New submission from Stanisław Skonieczny (Uosiu) 
<stanislaw.skoniec...@gmail.com>:

We have an application that crawls filesystem using `os.scandir`. It uses 
multiple threads for various things. Application is used on variety of 
filesystems, some of them might be slow or occasionally unresponsive.

We have found out that sometimes whole crawling process is stuck and no thread 
makes any progress, even threads that are really simple, makes no IO and do not 
hold any locks. After running py-spy on process that was stuck we saw that one 
of the threads has entered `dentry.stat(follow_symlinks=False)` line and still 
holds the GIL. Other threads are stuck, because they are waiting for the GIL. 
This situation can take a long time.

I think that `DirEntry` should release GIL when stat cache is empty and syscall 
is performed.

This bug has already been fixed in `scandir` module. See: 
https://github.com/benhoyt/scandir/issues/131

----------
components: Library (Lib)
messages: 400337
nosy: Stanisław Skonieczny (Uosiu)
priority: normal
severity: normal
status: open
title: DirEntry.stat method should release GIL
type: behavior
versions: Python 3.10, Python 3.11, Python 3.6, Python 3.7, Python 3.8, Python 
3.9

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<https://bugs.python.org/issue45012>
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