To perform a regular method call, the VM needs two structs,
`rb_call_info` and `rb_call_cache`. At the moment, we allocate these two
structures in separate buffers. In the worst case, the CPU needs to read
4 cache lines to complete a method call. Putting the two structures
together reduces the maximum number of cache line reads to 2.
Combining the structures also saves 8 bytes per call site as the current
layout uses separate two pointers for the call info and the call cache.
This saves about 2 MiB on Discourse.
This change improves the Optcarrot benchmark at least 3%. For more
details, see attached bugs.ruby-lang.org ticket.
Complications:
- A new instruction attribute `comptime_sp_inc` is introduced to
calculate SP increase at compile time without using call caches. At
compile time, a `TS_CALLDATA` operand points to a call info struct, but
at runtime, the same operand points to a call data struct. Instruction
that explicitly define `sp_inc` also need to define `comptime_sp_inc`.
- MJIT code for copying call cache becomes slightly more complicated.
- This changes the bytecode format, which might break existing tools.
[Misc #16258]
Now I'm not exactly sure why I needed to check `stop_worker_p` after
`mjit_copy_cache_from_main_thread` of `convert_unit_to_func`
in 4161674b2f.
If it's for avoiding deadlock under `in_gc` condition, we should keep it.
However, if it's not the case and it's just for retrying accidental
compilation failure or just to avoid `MJIT_ATOMIC_SET` and
`compact_all_jit_code`, I think this quick stop path is not mandatory.
Because this path is somewhat problematic in my upcoming fix in
mjit_worker, let me try to remove this first and see how CI goes.
for all compilations and compaction.
Prior to this commit, the last-compiled code has not been used because
MJIT worker is stopped before setting the code, and compaction has also
been skipped.
But it was not intentional and `wait: true` pause should wait until
those two things by its feature.
Tabs are expanded because previously the file did not have any tab indentation.
Please update your editor config, and use misc/expand_tabs.rb in the pre-commit hook.
At least since 2004, glibc's <string.h> annotates memcpy as
__attribute__((__nonnull__)). This basedir is passed to it. When
LOAD_RELATIVE is not defined and MJIT_SEARCH_BUILD_DIR is not set,
this variable is never updated. Should initialize with meaningful
default value.
This reverts commit b79899b56a.
I wanted to test r67638 first. Now let me try this as well.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67639 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This reverts commit 4bd4d4e4cf.
Sorry, let me test another one first
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67637 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This is a possible bug from recent "JIT recompile" introduction.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67631 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ISeq can move, so we need to tell MJIT where the new location is.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67624 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
I assumed that ISeq is never GC-ed by `in_jit` + `mjit_mark` on copy job
ISeq, but unfortunately I found SEGV on `mjit_copy_job_handler` in which
iseq->body was somehow Qnil. And it seems to be fixed by disabling the
job when `mjit_free_iseq` is called for the ISeq.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67551 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
as debugged in PR
[close https://github.com/ruby/ruby/pull/2130]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67549 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This reverts commit a1b5d20068.
Revert "Revert "Skip recompiling tests on i686 Linux""
This reverts commit 7b88a9207b.
Revert "Simplify matrix for debugging"
This reverts commit e85d6c5c5e.
Sorry, these 3 commits were under debugging in
https://github.com/ruby/ruby/pull/2129 but accidentally merged by using
`git svn dcommit` instead of `git push` to the topic branch 🙇
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67538 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
I'm writing `//` comments in newer MJIT code after C99 enablement
(because I write 1-line comments more often than multi-line comments
and `//` requires fewer chars on 1-line) and then they are mixed
with `/* */` now.
For consistency and to avoid the conversion in future changes, let me
finish the rewrite in MJIT-related code.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67533 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
It seems that `debug_counter_show_results_at_exit` could be called
earlier than `mjit_finish` sometimes.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67380 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
and guard iseq from GC by marking iseq in mjit_copy_job.
This is a refactoring for implementing inlining later and
should not be fixing or introducing any bugs.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67286 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* --jit-min-calls: 5 -> 10000
--jit-min-calls=5 obviously can compile non hotspot. This was not a
problem for MJIT-benchmarks and Optcarrot because the former has very
few hot optimiziable methods and the latter is likely to trigger
compilation of hotspot by its intensive calls to optimizable hotspot
methods and has a very short window to allow limited compilations.
In real-world applications, it has more time to compile more methods and
it pressures computer's limited resources like icache. We should avoid
compiling too many methods. Also compiling many methods exhausts time
budget for compilation in one ruby process lifetime and delays the "JIT
compaction" of Ruby 2.6.
JVM is known to use 1,500 for C1 (client) compiler and 10,000 for C2
(server) compiler for -XX:CompileThreshold by default.
https://docs.oracle.com/javase/8/embedded/develop-apps-platforms/codecache.htm
When things are called X,000 times, requiring 10,000 can eliminate
compilation of methods which are called only once in these X,000
iterations and obviously not hotspot. And in fact things like
unicorn-worker-killer restarts unicorn process every 4096 requests.
So I felt 10,000 is good for such an environment.
* --jit-max-cache: 1000 -> 100
By the same reason stated above, we should not allow compiling many
methods especially on MJIT which has a larger overhead due to poor code
locality by dlopen and whose code is also likely to be bigger by just
inlining many VM instructions with -O3 rather than directly generating
low-level code.
In JVM -XX:ReservedCodeCacheSize is 32M for reserved and 48M for maximum.
