdbserver.
== GCC ==
* Followed up on patch for PR 50305.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
* Working on croos-compiling Firefox. Getting dependencies in place and
setting up the configuration file (.mozconfig). I have had the strategy to
fix one dependency at a time, picking prebuilt packages or building my self.
Michael told me at yesterday's meeting about multistrap, that could possibly
be used for fixing all dependencies at once. I will look into that next
week.
* During this process I have also spent some time reading up on cross
compilation in general and also on autoconf and the GNU build system.
Best Regards
Åsa
== String routines ==
* Got eglibc testing setup happy at last
- Note that -O3 builds generally seem to give a few more errors
that are probably worth looking at
- -march=armv6 -mthumb hit some non-thumb1 instructions (normally
non-lo registers), again worth looking at
- Cross testing to Qemu user mode often stalls, mostly on nptl
tests that abort/fail when run in system/natively
* Sent new version of eglibc/memchr patch upstream
* Now have working newlib test setup and reference set
- next step is to try adding my memchr there
== Other ==
* Testing a QEmu patch with Peter
* Looking at bug 861296 (difference in mmap layouts)
* Adding a few suggestions to the set of cpu hotplug tests.
* Dealing with the Manchester lab cold.
Short week; back on Monday
Dave
== GDB ==
* Committed hardware watchpoint support for gdbserver to mainline,
including two minor changes resulting from review comments;
backported those fixes to Linaro GDB as well.
* Implemented and tested support for disabling address space
randomization in gdbserver; patch posted for review.
* Investigated support for cross-platform core file generation.
== GCC ==
* Patch review week.
* Posted updated patch for PR 50305.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
Arnd Bergmann <arnd(a)arndb.de> wrote on 08/26/2011 04:44:26 PM:
> On Thursday 25 August 2011, Russell King - ARM Linux wrote:
> >
> > Arnd, can you test this to make sure your gdb test case still works,
and
> > Mark, can you test this to make sure it fixes your problem please?
>
> Hi Russell,
>
> The patch in question was not actually from me but from Ulrich Weigand,
> so he's probably the right person to test your patch.
> I'm forwarding it in full to Uli for reference.
Hi Arnd, hi Russell,
sorry for the late reply, I've just returned from vacation today ...
I've not yet run the test, but just from reading through the patch
it seems that this will at least partially re-introduce the problem
my original patch was trying to fix.
The situation here is about GDB performing an "inferior function
call", e.g. via the GDB "call" command. To do so, GDB will:
0. [ Have gotten control of the target process via some ptrace
intercept previously, and then ... ]
1. Save the register state
2. Create a dummy frame on the stack and set up registers (PC, SP,
argument registers, ...) as appropriate for a function call
3. Restart via PTRACE_CONTINUE
[ ... at this point, the target process runs the function until
it returns to a breakpoint instruction and GDB gets control
again via another ptrace intercept ... ]
4. Restore the register state saved in [1.]
5. At some later point, continue the target process [at its
original location] with PTRACE_CONTINUE
The problem now occurs if at point [0.] the target process just
happened to be blocked in a restartable system call. For this
sequence to then work as expected, two things have to happen:
- at point [3.], the kernel must *not* attempt to restart a
system call, even though it thinks we're stopped in a
restartable system call
- at point [5.], the kernel now *must* restart the originally
interrupted system call, even though it thinks we're stopped
at some breakpoint, and not within a system call
My patch achieved both these goals, while it would seem your
patch only solves the first issue, not the second one. In
fact, since any interaction with ptrace will always cause the
TIF_SYS_RESTART flag to be *reset*, and there is no way at all
to *set* it, there doesn't appear to be any way for GDB to
achive that second goal.
[ With my patch, that second goal was implicitly achieved by
the fact that at [1.] GDB would save a register state that
already corresponds to the way things should be for restarting
the system call. When that register set is then restored in [4.],
restart just happens automatically without any further kernel
intervention. ]
One way to fix this might be to make the TIF_SYS_RESTART flag
itself visible to ptrace, so the GDB could save/restore it
along with the rest of the register set; this would be similar
to how that problem is handled on other platforms. However,
there doesn't appear to be an obvious place for the flag in
the ptrace register set ...
Bye,
Ulrich
== String routines ==
* Having got agreement on ignoring the triplet for picking the
routine, I'm just testing a patch,
but fighting a qemu setup.
* Found the binfmt binding for armeb was wrong (runs the le
version); filed bug with fix in
Dave
==GCC==
Combined report for last 2 weeks -
===Progress===
* Committed conditional compares patch to Linaro GCC 4.6
* Looking at modelling auto-inc-decs better .
* Tried patch for PR19599 and that broke bootstrap with a segfault.
Needs some re-engineering.
* Looked at the latest bootstrap failure on trunk. Still narrowing down.
* Some work on some administrative stuff
* Bit of patch review.
* Went for LLVM dev meeting.
* Release week had a few issues and helped dry-run cbuild spawns of
jobs and think I now know how to do that.
=== Plans ===
* finish looking at bootstrap failure.
* Finish auto-inc-dec patch.
* some more patch review.
* Send out LLVM dev meeting report.
Absences.
* 5th October - Out of office.
