OpenBSD RubyCI has failed with SEGV since 4bcd5981e8.
20200312T223005Z.fail.html.gz
This was because `status->cc_entries` could be stale after `realloc` call
for inlined iseqs.
Fixing 4bcd5981e8/mjit.c (L338)
should be the right solution for this. We may not be able to free the cc immediately.
Plus, we're not copying cc but just holding references to be marked. cc
should be GC-ed once jit_unit is freed.
jit_unit to avoid marking wrong cc entries when inlined iseq is compiled
multiple times, resolving the TODO added by daf7c48d88.
This obviates pseudo jit_unit in inlined iseq introduced by 7ec2359374
and fixes memory leak of the adhoc unit.
This patch contains several ideas:
(1) Disposable inline method cache (IMC) for race-free inline method cache
* Making call-cache (CC) as a RVALUE (GC target object) and allocate new
CC on cache miss.
* This technique allows race-free access from parallel processing
elements like RCU.
(2) Introduce per-Class method cache (pCMC)
* Instead of fixed-size global method cache (GMC), pCMC allows flexible
cache size.
* Caching CCs reduces CC allocation and allow sharing CC's fast-path
between same call-info (CI) call-sites.
(3) Invalidate an inline method cache by invalidating corresponding method
entries (MEs)
* Instead of using class serials, we set "invalidated" flag for method
entry itself to represent cache invalidation.
* Compare with using class serials, the impact of method modification
(add/overwrite/delete) is small.
* Updating class serials invalidate all method caches of the class and
sub-classes.
* Proposed approach only invalidate the method cache of only one ME.
See [Feature #16614] for more details.
Now, rb_call_info contains how to call the method with tuple of
(mid, orig_argc, flags, kwarg). Most of cases, kwarg == NULL and
mid+argc+flags only requires 64bits. So this patch packed
rb_call_info to VALUE (1 word) on such cases. If we can not
represent it in VALUE, then use imemo_callinfo which contains
conventional callinfo (rb_callinfo, renamed from rb_call_info).
iseq->body->ci_kw_size is removed because all of callinfo is VALUE
size (packed ci or a pointer to imemo_callinfo).
To access ci information, we need to use these functions:
vm_ci_mid(ci), _flag(ci), _argc(ci), _kwarg(ci).
struct rb_call_info_kw_arg is renamed to rb_callinfo_kwarg.
rb_funcallv_with_cc() and rb_method_basic_definition_p_with_cc()
is temporary removed because cd->ci should be marked.
This commit introduces an "inline ivar cache" struct. The reason we
need this is so compaction can differentiate from an ivar cache and a
regular inline cache. Regular inline caches contain references to
`VALUE` and ivar caches just contain references to the ivar index. With
this new struct we can easily update references for inline caches (but
not inline var caches as they just contain an int)
Fixes [Bug #16332]
Constant access was changed to no longer allow top-level constant access
through `nil`, but `defined?` wasn't changed at the same time to stay
consistent.
Use a separate defined type to distinguish between a constant
referenced from the current lexical scope and one referenced from
another namespace.
Prior to this changeset, majority of inline cache mishits resulted
into the same method entry when rb_callable_method_entry() resolves
a method search. Let's not call the function at the first place on
such situations.
In doing so we extend the struct rb_call_cache from 44 bytes (in
case of 64 bit machine) to 64 bytes, and fill the gap with
secondary class serial(s). Call cache's class serials now behavies
as a LRU cache.
Calculating -------------------------------------
ours 2.7 2.6
vm2_poly_same_method 2.339M 1.744M 1.369M i/s - 6.000M times in 2.565086s 3.441329s 4.381386s
Comparison:
vm2_poly_same_method
ours: 2339103.0 i/s
2.7: 1743512.3 i/s - 1.34x slower
2.6: 1369429.8 i/s - 1.71x slower
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]
setlocal relies on cfp->ep, and frame-omitted method inlining introduced
in Ruby 2.7 kept it wrong.
This change might slow down frame-omitted method inlining for cfp->ep
manipulation, and it obviously complicates the implementaion more. By
introducing an optimization that changes Ruby's local variable to C
local variable, we could optimize it and simplify the cfp->ep
manipulation later.
[Bug #15971]
for ISeq including only leaf and no-handles_sp insns except leaf.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67574 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
for opt_aref with inline cache to minimize the possibility of JIT cancel.
Also opt_aset and opt_mod are added for the targets.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67547 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
cfp->bp was (re-)introduced by Kokubun san, but VM doesn't use it
because I (ko1) want to remove it in a future. But using it make
leave instruction fast because of sp consisntency check.
So now VM uses cfp->bp.
To use cfp->bp, I checked the value and I found that it is not a
"initial value of sp" but a "initial value of ep". Fix this problem
and fix all bp references (this is why bp is renamed to bp_).
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67342 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
to avoid inlining a method call when it becomes argument_arity_error,
fixing a potential bug.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67330 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
If a function has rb_warning() that is not a leaf because warning
ultimately is a method call of Warning#warn.
If a function has rb_name_error() that is not a leaf because
NameError is allocated, then initialized. This of course
involves calling NameError#initialize.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66976 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Now that comma at the end of enum is allowed, we can write this much
more straight-forward.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66960 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Also previous rb_vm_insn_len_info is now a function static variable.
It seems nobody else is using it.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66958 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
C99 allows string literals of at least 4095 characters (cf: ISO/IEC
9899:1999 section 5.2.4.1) so the previous complex struct layout is no
longer necessary. Just dump the verbatim memory contents we want.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66957 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This changeset modifies the VM generator so that vm.inc is written in
C99. Also added some comments in _insn_entry.erb so that the
intention of each parts to be made more clear. I think this improves
overall readability of the generated VM.
Confirmed that the exact same binary is generated before/after this
changeset.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66923 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
