9eb80ab3787e1851be8c686651688e870b93506b changed the method for stack
pointer restoration to fix segmentation faults. However, I made a
mistake in the patch and swapped a != for a ==, which caused an
arbitrary register (the first one specified) to get restored rather than
the stack pointer specifically. This patch fixes that issue and adds
test coverage to prevent regression.
This patch adds in validation at two different levels that address
annotations are page aligned. This is necessary as otherwise the mmap
calls will fail as MAP_FIXED/MAP_FIXED_NOREPLACE require page aligned
addresses. This happens silently in the subprocess. This patch adds
validation at snippet parsing time to give feedback to the user and also
adds asserts at code generation/address usage time to ensure that other
users of the Exegesis APIs conform to the same requirements.
This patch refactors the MMAP platform-specific preprocessor directives
in llvm-exegesis to a single file instead of having duplicate code split
across multiple files. These originally got introduced to get buildbots
green again due to platform specific failures.
```
[5323/5730] Building CXX object tools\llvm-exegesis\lib\CMakeFiles\LLVMExegesis.dir\Error.cpp.obj
In file included from C:\Work\david.spickett\llvm-project\llvm\tools\llvm-exegesis\lib\Error.cpp:9:
C:\Work\david.spickett\llvm-project\llvm\tools\llvm-exegesis\lib/Error.h(76,7): warning: private field 'SignalNumber' is not used [-Wunused-private-field]
76 | int SignalNumber;
| ^
```
`SignalNumber` was only being used on Unixes.
This patch switches to using explicit snippet crashes that contain more
information about the specific type of error (like the address for a
segmentation fault) that occurred. All these new error classes inherit
from SnippetExecutionFailure to allow for easily grabbing all of them in
addition to filtering for specific types using the standard LLVM error
primitives.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
…ndling.
Returns an error *and* a benchmark rather than an error *or* a
benchmark. This allows users to have custom error handling while still
being able to inspect the benchmark.
Apart from this small API change, this is an NFC.
This is an alternative to #74211.
Currently, the llvm-exegesis LatencyBenchmarkRunner repeats the
benchmark several times (currently 30) and then aggregates the result to
deal with noise in the measurement process. With this patch, the number
of repetitions to perform is made configurable rather than left as a
static number. This allows for significantly faster execution in
situations where someone is performing a task like experimenting with
memory annotations where the exact cycle counts might not be useful, and
also allows for increased precision when desired.
This reverts commit 30d700117b772d94d8474ec56bd6f9cc423fc613.
This relands commit 3ab41f912a6c219a93b87c257139822ea07c8863.
When I was updating the patch to use llvm::to_integer, I only ran the
lit tests and didn't run the unit tests, one of which started to fail.
This patch fixes the broken unit test.
Core dumps are currently enabled within the llvm-exegesis subprocess
executor. This can create a lot of core dumps when going through
different snippets that might segfault when experimenting with memory
annotations. These core dumps are not really needed as the information
about the segfault is reported directly to the user.
This reverts commit 52b4b357268ac114f7972e37da1e5954f322df09.
This commit was causing build failures on bots without libpfm installed
as the CHECK requires were not set correctly. The test added should only
run on machines with libpfm enabled due to the limitations currently
imposed by the subprocess execution mode.
This reverts commit 9eb80ab3787e1851be8c686651688e870b93506b.
This is causing failures on multiple builders. Pulling it out until I
have time to fix it.
Before this patch, in subprocess mode, llvm-exegesis setup the stack
pointer register with the rest of the registers when it was requested by
the user. This would cause a segfault when the instructions to start the
perf counter ran as they use the stack to preserve the three registers
needed to make the syscall. This patch moves the setup of the stack
register to after the configuration of the perf counter to fix this
issue so that we have a valid stack pointer for all the preceeding
operations.
Regression test added.
This fixes#72193.
This reverts commit ea5de6021cf69a233106689cc6f0ee14899e1a83.