* 13th -14th October - Internal ARM training.
* 31st Oct - 4th Nov - Linaro Summit Orlando
* 08 Nov - 11 Nov - Tentatively booked
* Dec 19 - 31st Dec - Tentatively booked
(short week: 4 days)
RAG:
Red:
Amber:
Green:
Current Milestones:
|| || Planned || Estimate || Actual ||
||add-omap3-networking || 2011-10-13 || 2011-10-13 || ||
||a15-systemmode-planning || 2011-10-13 || 2011-10-13 || 2011-09-22 ||
||a15-usermode-support || 2011-11-10 || 2011-11-10 || ||
||upstream-omap3-cleanup || 2011-11-10 || 2011-11-10 || ||
Historical Milestones:
||qemu-linaro 2011-04 || 2011-04-21 || 2011-04-21 || 2011-04-21 ||
||qemu-linaro 2011-05 || 2011-05-19 || 2011-05-19 || n/a ||
||close out 1105 blueprints || 2011-05-28 || 2011-05-28 || 2011-05-19 ||
||complete 1111 planning || 2011-05-28 || 2011-05-28 || 2011-05-27 ||
||qemu-linaro-2011-06 || 2011-06-16 || 2011-06-16 || 2011-06-16 ||
||qemu-linaro-2011-07 || 2011-07-21 || 2011-07-21 || 2011-07-21 ||
||qemu-linaro 2011-08 || 2011-08-18 || 2011-08-18 || 2011-08-18 ||
||qemu-linaro 2011-09 || 2011-09-15 || 2011-09-15 || 2011-09-15 ||
== a15-system-mode-planning ==
* now complete: we have generated blueprints/roadmap cards for the TSC
for the various options
== a15-usermode-support ==
* tested udiv/sdiv implementation
* fused mac: rough idea of what needs to be done, need to get all
the fiddly details right
== omap3 upstreaming ==
* rebased and sent pullreq for various outstanding patches
== other ==
* code/design walkthrough for upstream's new memoryregion API
* working on lightning talk for pdsw doughnut session next week
* investigated compile failure building QEMU in thumb mode with debug
enabled (we're trying to use the Thumb framepointer register as a
temporary...)
* meetings: toolchain, standup, 1-2-1
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences (to end of year):
Sep 29-Oct 07, Oct 17, Nov 21, Dec 15-Jan 03: leave
Oct 30-Nov 04: Linaro Connect Q4.11
== This week ==
* Submitted a fix for the performance regression caused by my
arm_comparison_operator patch. Applied upstream after approval
from Ramana (thanks). Will backport to Linaro towards the end
of next week if there are no reported problems.
* Went back to looking at -fsched-pressure. To recap, a colleague
ran SPEC for s390 comparing:
(a) normal -O3 based flags
(b) (a) + -fsched-pressure without my patch
(c) (a) + -fsched-pressure with my patch
(c) got the best geomean result, but there were some individual
tests for which (b) was significantly worse than (a), and for
which (c) only partly closed the gap.
Found one problem. It looks like -fsched-pressure only really
operates on the issue rate and instruction latencies; it doesn't
seem to use the DFA. This seems to be unintentional, and fixing
it showed some nice results.
Also, the -fsched-pressure patch that I wrote at Connect set the
starting pressure based on the set of registers that are both live
on entry to the block _and_ used within the enclosing loop,
This still seems to be a bit too conservative, in that it makes
the scheduler go out of its way to preserve loop invariants,
even if there are too many of them. Experimented with changing
"used" to "defined". This too seemed to be a win.
* Got access to some PowerPC GNU/Linux machines that are suitable
for running SPEC. Set up my account there and got SPEC building.
The idea is to use this to get more cross-target evidence for the
-fsched-pressure submission(s).
* Discussion about the SMS register-scheduling patches after great
feedback from Ayal. While drafting a still-unsent reply justifying
the main part of the patch, I found I was also explaining why another
part of the patch (specifically the prologue/epilogue part) was wrong.
Thought about that a bit today.
* Submitted fix for LP 641126.
== Next week ==
* More SMS register scheduling.
* More -fsched-pressure.
* Hopefully remerge the arm_comparison_operator patch with this week's fix.
Richard
* Working on getting everything in place for cross-compiling Firefox for
ARM. Trying to understand how the configuration script and make file works.
* Working on a test that will run Sunspider and extract the results. The
challenging part is that results are only presented on the page, not e.g.
written to stdout or to file. My approach to create an html file, embed the
page with the test in an iframe, and read out the results when the test is
done.
* Running SPEC2K on the Snowball board. An updated kernel solved the issue
with great variations in the test results. Some tests results look a bit
strange, so I will look at what those tests do to see what part of the
system is stressed.
Best Regards
Åsa
Hi,
* widening shifts patch - submitted upstream
* change default vector size patch - submitted to linaro-gcc
* automatic choice of vector size for basic block vectorization - testing
* vectorizer bug fixes
Next week we have New Year holiday on Wednesday (half day) and Thursday.
Ira
The Linaro Toolchain Working Group is pleased to announce the 2011.09
release of both Linaro GCC 4.6 and Linaro GCC 4.5.
