Previously, because opt_aref and opt_aset don't push a frame, when they
would call rb_hash to determine the hash value of the key, the initial
level of recursion would incorrectly use the method id at the top of the
stack instead of "hash".
This commit replaces rb_exec_recursive_outer with
rb_exec_recursive_outer_mid, which takes an explicit method id, so that
we can make the hash calculation behave consistently.
rb_exec_recursive_outer was documented as being internal, so I believe
this should be okay to change.
df317151a5 removed the code to free
rb_hook_list_t, so repeated targeting of the same bmethod started
to leak the hook list. You can observe how the maximum memory use
scales with input size in the following script with `/usr/bin/time -v`.
```ruby
o = Object.new
o.define_singleton_method(:foo) {}
trace = TracePoint.new(:return) {}
bmethod = o.method(:foo)
ARGV.first.to_i.times { trace.enable(target:bmethod){} }
4.times {GC.start}
```
After this change the maximum doesn't grow as quickly.
To plug the leak, check whether the hook list is already allocated
when enabling the targeting TracePoint for the bmethod. This fix
also allows multiple TracePoints to target the same bmethod, similar
to other valid TracePoint targets.
Finally, free the rb_hook_list_t struct when freeing the method
definition it lives on. Freeing in the GC is a good way to avoid
lifetime problems similar to the one fixed in df31715.
[Bug #18031]
I originally added the check for
RubyVM::YJIT.trace_exit_locations_enabled? to fix errors when these
tests run without the stats feature enabled. However I forgot that this
will never be true when this test is booting, so nothing was running
when the stats feature is turned on.
Instead I've decided to make a new hash in the dump file and check if
exit locations are enabled there. If they aren't enabled we return early
to avoid checking for keys that won't exit in the dumped exit locations.
I chose to add this additional enabled check because empty exit
locations might not indicate that stats isn't enabled, it could mean the
feature is entirely broken. I do want these tests to fail if stats are
on and nothing was collected.
Followup to #5970
* Add missing space for `String#start_with?`.
* Add missing pluses for `String#tr` and
`Methods for Converting to New String` label.
* Move quote into the tag for `Whitespace in Strings` label.
When running with `--yjit-stats` turned on, yjit can inform the user
what the most common exits are. While this is useful information it
doesn't tell you the source location of the code that exited or what the
code that exited looks like. This change intends to fix that.
To use the feature, run yjit with the `--yjit-trace-exits` option,
which will record the backtrace for every exit that occurs. This functionality
requires the stats feature to be turned on. Calling `--yjit-trace-exits`
will automatically set the `--yjit-stats` option.
Users must call `RubyVM::YJIT.dump_exit_locations(filename)` which will
Marshal dump the contents of `RubyVM::YJIT.exit_locations` into a file
based on the passed filename.
*Example usage:*
Given the following script, we write to a file called
`concat_array.dump` the results of `RubyVM::YJIT.exit_locations`.
```ruby
def concat_array
["t", "r", *x = "u", "e"].join
end
1000.times do
concat_array
end
RubyVM::YJIT.dump_exit_locations("concat_array.dump")
```
When we run the file with this branch and the appropriate flags the
stacktrace will be recorded. Note Stackprof needs to be installed or you
need to point to the library directly.
```
./ruby --yjit --yjit-call-threshold=1 --yjit-trace-exits -I/Users/eileencodes/open_source/stackprof/lib test.rb
```
We can then read the dump file with Stackprof:
```
./ruby -I/Users/eileencodes/open_source/stackprof/lib/ /Users/eileencodes/open_source/stackprof/bin/stackprof --text concat_array.dump
```
Results will look similar to the following:
```
==================================
Mode: ()
Samples: 1817 (0.00% miss rate)
GC: 0 (0.00%)
==================================
TOTAL (pct) SAMPLES (pct) FRAME
1001 (55.1%) 1001 (55.1%) concatarray
335 (18.4%) 335 (18.4%) invokeblock
178 (9.8%) 178 (9.8%) send
140 (7.7%) 140 (7.7%) opt_getinlinecache
...etc...
```
Simply inspecting the `concatarray` method will give `SOURCE
UNAVAILABLE` because the source is insns.def.
