Vedant Kumar c509534d2e [profile] Add a mode to continuously sync counter updates to a file ... Add support for continuously syncing profile counter updates to a file. The motivation for this is that programs do not always exit cleanly. On iOS, for example, programs are usually killed via a signal from the OS. Running atexit() handlers after catching a signal is unreliable, so some method for progressively writing out profile data is necessary. The approach taken here is to mmap() the `__llvm_prf_cnts` section onto a raw profile. To do this, the linker must page-align the counter and data sections, and the runtime must ensure that counters are mapped to a page-aligned offset within a raw profile. Continuous mode is (for the moment) incompatible with the online merging mode. This limitation is lifted in https://reviews.llvm.org/D69586. Continuous mode is also (for the moment) incompatible with value profiling, as I'm not sure whether there is interest in this and the implementation may be tricky. As I have not been able to test extensively on non-Darwin platforms, only Darwin support is included for the moment. However, continuous mode may "just work" without modification on Linux and some UNIX-likes. AIUI the default value for the GNU linker's `--section-alignment` flag is set to the page size on many systems. This appears to be true for LLD as well, as its `no_nmagic` option is on by default. Continuous mode will not "just work" on Fuchsia or Windows, as it's not possible to mmap() a section on these platforms. There is a proposal to add a layer of indirection to the profile instrumentation to support these platforms. rdar://54210980 Differential Revision: https://reviews.llvm.org/D68351		2019-10-31 16:04:09 -07:00
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Coverage	[Alignment][NFC] Move and type functions from MathExtras to Alignment	2019-10-14 13:14:34 +00:00
CMakeLists.txt	Revert "test commit"	2019-08-11 05:59:20 +00:00
GCOV.cpp	[llvm] Migrate llvm::make_unique to std::make_unique	2019-08-15 15:54:37 +00:00
InstrProf.cpp	[PGO] Fix typos from r359612. NFC.	2019-10-01 18:06:50 +00:00
InstrProfReader.cpp	[profile] Add a mode to continuously sync counter updates to a file	2019-10-31 16:04:09 -07:00
InstrProfWriter.cpp	[PGO] Fix typos from r359612. NFC.	2019-10-01 18:06:50 +00:00
LLVMBuild.txt	Update the file headers across all of the LLVM projects in the monorepo	2019-01-19 08:50:56 +00:00
ProfileSummaryBuilder.cpp	[llvm] Migrate llvm::make_unique to std::make_unique	2019-08-15 15:54:37 +00:00
SampleProf.cpp	[llvm-profdata] Minor format fix	2019-10-07 16:30:31 +00:00
SampleProfReader.cpp	[SampleFDO] Add profile remapping support for profile on-demand loading used	2019-10-18 22:35:20 +00:00
SampleProfWriter.cpp	[SampleFDO] Add indexing for function profiles so they can be loaded on demand	2019-10-09 21:36:03 +00:00