Linaro GCC 4.6 2011.09-1 is the seventh release in the 4.6 series. Based
off the latest GCC 4.6.1+svn178681, it contains a range of vectoriser
and core performance improvements as well as fixing a number of
bugs.
Interesting changes include:
* Updates to 4.6.1+svn178681
* Improves performance by making better use of conditional compares
* Improves performance by properly scheduling widening multiplies
* Improves size and speed by improving constant generation in Thumb-2
* Implements support for widening multiples in toe core
* Improves vectorised code by reducing the over-promotion of intermediates
* Improves performance by reducing redundant moves between VFP and ARM
* Finishes off supporting the Android team in integrating Linaro GCC
Fixes:
* LP: #823548 Can't use -flto with skia
* LP: #823711 libvirt version 0.9.2-4ubuntu8 failed to build on armel
* LP: #827990 internal compiler error: in decode_addr_const, at varasm.c:2632
* LP: #836401 ICE on a | (b << negative-constant)
* LP: #838994 ICE building perl w/ -marm
* LP: #843775 ICE optimizing widening multiply-and-accumulate
Linaro GCC 4.5 2011.09 is the fourteenth release in the 4.5
series. Based off the latest GCC 4.5.3+svn178560, this is a
maintenance focused release.
Interesting changes in 4.5 include:
* Updates to 4.5.3+svn178560
Fixes:
* LP: #823711 libvirt version 0.9.2-4ubuntu8 failed to build on armel
The source tarballs are available from:
https://launchpad.net/gcc-linaro/+milestone/4.6-2011.09https://launchpad.net/gcc-linaro/+milestone/4.5-2011.09
Downloads are available from the Linaro GCC page on Launchpad:
https://launchpad.net/gcc-linaro
More information on the features and issues are available from the
release page:
https://launchpad.net/gcc-linaro/4.6/4.6-2011.09https://launchpad.net/gcc-linaro/4.5/4.5-2011.09
Mailing list: http://lists.linaro.org/mailman/listinfo/linaro-toolchain
Bugs: https://bugs.launchpad.net/gcc-linaro/
Questions? https://ask.linaro.org/
Interested in commercial support? inquire at support(a)linaro.org
-- Michael
I tried to bootstrap current GCC trunk and our latest gcc-linaro-4.6
in profile guided, link time optimisation, and SMS modes. The results
are here:
https://wiki.linaro.org/MichaelHope/Sandbox/PGOLTOSMSStatus1
Short story: you can't bootstrap in LTO or PGO on ARM as they run out
of memory. i686 LTO is broken on trunk and gcc-linaro-4.6. SMS is
fine in general.
I'll run these once a week and keep an eye on them. A -fwhopr instead
of -flto may help on ARM. I don't know why the PGO build runs out of
memory.
-- Michael
Måns pointed me at the IDCT throughput test that's included with
libav. I've written up a page on how to build and run it at:
https://wiki.linaro.org/MichaelHope/Sandbox/LibAvDCT
Included are results with and without the vectoriser. In all cases
the vectoriser improves things, including increasing the SIMPLE-C
version by 11 % and the peak by 17 %.
The coefficient of variance is low so the results are consistent. I
haven't investigated the benchmark itself to see if its valid - we
could be vectorising the loop overhead instead of the IDCT itself.
-- Michael
Please coordinate with Jon Masters at RedHat/Fedora and Adam Conrad at
Ubuntu/Debian on this. (Cc'ing the cross-distro list, through which the
recent ARM summit at Linux Plumbers was organized.)
Cheers,
- Michael
On Sep 16, 2011 8:41 AM, "David Gilbert" <david.gilbert(a)linaro.org> wrote:
> OK, so we seem to have agreement here that what we want is autodetect
> for eglibc and
> forget about the triplet; well technically that probably makes my life
> easier, and I don't
> think it's too hard a sell.
>
> Dave
>
> _______________________________________________
> linaro-toolchain mailing list
> linaro-toolchain(a)lists.linaro.org
> http://lists.linaro.org/mailman/listinfo/linaro-toolchain
* Linaro GCC
Spun 4.5 and 4.6 2011.09 GCC release tarballs. Uploaded them to
Michael's server, and kicked off the tests.
Continued work on my new constant optimization experiments. I now have
it tracking all the constants and am looking at how to detect the
optimization opportunities. So far it only calculates how exprensive it
would be to generate a value by adding to an existing constant, which is
a start at least. I'm having difficulties detecting whether changing an
insn will make it's parent (dependency-wise) obsolete, or not (and
therefore whether to count its costs - there's no problem for
instructions that overwrite an entire register, but ones that write to
portions of registers (such as MOVT) make more complex dependency
chains, and the def-use chains don't seem to be sorted into the order of
use.
* Other
Half day vacation on Thursday.
* Added testcases to Richard's micro benchmarks taken from libav.
* Discussed with Ayal the new version of the patch to support
instructions with
REG_INC_NOTE in SMS which causes bootstrap failure. I intend to debug
the bootstrap failure in order to find the cause for it.