This patch was reverted as it broke a test on x86_64 Darwin due to the
symbol naming being different between platforms. As Darwin isn't a
supported platform for executing snippets for llvm-exegesis, we can just
disable the test to fix the issue.
This broke
tools/llvm-exegesis/X86/latency/dummy-counters.test
on Mac, see comment on the PR.
> There was an issue with certain configurations failing to build due to a
> deleted Error constructor that should be fixed with this relanding.
This reverts commit 92b821f2dcddbfa934689e10d8f11df150ab1043.
This reverts commit ddc6ef46418cc419041d0bd85de40d0eb9396848.
This relands commit 12b0ab2c9ce8ef813d9eb888860f20daac3336bd.
There was an issue with certain configurations failing to build due to a
deleted Error constructor that should be fixed with this relanding.
This reverts commit 12b0ab2c9ce8ef813d9eb888860f20daac3336bd.
Currently failing on certain configurations due to a missing
constructor. Pulling out so that I can reproduce the issue and make sure
I fix it before resubmitting.
This patch refactors ExecutableFunction to use a named constructor
pattern, namely adding the create function, so that errors occurring
during the creation of an ExecutableFunction can be propogated back up
rather than having to deal with them in report_fatal_error.
Currently, when making the ioctl system call, we're not preserving rcx
and r11. The system call will clobber these registers, meaning that the
values of the registers in the snippet will be different than expected.
This patch fixes that be preserving the registers around the system
call, similar to how the other registers involved in the making the
system call get preserved.
Fixes#72741.
If there were some scheduler effects where something like the parent
process got interrupted while the child process continued to run, there
would be nothing blocking it from exiting before the parent process
issued a PTRACE_ATTACH call. This would cause transient failures as this
occurred pretty rarely. This patch removes the possibility of a
transient failure by ensuring that the parent process attaches to the
child process before sending the counter file descriptor through the
socket, ensuring that the child process has at most progressed to being
blocked in the read call for the counter file descriptor.
This reverts commit 186db1bcb0096a6af348d7e17866c68fa2004068.
This relands commit 0718c1a8405ac130d72cd3525befed2911618cc7.
The REQUIRES flag in the test that was added only specified that the
machine needed to have the capability to execute the snippet rather than
actually run it with performance counters. This would work with
--dummy-perf-counters, but that is not currently supported in the
subprocess execution mode. So for now, we require the ability to
actually perform measurements to prevent test failures in configurations
that don't have libpfm or access to performance counters.
This reverts commit 0718c1a8405ac130d72cd3525befed2911618cc7.
The test doesn't have the correct requires string apparently because it
attempts to run on all the buildbots. Reverting until I have time to fix
the test and reland it.
I made a typo at some point while doing the subprocess implementation,
trying to pop RIP from the stack. For whatever reason, this ends up as
popq %rax after being JITed, which means we aren't properly preserving
the value of %rdi.
Regression test added.
This fixes#72188.
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
This will make it easy for callers to see issues with and fix up calls
to createTargetMachine after a future change to the params of
TargetMachine.
This matches other nearby enums.
For downstream users, this should be a fairly straightforward
replacement,
e.g. s/CodeGenOpt::Aggressive/CodeGenOptLevel::Aggressive
or s/CGFT_/CodeGenFileType::
There are still some transient failures on the clang-avx512 builder on
the new subprocess memory tests. Some of them seem to be related to an
inability to fork, but it's hard to debug currently as there is no
explicit error handling for a failed fork call, and nice error reporting
for a failed fork is something that we should have regardless.
Some error logging in llvm-exegesis under the subprocess executor just
prints a generic failure information rather than any details about the
error as we omit printing the string version of errno. This patch adds
in printing errno at all relevant points in the subprocess executor that
were previously missed.
Reviewed By: courbet
Differential Revision: https://reviews.llvm.org/D157682
When using the subprocess execution mode and dummy perf counters
currently, cryptic errors will be printed out related to not being able
to send the file descriptor through a socket. This patch prints out an
explicit message that this configuration isn't (currently) supported.
