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| author | Vedant Kumar <vsk@apple.com> | 2019-11-12 10:24:23 -0800 |
|---|---|---|
| committer | Vedant Kumar <vsk@apple.com> | 2019-11-18 12:56:58 -0800 |
| commit | 2492b5a12550f7c4bb428c3761392f2ce47fa269 (patch) | |
| tree | d652ab622dad665ad46a59d822c3bcc61003c3f9 /clang/docs/SourceBasedCodeCoverage.rst | |
| parent | cc1b0bc24d2703087d80e4f4dc0560879733299a (diff) | |
| download | bcm5719-llvm-2492b5a12550f7c4bb428c3761392f2ce47fa269.tar.gz bcm5719-llvm-2492b5a12550f7c4bb428c3761392f2ce47fa269.zip | |
[profile] Support online merging with continuous sync mode
Make it possible to use online profile merging ("%m" mode) with
continuous sync ("%c" mode).
To implement this, the merged profile is locked in the runtime
initialization step and either a) filled out for the first time or b)
checked for compatibility. Then, the profile can simply be mmap()'d with
MAP_SHARED set. With the mmap() in place, counter updates from every
process which uses an image are mapped onto the same set of physical
pages assigned by the filesystem cache. After the mmap() is set up, the
profile is unlocked.
Differential Revision: https://reviews.llvm.org/D69586
Diffstat (limited to 'clang/docs/SourceBasedCodeCoverage.rst')
| -rw-r--r-- | clang/docs/SourceBasedCodeCoverage.rst | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/clang/docs/SourceBasedCodeCoverage.rst b/clang/docs/SourceBasedCodeCoverage.rst index 0beb284e475..73197a57713 100644 --- a/clang/docs/SourceBasedCodeCoverage.rst +++ b/clang/docs/SourceBasedCodeCoverage.rst @@ -90,12 +90,11 @@ directory structure will be created. Additionally, the following special * "%c" expands out to nothing, but enables a mode in which profile counter updates are continuously synced to a file. This means that if the instrumented program crashes, or is killed by a signal, perfect coverage - information can still be recovered. Continuous mode is not yet compatible with - the "%Nm" merging mode described above, does not support value profiling for - PGO, and is only supported on Darwin. Support for Linux may be mostly - complete but requires testing, and support for Fuchsia/Windows may require - more extensive changes: please get involved if you are interested in porting - this feature. + information can still be recovered. Continuous mode does not support value + profiling for PGO, and is only supported on Darwin at the moment. Support for + Linux may be mostly complete but requires testing, and support for + Fuchsia/Windows may require more extensive changes: please get involved if + you are interested in porting this feature. .. code-block:: console |