(http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01216.html)
== String routines ==
* Tidying up bits of cortex strings for the release process
* Nailing down the behaviour of config.sub and the config systems in
gcc, binutils and eglibc
== Other ==
* A discussion on synchronisation primitives on various CPUs that
started on the gcc list
- looking at http://www.cl.cam.ac.uk/~pes20/cpp/cpp0xmappings.html
- pointing out the 64bit instructions
- asking why they used isb's when neither the kernel or gcc use
them (answer the DMBs should
be fine as well, but there is some debate over which is
quicker, oh and DMBs are
converted to slower dsb's on most A9s due to an errata).
* Looking for docs on the non-core bits of current SoCs
* Extracting some denbench stats from a few months back for Ramana
About a day of non-Linaro IBM stuff.
Dave
RAG:
Red:
Amber:
Green:
NB: since qemu-linaro releases demonstrably go out on schedule
every month I'm dropping them from the milestone tables in these
reports, in favour of blueprint completion dates (usually they'll
be planned for dates coinciding with a qemu-linaro release).
Current Milestones:
|| || Planned || Estimate || Actual ||
||add-omap3-networking || 2011-10-13 || 2011-10-13 || ||
||a15-systemmode-planning || 2011-10-13 || 2011-10-13 || ||
||a15-usermode-support || 2011-11-10 || 2011-11-10 || ||
||upstream-omap3-cleanup || 2011-11-10 || 2011-11-10 || ||
Historical Milestones:
||qemu-linaro 2011-04 || 2011-04-21 || 2011-04-21 || 2011-04-21 ||
||qemu-linaro 2011-05 || 2011-05-19 || 2011-05-19 || n/a ||
||close out 1105 blueprints || 2011-05-28 || 2011-05-28 || 2011-05-19 ||
||complete 1111 planning || 2011-05-28 || 2011-05-28 || 2011-05-27 ||
||qemu-linaro-2011-06 || 2011-06-16 || 2011-06-16 || 2011-06-16 ||
||qemu-linaro-2011-07 || 2011-07-21 || 2011-07-21 || 2011-07-21 ||
||qemu-linaro 2011-08 || 2011-08-18 || 2011-08-18 || 2011-08-18 ||
||qemu-linaro 2011-09 || 2011-09-15 || 2011-09-15 || 2011-09-15 ||
== linaro-qemu-11.11 ==
* completed this month's release
== add-omap3-networking ==
* investigated why qemu's usb-net model didn't work on the beagle;
this was due to a bug in the usb-ohci controller model; patches
sent upstream. Fix will go into qemu-linaro 2011-10.
== a15-system-mode-planning ==
* wrote up options and my suggestion on the wiki:
https://wiki.linaro.org/PeterMaydell/QemuA15
* just need to discuss with Michael and turn this into a roadmap entry
== a15-usermode-support ==
* complete but untested implementation of UDIV and SDIV
* fused multiply-accumulate: implemented decode, and the special-cases
parts of the softfloat implementation (NaN, inf, etc); the difficult
bit of actually implementing the operation remains
== other ==
* meetings: toolchain, pdsw doughnuts, AFDS
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences (to end of year):
Sep 19, Sep 29-Oct 07, Oct 17, Nov 21, Dec 15-Jan 03: leave
Oct 30-Nov 04: Linaro Connect Q4.11
As mentioned on the standup call this morning, I've been trying to get my head
around the way different parts of the toolchain using the config scripts and the
triplets. I'd appreciate some thoughts on what the right thing to do
is, especially
since there was some unease at some of the ideas.
My aim here is to add an armv7 specific set of routines to the eglibc
ports and get this picked up
only when eglibc is built for armv7; but it's getting a bit tricky.
eglibc shares with gcc and binutils a script called config.sub (that
lives in a separate repository)
which munges the triplet into a $basic_machine and validates it for a
set of known
triplets.
So for example it has the (shell) pattern:
arm | arm[bl]e | arme[lb] | armv[2345] | armv[345][lb]
to recognise triplets of the form arm- armbe- armle-
armel- armbe- armv5- armv5l- or armv5b-
It also knows more obscure things such as if you're configuring for
a netwinder it's an armv4l- system running linux - but frankly most
of that type of thing are a decade or two out of date. Note it doesn't
yet know about armv6 or armv7.
eglibc builds a search path that at the moment includes a path under
the 'ports' directory of the form
arm/eabi/$machine
where $machine is typically the first part of your triplet; however
at the moment eglibc doesn't have any ARM version specific subdirectories.
If I just added an ports/sysdeps/arm/eabi/armv7 directory it wouldn't
use it because
it searches in arm/eabi/arm if configured with the triplet arm-linux-gnueabi or
--with-cpu sets $submachine (NOT $machine) - so if you pass --with-cpu=armv7
it ends up searching
arm/eabi/arm/armv7
if you used the triplet arm-linux-gnueabi. If you had a triplet like
armel then I think
it would be searching
arm/eabi/armel/armv7
So my original patch (
http://old.nabble.com/-ARM--architecture-specific-subdirectories,-optimised…
)
did the following:
* Modified the paths searched to be arm/eabi (rather than arm/eabi/$machine)
* If $submachine hadn't been set by --with-cpu then autodetect it
from gcc's #defines
which meant that it ignored the start of the triplet and let you
specify --with-cpu=armv7
After some discussion with Joseph Myers, he's convinced me that isn't
what eglibc
is expecting (see later in the thread linked above); what it should
be doing is that
$machine should be armv7 and $submachine should be used if we wanted
say a cortex-a8 or
cortext-a9 specific version.
