[PATCH] D45546: [CachePruning] Clarify the per-directory entry limit on Linux ext4.

[Peter Collingbourne via Phabricator via llvm-commits]

pcc added inline comments.


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Comment at: include/llvm/Support/CachePruning.h:56
   /// diminishing returns on the effectiveness of the cache, and file
   /// systems have a limit on total number of files.
+  /// Notably ext4 on Linux, with the default setting (block
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MaskRay wrote:
> pcc wrote:
> > Update this bit.
> Change to what?
> 
> 
The second sentence does not follow from the first because the second is about files in a directory and the first is about total files. I might just say something like "some file systems have a limit on the total number of files, and some also limit the number of files per directory, such as ext4, which has a default limit of about 10M."


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Comment at: include/llvm/Support/CachePruning.h:57
   /// systems have a limit on total number of files.
+  /// Notably ext4 on Linux, with the default setting (block
+  /// size is 4096 and large_dir is off), there is a per-directory entry limit
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MaskRay wrote:
> pcc wrote:
> > My first instinct is not to add this much detail, but I guess it might dissuade the next person who comes along to try to "correct" this comment.
> Yeah I did not want to write the comment but you asked me to do so..
If you write something like the above, it should probably be enough.


Repository:
  rL LLVM

https://reviews.llvm.org/D45546