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| author | Peter Collingbourne <peter@pcc.me.uk> | 2017-06-23 16:56:27 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2017-06-23 16:56:27 +0000 |
| commit | 24989b18385b3b168ef7dcc866f3edc239ccae7f (patch) | |
| tree | d954a916a7ff8c86c1c00382bc4916a9f9dd3fea /docs | |
| parent | e69da60ae245599a8e5bc89e4b0d237d084d944a (diff) | |
docs: Add documentation for the ThinLTO cache pruning policy string.
Differential Revision: https://reviews.llvm.org/D34546
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306125 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ThinLTO.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/docs/ThinLTO.rst b/docs/ThinLTO.rst index d417febda5..71a23380ef 100644 --- a/docs/ThinLTO.rst +++ b/docs/ThinLTO.rst @@ -126,6 +126,38 @@ which currently must be enabled through a linker option. - lld (as of LLVM r296702): ``-Wl,--thinlto-cache-dir=/path/to/cache`` +Cache Pruning +------------- + +To help keep the size of the cache under control, ThinLTO supports cache +pruning. Cache pruning is supported with ld64 and ELF lld, but currently only +ELF lld allows you to control the policy with a policy string. The cache +policy must be specified with a linker option. + +- ELF lld (as of LLVM r298036): + ``-Wl,--thinlto-cache-policy,POLICY`` + +A policy string is a series of key-value pairs separated by ``:`` characters. +Possible key-value pairs are: + +- ``cache_size=X%``: The maximum size for the cache directory is ``X`` percent + of the available space on the the disk. Set to 100 to indicate no limit, + 50 to indicate that the cache size will not be left over half the available + disk space. A value over 100 is invalid. A value of 0 disables the percentage + size-based pruning. The default is 75%. + +- ``prune_after=Xs``, ``prune_after=Xm``, ``prune_after=Xh``: Sets the + expiration time for cache files to ``X`` seconds (or minutes, hours + respectively). When a file hasn't been accessed for ``prune_after`` seconds, + it is removed from the cache. A value of 0 disables the expiration-based + pruning. The default is 1 week. + +- ``prune_interval=Xs``, ``prune_interval=Xm``, ``prune_interval=Xh``: + Sets the pruning interval to ``X`` seconds (or minutes, hours + respectively). This is intended to be used to avoid scanning the directory + too often. It does not impact the decision of which files to prune. A + value of 0 forces the scan to occur. The default is every 20 minutes. + Clang Bootstrap --------------- |