My current patch:
* adds armv6 and armv7 to config.sub
* adds arm/eabi/armv7 and arm/eabi/armv6t2 and one assembler
routine in there.
* If $machine is just 'arm' then it autodetects from gcc's #defines
* else if $machine is armv.... then that's still $machine
So if you use:
a triplet like arm-linux-gnueabi it looks at gcc and if that's configured
for armv7-a it searches arm/eabi/armv7
a triplet like armv7-linux-gnueabi then it searches arm/eabi/armv7
irrespective
of what gcc was configured for
a triplet like armv7-linux-gnueabi and --with-cpu=cortex-a9 then it searches
arm/eabi/armv7/cortex-a9 then arm/eabi/armv7
As far as I can tell gcc ignores the first part of the triplet, other than
noting it's arm and spotting if it ends with b for big endian; (i.e.
configuring gcc with armv4-linux-gnueabi and armv7-linux-gnueabi
ends up with the same compiler).
binutils also mostly ignores the 1st part of the triple - although is
a bit of a mess
with different parts parsing it differently (it seems to spot arm9e for some odd
reason); as far as I can tell gold will accept armbe* for big endian where as
ld takes arm*b !
If you're still reading, then the questions are:
1) Does the approach I've suggested make sense - in particular that the
machine directory chosen is based either on the triplet or where the triplet
doesn't specify the configuration of gcc; that's my interpretation of what
Joseph is suggesting.
2) Doing (1) would seem to suggest I should give config.sub armv6t2 and
some of the other complex names.
Dave
== This week ==
* Reviewed patches for the release.
* ...then broke the release. Tried to spin a new one.
* Worked on a "real" fix for bug 850099. Now in testing.
* Looked more at auto-inc-dec stuff. Saw a case that didn't behave
as I expected on the A9. The A9 TRM doesn't describe what happens
for post-indexed addressing, so I asked Ramana. Apparently the
behaviour is expected. Once I have more info, I'll try to update
the patches.
* Worked on neon-highlow-extract and neon-strided-load-extract.
Posted the three patches upstream. Nicely, the one I thought
was going to be the most controversial actually got positive
feedback from Paolo (who wrote the affected code).
Richard
== GDB ==
* Completed hardware watchpoint support for gdbserver.
* Tracked down watchpoint resource accounting regression
on GDB mainline (not present in 7.3).
* Created and published Linaro GDB 7.3-2011.09 release.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
* Running SPEC2K on the Snowball board. A fresh kernel with HIGHMEM enabled
made it possible to run the tests. Great variations in the results indicates
that something strange is going on. Turning off one of the CPU:s gives
stable result (but slow), so my current guess is that the variations are
caused by a known bug that makes one cpu run slower.
http://igloocommunity.org/bugzilla3/show_bug.cgi?id=1
The patch for this bug was not included in my kernel. Will have another go
with a kernel where the patch is included, as a background activity.
* Planned and started working on the "Adding browsing benchmarks to our
current set of tests"-activity. I will try to keep documentation up to date
here:
https://wiki.linaro.org/AsaSandahl/Sandbox/BrowsingBenchmarks
Experimenting with building Firefox in different ways, so far for x86.
Best Regards
Åsa
(bouncing to linaro-dev as it's generally interesting)
On Fri, Sep 16, 2011 at 8:17 AM, Ramana Radhakrishnan
<ramana.radhakrishnan(a)linaro.org> wrote:
> Hi,
>
> I've been looking at some of the perf regressions we've been seeing
> these days in an attempt to understand what's going on in these cases.
> While I can use perf and get more statistics and do other things to
> figure out why there are perf regressions between 2 binaries along
> with perf record and report, I wonder if it is possible to use u-boot
> to accurately measure what's going on. I would like to try and get the
> values of the performance counters between 2 program points .
>
> I am aware that there are patches that are floating around that allow
> users to set and reset the PMU counters by allowing user level access
> to it in the kernel : while that maybe useful to some I'm not sure if
> I want to take a chance with some other process getting scheduled that
> ends up getting scheduled. Even if there are parts of the kernel that
> save and restore PMU counters associated per process with across
> context switches . I'm looking for as accurate measurements as
> possible in this case and I wonder if u-boot is the best bet for this
> ( in the absence of any dedicated hardware debug / trace unit) given
> not all of us have one.
>
>
> At the minimum to do this I believe we require u-boot or some start-up code to:
>
> * Turn on i-cache and d-cache. ( The current u-boot for panda that I
> get from the linaro-uboot git repo
> git://git.linaro.org/boot/u-boot-linaro-stable.git says "Warning
> Caches turned off" when starting up ). Googling around I find a few
> patches floating around that turn on the d-cache in August from Aneesh
> at TI . We should consider getting these in at some point.
