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[llvm-cov] Cache file status information

Authored by tunz on Mar 3 2021, 9:53 AM.

Description

[llvm-cov] Cache file status information

Currently, getSourceFile accesses file system to check if two paths are
the same file with a thread lock, which is a huge performance bottleneck
in some cases. Currently, it's accessing file system size(files) * size(files) times.

Thus, cache file status information, which reduces file system access to size(files) times.

When I tested it with two binaries and 16 cpu cores,
it saved over 70% of time.

Binary 1: 56 secs -> 3 secs
Binary 2: 17 hours -> 4 hours

Differential Revision: https://reviews.llvm.org/D97061

Details

Committed
vskMar 3 2021, 10:04 AM
Differential Revision
D97061: [llvm-cov] Cache file status information
Parents
rG9ee61cf3f67b: [XRay][x86_64] Fix CFI directives in assembly trampolines
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