```
./ruby -I/Users/eileencodes/open_source/stackprof/lib/ /Users/eileencodes/open_source/stackprof/bin/stackprof --text concat_array.dump --method concatarray
```
Result:
```
concatarray (nonexistent.def:1)
samples: 1001 self (55.1%) / 1001 total (55.1%)
callers:
1000 ( 99.9%) Object#concat_array
1 ( 0.1%) Gem.suffixes
callees (0 total):
code:
SOURCE UNAVAILABLE
```
However if we go deeper to the callee we can see the exact
source of the `concatarray` exit.
```
./ruby -I/Users/eileencodes/open_source/stackprof/lib/ /Users/eileencodes/open_source/stackprof/bin/stackprof --text concat_array.dump --method Object#concat_array
```
```
Object#concat_array (/Users/eileencodes/open_source/rust_ruby/test.rb:1)
samples: 0 self (0.0%) / 1000 total (55.0%)
callers:
1000 ( 100.0%) block in <main>
callees (1000 total):
1000 ( 100.0%) concatarray
code:
| 1 | def concat_array
1000 (55.0%) | 2 | ["t", "r", *x = "u", "e"].join
| 3 | end
```
The `--walk` option is recommended for this feature as it make it
easier to traverse the tree of exits.
*Goals of this feature:*
This feature is meant to give more information when working on YJIT.
The idea is that if we know what code is exiting we can decide what
areas to prioritize when fixing exits. In some cases this means adding
prioritizing avoiding certain exits in yjit. In more complex cases it
might mean changing the Ruby code to be more performant when run with
yjit. Ultimately the more information we have about what code is exiting
AND why, the better we can make yjit.
*Known limitations:*
* Due to tracing exits, running this on large codebases like Rails
can be quite slow.
* On complex methods it can still be difficult to pinpoint the exact cause of
an exit.
* Stackprof is a requirement to to view the backtrace information from
the dump file.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
`timeout 0.3.0` broke our test suite because we have some
tests that stubs `Process.clock_gettime` making it return
a value in the past, causing `Timeout` to trigger almost immediately.
I beleive it wasn't a problem before because it was relying on `Process.sleep`.
https://github.com/ruby/timeout/commit/e5911a303e
The chart (https://www.unicode.org/charts/case) that is currently
referred seems to be wrong.
Also, use the "latest" redirect and add titles of the section and table.
[Bug #18590]
We could fix it, but removing files in the directory recursively is
tedious in C and --mjit-debug is not a concern for users. We have
TestMJITDebug for detecting linker problems that are ignored by -O. It's
not really for maintaining --mjit-debug itself.
`RUBY_DEBUG_LOG_FILTER` specified only function names but this
patch also check file names for each log events.
If you specify `file:` or `func:` prefix, it's only filter
file names or func names (otherwize check both).
foo
# show log when file or func names are mached with foo
func:foo
# show log when func name matches foo
file:foo
# show log when file name matches foo
-file:foo,func:bar
# show log when file name does not contains foo
# and func name matches bar
Only growth heaps are allowed to start major GCs. Before this patch,
growth heaps are defined as size pools that freed more slots than had
empty slots (i.e. there were more dead objects that empty space).
But if the size pool is relatively stable and tightly packed with mostly
old objects and has allocatable pages, then it would be incorrectly
classified as a growth heap and trigger major GC. But since it's stable,
it would not use any of the allocatable pages and forever be classified
as a growth heap, causing major GC thrashing. This commit changes the
definition of growth heap to require that the size pool to have no
allocatable pages.
Having a while loop over `heap_prepare` makes the GC logic difficult to
understand (it is difficult to understand when and why `heap_prepare`
yields a free page). It is also a source of bugs and can cause an infinite
loop if `heap_page` never yields a free page.
`test_thread_instrumentation_fork_safe` has been failing occasionaly
on Ubuntu and Arch. At this stage we're not sure why, all we know is
that the child exit with status 1.
I suspect that something entirely unrelated cause the forked children
to fail on exit, so by using `exit!(0)` and doing assertions in the
parent I hope to be resilient to that.