>
> * Looking in $(UBOOT_TOP)/examples/api I see that there are simple
> printf routines and simple stand-alone applications that exist which
> could be used for this purpose. The one problem with this is the fact
> that u-boot appears to require use of -ffixed-r8 for it's purposes
> which *might* mean we need these if we were to use API calls into
> standard u-boot functions .
I wonder if R8 is used in the current ARM version? There's no reason
we can't cherry pick parts such as the serial I/O out into a library
and make the app completely self contained. Skip all of the
initialisation stuff and assume the boot loader has done it for you.
> * Turn on / off speculative prefetching - I believe the kernel does
> this already for a few boards, but could this be done in u-boot just
> before it launches a test application ?
>
> * Turn on the VFP and Neon units.
>
> * Turn on unaligned access so that unaligned accesses are allowed in
> the test applications. GCC will now move towards generating unaligned
> accesses on versions of the architecture that support it, the patches
> upstream have now been approved.
>
> * Memory map / linker scripts to make sure we are putting things in
> the right places (sigh, has to be per-board).
But everything goes in RAM so you have one generic linker script and a
per board MEMORY definition. Similar to:
http://bazaar.launchpad.net/~stm32f-dev/stm32f-dev/stm32f-startup/view/head…
...but even lighter.
> We then write a set of library functions that could then look at what
> performance counters are of interest to us and track them by resetting
> them to 0 and making sure they haven't overflown.
>
> Has anyone else in the group played with u-boot before or has any
> thoughts in this direction ? I am not suggesting that we do this work
> right now but it sounds like an interesting thought of where we can
> get to with this.
My worry is that we miss turning on a feature and get results that
aren't representative. That should be easy enough to check by
baselineing against a Linux hosted run.
We can use NFS or kermit to load the programs. u-boot has a network
console which is nice when you don't have serial. This combined with
an expect script (or LAVA? Paul?) should automate the whole process.
-- Michael
Hi,
* put the sources of the libunwind android port, the patches for
debuggerd and the Android test app online
* documented things at:
https://wiki.linaro.org/WorkingGroups/ToolChain/Outputs/LibunwindDebuggerd
* noticed differences between the old (debuggerd) and the new
(debuggerd+libunwind) backtraces
* I'm still not sure what's going on (maybe they are adding offsets
or something)
* however, the backtrace that libunwind does looks sane to me
Note: I'll be on vacation till October 7th.
Regards
Ken
Hi,
* testing widen-shifts patch on ARM
* SLP improvements:
- submitted a patch to allow not simple ivs in SLP
- committed a patch to allow read-after-read dependencies in SLP
Ira
The Linaro Toolchain Working Group is pleased to announce the release
of Linaro QEMU 2011.09.
Linaro QEMU 2011.09 is the latest monthly release of
qemu-linaro. Based off upstream (trunk) QEMU, it includes a
number of ARM-focused bug fixes and enhancements.
New in this month's release:
- linux-user mode now supports the 64 bit cmpxchg kernel helpers
(only needed for applications compiled for ARMv6 or lower)
- PL111 display controller now supported; this fixes a problem
where BGR was interpreted as RGB on recent versatilepb kernels
Plus a few other minor bug fixes and the usual round of upstream
fixes and improvements.
Known issues:
- The beagle and beaglexm models still do not support USB networking;
we intend to fix this for the 2011.10 release
- There may be some problems with running multithreaded programs in
linux-user mode (LP:823902)
The source tarball is available at:
https://launchpad.net/qemu-linaro/+milestone/2011.09
Binary builds of this qemu-linaro release are being prepared and
will be available shortly for users of Ubuntu. Packages will be in
the linaro-maintainers tools ppa:
https://launchpad.net/~linaro-maintainers/+archive/tools/
More information on Linaro QEMU is available at:
https://launchpad.net/qemu-linaro
The Linaro Toolchain Working Group is pleased to announce the release
of Linaro GDB 7.3.
Linaro GDB 7.3 2011.09 is the second release in the 7.3 series. Based
off the latest GDB 7.3, it includes a number of ARM-focused bug fixes
and enhancements.
This release contains:
* Support for hardware breakpoints and watchpoints in gdbserver
The source tarball is available at:
https://launchpad.net/gdb-linaro/+milestone/7.3-2011.09
More information on Linaro GDB is available at:
https://launchpad.net/gdb-linaro
Hi there. The 2011.09 release has been spun and is testing up well.
The 4.5 and 4.6 branches are now open so feel free to commit any
approved patches.
-- Michael
Hi!
When building Android with the Linaro toolchain, I encountered this link
time error when going from gcc 4.4.3 to gcc 4.6.
"arm-eabi-g++: error: unrecognized option '-avoid-version'"
I find several posts about people encountering the same thing for different
programs.
Was this option removed? Anyone know the story behind it?
Regards
Åsa
Release Management needs the list of the the blueprints that will be
delivered this month.
For each bp, they want a Headline and Acceptance criteria. The Headline is a
statement to include in the Monthly release announcement. The acceptance
criteria is a statement how to verify the work is done.
I have collected this month's blueprints in the spreadsheet, please review
it for accuracy. If a blueprint you are working on is missing, please add
it.