--jit-max-cache=1,000 could be closer to it, but in this case MJIT's
compilation is slow due to data synchronization between threads (to be
improved in Ruby 2.7 though) and we do not want to delay the "JIT
compaction" for a long time.
So I chose a really conservative number for this, but by having method
inlining in the future, wider range could be optimized even with this
value.
* Optcarrot
--disable-gems, --benchmark Lan_Master.nes 12 attempts.
No significant impact.
| r67276 | r67276 --jit | after --jit |
|:-------------------|:------------------|:------------------|
| 50.44369263063978 | 72.87390680773056 | 73.47873485047297 |
| 50.58788746124193 | 78.06820808947026 | 78.29723420171945 |
| 50.77509250801378 | 80.29010348842613 | 78.94689404460769 |
| 50.935361702064405 | 80.42796829926374 | 80.39539527351525 |
| 51.27352672981195 | 81.98758158033202 | 81.6754198664817 |
| 51.720715743242124 | 82.00118535811626 | 82.22960569251283 |
| 51.89643169822524 | 82.2290091613556 | 82.5013636146388 |
| 51.95895898113868 | 82.37318990939565 | 82.74002377794454 |
| 52.10124886807968 | 82.48796686037502 | 83.23354941183932 |
| 52.292280637519376 | 83.0265226541066 | 84.01552618012572 |
| 52.51856237784144 | 83.8797360318052 | 84.8588319093393 |
| 52.65076845986818 | 84.80037351256634 | 85.13577756273656 |
* Railsbench
`WARMUP=20000 BENCHMARK=1000 bin/bench` of https://github.com/k0kubun/railsbench.
It gets closer to --disable=jit.
| | r67276 | r67276 | after |
| | | --jit | --jit |
|:----------|:-------|:-------|:-------|
| req/s | 891.3 | 742.2 | 841.5 |
|:----------|:-------|:-------|:-------|
| 50%ile ms | 1.00 | 1.21 | 1.08 |
| 66%ile ms | 1.02 | 1.24 | 1.09 |
| 75%ile ms | 1.03 | 1.28 | 1.10 |
| 80%ile ms | 1.03 | 1.30 | 1.11 |
| 90%ile ms | 1.09 | 1.42 | 1.15 |
| 95%ile ms | 1.32 | 1.65 | 1.27 |
| 98%ile ms | 4.79 | 2.23 | 1.81 |
| 99%ile ms | 5.68 | 7.52 | 6.64 |
|100%ile ms | 6.52 | 9.69 | 8.59 |
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67277 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
and functions to clarify the intention and make sure it's not used in a
surprising way (like using 2, 3, ... other than 0, 1 even while it seems
to be a boolean).
This is a retry of r66775. It included some typos...
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66778 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This reverts commit bb1a1aeab0.
We hit something on ci.rvm.jp, reverting until investigation is done.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66776 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
and functions to clarify the intention and make sure it's not used in a
surprising way (like using 2, 3, ... other than 0, 1 even while it seems
to be a boolean).
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66775 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
get_uniq_filename never returns NULL but raises an exception on
failure.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66292 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Give the whole MJIT header path name by preloaded shared library
mjit_build_dir.so, than building the path from a given directory
name and the embedded base name.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66280 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
It is not needed since we have LIST_HEAD_INIT initializer in
mjit_worker.c
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66203 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
in a new variable cc_common_args.
`cflags=-save-temps=obj` makes MJIT fail like:
https://rubyci.org/logs/www.rubyist.net/~akr/chkbuild/debian/ruby-trunk/log/20181203T095000Z.log.html.gz
This rubyci specifies -save-temps=obj in CFLAGS to use update-deps, and
the flag is harmful when we want to use -pipe flag.
mjit_worker.c: prefer cc_common_args over CC_COMMON_ARGS
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66164 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
because we mostly use cc_path now and the comment is obsolete (CC_PATH
is now absolute path and the TODO is already resolved).
mjit.c: use CC_COMMON_ARGS[0] directly
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66162 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
postponed_job is safe to use in signal handlers, but is not
thread-safe for MJIT. Implement a workqueue for MJIT
thread-safety.
[Bug #15316]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66100 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-local variable to global variable.
Consider this case:
1. MJIT worker: dequeue ISeq (stop_worker_p was still FALSE)
2. Ruby thread: call Kernel#exec, which calls mjit_finish(FALSE),
sets `stop_worker_p = TRUE`, and fires RUBY_VM_CHECK_INTS() once
3. MJIT worker: register copy job, but found stop_worker_p is TRUE.
set `worker_stopped = TRUE` and the thread stops.
4. Function-local job variable expires by the thread stop (this is eliminated by this commit)
5. Ruby thread: find `worker_stopped` becamse TRUE, start Kernel#exec.
Kernel#exec fails but exception is rescued.
6. Ruby thread: call RUBY_VM_CHECK_INTS. copy job is dispatched but job variable
is already expired.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66035 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
because JIT-ed code may still be on stack at this time, unlike
in ruby_cleanup().
This hopes to fix: (take 2)
http://ci.rvm.jp/results/trunk-mjit-wait@silicon-docker/1480207
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65999 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
http://ci.rvm.jp/results/trunk-mjit-wait@silicon-docker/1480173
It tries to print C backtrace but fails. And core file on the server
seems to be stopping on the irrelevant place due to its own signal
handler for the dump.
And I failed to reproduce this SEGV on my machine.
I don't know why it's broken, so let me try this change to investigate
the reason of SEGV.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65997 b2dd03c8-39d4-4d8f-98ff-823fe69b080e