Summary:
We found a nondeterministic behavior when doing online profile merging
for multi-process applications. The application forks a sub-process and
sub-process sets to get SIGKILL when the parent process exits,
The first process gets the lock, and dumps the profile. The second one
will mmap the file, do the merge and write out the file. Note that before
the merged write, we truncate the profile.
Depending on the timing, the child process might be terminated
abnormally when the parent exits first. If this happens:
(1) before the truncation, we will get the profile for the main process
(2) after the truncation, and before write-out the profile, we will get
0 size profile.
(3) after the merged write, we get merged profile.
This patch temporarily suspend the SIGKILL for PR_SET_PDEATHSIG
before profile-write and restore it after the write.
This patch only applies to Linux system.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: xur, llvm-commits
Differential Revision: https://reviews.llvm.org/D29954
llvm-svn: 295364
This makes __llvm_profile_set_filename() work across dylib boundaries on
Darwin.
This functionality was originally meant to work on all platforms, but
was moved to a Linux-only directory with r272404. The root cause of the
test failure on Darwin was that lprofCurFilename was not marked weak.
Each dylib maintained its own copy of the variable due to the two-level
namespace.
Tested with check-profile (on Darwin). I don't expect this to regress
other platforms.
Differential Revision: https://reviews.llvm.org/D25707
llvm-svn: 284440
Profile-aarch64 :: Linux/comdat_rename.test
Profile-aarch64 :: Linux/extern_template.test
Profile-aarch64 :: Linux/instrprof-comdat.test
Profile-aarch64 :: Linux/instrprof-cs.c
The issue is that the created (aarch64) binaries were attempting to run natively
instead of running through %run, which guarantees running in the proper
environment if the compilation was configured correctly.
llvm-svn: 282264
Commit r280364 has introduced some call-graph optmisations making a profiler
test "fail" due to not expecting the compiler to be "smart", and fold constants
across functions. This commit works around the issue, leaving the origial
semantics intact.
llvm-svn: 280365
(Part-1 merging API is in profile runtime)
This patch implements a portable file opening API
with exclusive access for the process. In-process
profile merge requires profile file update to be
atomic/fully sychronized.
llvm-svn: 271864
The original submittion triggered a BFD linker bug (2.24) on Aarch64 only. Before
the build bot is upgraded to more recent linker, restrict the test to be
executed only with gold linker.
llvm-svn: 258437
(second try with more strict config check)
Currently, only gc-sections related tests are added. Gold
linker currently is required due to PR19161 of bfd linker.
llvm-svn: 257456