The Headline and Acceptance can be added into the whiteboard as follows:
Headline:
headline text
Acceptance:
acceptance text
Once you add the the headline and acceptance, please modify the spreadsheet
to reflect that it is done.
https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AoZqvK7R1biJdGxSc…
Thanks in advance,
Mounir
--
Mounir Bsaibes
Project Manager
Follow Linaro.org:
facebook.com/pages/Linaro/155974581091106http://twitter.com/#!/linaroorghttp://www.linaro.org/linaro-blog <http://www.linaro.org/linaro-blog>
==GCC==
===Progress===
* Fixed https://bugs.launchpad.net/ubuntu/+source/gcc-4.6/+bug/838994
. Investigated Bernd's alternate patch . Will commit mine.
* Looked at PR48308 for sometime whihc might be a dup of PR50313 .
* Some blueprint foo.
* Committed a few of the outstanding approved patches into Linaro GCC-4.6
* Patch review week
* Caught up with email after vacation.
=== Plans ===
* Commit conditional compares patch.
* Commit the patch for LP838994.
* Investigate some of the performance issues with strlen and some of
the cases with - one of the ideas is to probably try and get the
specific testcases run under u-boot or as a bare-metal binary and look
at dumps of various performance monitoring counters and see what's
happening.
* Look at BRANCH_COST and finish that up next.
* Dust off patch for PR19599 . One of them them that has fallen into the cracks.
* Some patch review.
Meetings:
* 1-1s
* TCWG calls
* Thumb2 performance call.
Absences.
* 16th Oct (pm) - LLVM developer summit - London
* 31st Oct - 4th Nov - Linaro Summit Orlando - Travel booked - hotel
to be booked.
* 08 Nov - 11 Nov - Tentatively booked not approved.
* Dec 19 - 31st Dec - Tentatively booked not approved.
Merged both GCC 4.5 and 4.6 from FSF to Linaro. Matthias requested that
I avoid a particular upstream 4.6 commit, so I selected the revision
before that as the merge point. The problem was then fixes upstream, and
another fix was desirable, so I've redone the merge from the branch head.
Another widening-multiplies bug was reported to me (I logged it as
pr50318/lp843775), so I've fixed that and committed the fix upstream,
and filed a merge request on Launchpad.
Finished fixing the bugs in my thumb2 constants optimizations, and
backported the new patches to Linaro GCC 4.6. Pushed the updated stuff
to Launchpad for testing.
Richard Sandiford found a flaw in my patch for pr50193/lp836401, so I've
done another version of that and posted it upstream. Ramana didn't like
that version. I've started again trying to fix it a different way, but I
don't have it working just yet.
Continued work on my new constant reuse patch. I have it detecting many
constant expressions, and calculating the values for some of them. Once
it does that sufficiently well, the next step is to track what constants
are available where, I then I'll be in a position to find optimization
opportunities. At the moment, 'sufficiently well' could just mean
MOVW/MOVT pairs, as those are the most common
Tried to get the CS Panda Boards up and running again after the move. No
success. Ricardo is on the case. I'm still using the boards located at
Canonical.
Andrew
Continue looking at Richard's micro benchmarks taken from libav w.r.t
SMS and experiment with different patches that Richard wrote to
improve code generation.
Submitted SMS related patch for minor misc fixes
http://gcc.gnu.org/ml/gcc-patches/2011-09/msg00551.html
Trying to understand why to new version of the patch to support
instructions with
REG_INC_NOTE in SMS causes bootstrap failure. Will email to the ml regarding it.
(http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01216.html)
* Looked at LP bug 736661. Sent a patch upstream. Some positive feedback,
but it hasn't been approved or rejected yet.
* Looked at the old R_ARM_THM_CALL linker bug, after Matthias prepared
a self-contained testcase (thanks). Attached a patch to the bug.
Will submit upstream next week if testing goes OK.
* Looked at why the backport of lp823708-4.5 retriggered the same
bootstrap failure that Chung-Lin's patch did. Haven't been able
to reproduce yet.
* Looked at making the neon_vget_high/low patterns use ordinary
subreg moves. Found that this triggered a fair few latent bugs
in the rtl optimisers. Tried to fix those. This gave some nice
improvements in some of the libav loops.
* Added h264 loops to the libav microbenchmarks.
* Blueprints.
* Upstream patch review.
Richard
* Completed First-time wiki page, at least for now. Expecting to add more
information as I go.
* Running SPEC2K on the Snowball board. The tests are failing because I run
out out of memory. This is due to too little RAM available in the default
kernel configuration. (Official HW pack.) I had a go with creating a swap
file on the SD-card. The tests are then running, but results are slow (which
makes sense). Will try to make more memory available with changed
uboot-option, or with a fresh kernel.
* Discussing with Michael about benchmark candidates that will add a web
browsing perspective to the benchmarks we have. I suggest Sunspider and V8
benchmark suite for the JavaScript aspect, and EEMBC Browsing Bench and
perhaps ARMBBench for the load and render aspect. As for the imaging aspect
we have DENBench and ConsumerBench.
Best Regards
Åsa
== String routines ==
* Trying to understand my strlen behaviour that Michael identified
- Found lots of ways of making the faster case slower, but none of making
the slower case faster!