Reviewed By: courbet
Differential Revision: https://reviews.llvm.org/D157686
Some 32-bit architectures don't have mmap and define mmap2 instead.
E.g. on riscv32 we may get
```
| /mnt/b/yoe/master/build/tmp/work-shared/llvm-project-source-17.0.0-r0/git/llvm/tools/llvm-exegesis/lib/X86/Target.cpp:1116:19: error: use of undeclared identifier 'SYS_mmap'
| 1116 | generateSyscall(SYS_mmap, MmapCode);
| | ^
| /mnt/b/yoe/master/build/tmp/work-shared/llvm-project-source-17.0.0-r0/git/llvm/tools/llvm-exegesis/lib/X86/Target.cpp:1134:19: error: use of undeclared identifier 'SYS_mmap'
| 1134 | generateSyscall(SYS_mmap, GeneratedCode); | | ^
| 1 warning and 2 errors generated.
```
Co-Authored-By: Fangrui Song <i@maskray.me>
Differential Revision: https://reviews.llvm.org/D158375
On some targets, not all types of instruction operands are currently
handled. Instead of stopping the whole llvm-exegesis run because of any
instruction opcode that is not fully supported, write a per-opcode error
message and proceed to other opcodes. This improves the reliability of
--opcode-index=-1 sweep on partially supported targets.
Depends on: D146302, D146303
~~
Huawei RRI, OS Lab
Reviewed By: courbet
Differential Revision: https://reviews.llvm.org/D146304
D150312 added a TODO:
TODO: consider renaming the field `StartAtCycle` and `Cycles` to
`AcquireAtCycle` and `ReleaseAtCycle` respectively, to stress the
fact that resource allocation is now represented as an interval,
relatively to the issue cycle of the instruction.
This patch implements that TODO. This naming clarifies how to use these
fields in the scheduler. In addition it was confusing that `StartAtCycle` was
singular but `Cycles` was plural. This renaming fixes this inconsistency.
This commit as previously reverted since it missed renaming that came
down after rebasing. This version of the commit fixes those problems.
Differential Revision: https://reviews.llvm.org/D158568
D150312 added a TODO:
TODO: consider renaming the field `StartAtCycle` and `Cycles` to
`AcquireAtCycle` and `ReleaseAtCycle` respectively, to stress the
fact that resource allocation is now represented as an interval,
relatively to the issue cycle of the instruction.
This patch implements that TODO. This naming clarifies how to use these
fields in the scheduler. In addition it was confusing that `StartAtCycle` was
singular but `Cycles` was plural. This renaming fixes this inconsistency.
This commit as previously reverted since it missed renaming that came
down after rebasing. This version of the commit fixes those problems.
Differential Revision: https://reviews.llvm.org/D158568
D150312 added a TODO:
TODO: consider renaming the field `StartAtCycle` and `Cycles` to
`AcquireAtCycle` and `ReleaseAtCycle` respectively, to stress the
fact that resource allocation is now represented as an interval,
relatively to the issue cycle of the instruction.
This patch implements that TODO. This naming clarifies how to use these
fields in the scheduler. In addition it was confusing that `StartAtCycle` was
singular but `Cycles` was plural. This renaming fixes this inconsistency.
Differential Revision: https://reviews.llvm.org/D158568
Currently BenchmarkRunner.cpp stores the return code of recvmsg as
size_t. Not only is this incorrect (as recvmsg returns ssize_t), but it
also makes the error code check after the statement completely irrelvant
as it checks if the number of bytes read is greater than zero (which
will always be true for an unsigned type).
When compiling against recent glibc (>= 2.35) but old kernel headers (< 4.18), `SYS_rseq` is not defined and thus llvm-exegesis fails to build. So also check that `SYS_rseq` is defined before trying to use it.
Fixes https://github.com/llvm/llvm-project/issues/64456
Reviewed By: MaskRay, gchatelet
Differential Revision: https://reviews.llvm.org/D157189