- Perf not being available on Panda (bug 702999/843628) made it
difficult to
dig down
* Fixing standards corner cases for strchr/memchr
- input match needs to be truncated to char (fixes bug 842258 & 791274)
* Tidying up formatting for cortex-strings release
* Looking at eglibc integration again
- getting confused by what has to happen in config.sub and how
other users of it
cope with triplets like armv7 even though it's not in config.sub
== QEMU ==
* Testing Peter's QEMU release
- All good
- Lost a few hours due to the broken version of l-i-f-ui in Oneiric
- PPA version works OK
* A little bit of perf profiling
== Other ==
* Managed to get hold of a nice fast build machine
== GDB ==
* Worked on hardware watchpoint support for gdbserver.
== GCC ==
* Analyzed root cause of three more ICEs when building Linux
kernel with mainline GCC (reported by Arnd):
PR target/50305: Inline asm reload failure when building Linux kernel
PR middle-end/50307: SSA checking ICE when building Linux kernel
PR tree-optimization/50318: ICE optimizing widening
multiply-and-accumulate
* Implemented proposed fix for PR target/50305 and posted for review.
== Misc ==
* Installed updated FPGA bitfiles on my Versatile Express and verified
that network stability issues (LP #673820) are now fixed.
* Booked Linaro Connect Q4.11 travel.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
RAG:
Red:
Amber:
Green: overrunning OMAP3 upstreaming work (mostly) replanned
Current Milestones:
|| || Planned || Estimate || Actual ||
||qemu-linaro 2011-09 || 2011-09-15 || 2011-09-15 || ||
Historical Milestones:
||qemu-linaro 2011-04 || 2011-04-21 || 2011-04-21 || 2011-04-21 ||
||qemu-linaro 2011-05 || 2011-05-19 || 2011-05-19 || n/a ||
||close out 1105 blueprints || 2011-05-28 || 2011-05-28 || 2011-05-19 ||
||complete 1111 planning || 2011-05-28 || 2011-05-28 || 2011-05-27 ||
||qemu-linaro-2011-06 || 2011-06-16 || 2011-06-16 || 2011-06-16 ||
||qemu-linaro-2011-07 || 2011-07-21 || 2011-07-21 || 2011-07-21 ||
||qemu-linaro 2011-08 || 2011-08-18 || 2011-08-18 || 2011-08-18 ||
== upstream-omap3-patches ==
* more reshuffling of patches and dropping of unnecessary changes (eg
code reformatting)
* we're going to divide this blueprint into four, each of which has a
reasonably clearly defined submilestone and an estimated 3
engineering weeks of work in it
* in order to not have work on this completely push out other items on
the schedule, we're going to limit work done on this to 2 or 3 days
each week
* still todo: actually split the blueprint, set dates for
submilestones, check that other blueprints fit reasonably in the
other half-week
== linaro-qemu-11.11 ==
* built a pre-release tarball and tested it -- looks good for next
week's release
* investigated whether we can reinstate the firmware blobs in our
releases (bringing us back into line with upstream) -- should be
possible but need to go through the license approval process since
some are GPLv3
== a15-system-mode-planning ==
* starting to see some (gentle) pressure for A15 support
* thinking about what we should do here; my current opinion is that
QEMU should implement an "A15 without virtualization or LPAE" -- we
have Linux kernels that will boot on this, and it is essentially
what an A15-on-A15 hw virt guest would see. The device work will be
needed for KVM anyway. Need to write this up.
== other ==
* submitted TSC licensing request to add the firmware blobs back into
our qemu-linaro tarballs, in line with how upstream do releases
* I need to track better how much time I'm spending on things like code
review on qemu-devel, minor bug fixing and other things that aren't
blueprints
* all holiday to the end of the year now booked (see below)
Current qemu patch status is tracked here:
https://wiki.linaro.org/PeterMaydell/QemuPatchStatus
Absences (to end of year):
Sep 19, Sep 29-Oct 07, Oct 17, Nov 21, Dec 15-Jan 03: leave
Oct 30-Nov 04: Linaro Connect Q4.11
Hi,
* I've been setting up a new system because the old laptop died
* finished the initial port of libunwind for Android on ARM
* changed debuggerd to make use of libunwind to unwind the stack of
crashing applications
* it works and the output looks great :)
* I plan to document these things in the wiki by next week
Regards
Ken
Just as an FYI, I've added these loops to the libav microbenchmarks
avg-h264-chroma-mc8-8.txt
avg-pixels8-8.txt
ff-h264-idct-add-8-8.txt
ff-put-pixels8x16-8.txt
h264-loop-filter-luma-8.txt
idct-internal-8.txt
put-h264-chroma-mc8-8.txt
put-h264-qpel8-h-lowpass-8.txt
put-h264-qpel8-hv-lowpass-8.txt
put-h264-qpel8-v-lowpass-8.txt
based on Michael's h264 profile. These loops:
decode_residual
ff_h264_decode_mb_cavlc
fill_decode_caches
aren't really the kind of thing that the microbenchmark is designed for;
running the whole h264 benchmark is probably a better test. Some of the
functions in the profile just consist of two copies of a simpler loop,
one after the other, so for those I just used the simpler loop.
Usual microbenchmark caveats apply.
Richard