Merge branch 'access-creds'

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The access() (and faccessat()) credentials change can cause an
unnecessary load on the RCU machinery because every access() call ends
up freeing the temporary access credential using RCU.

This isn't really noticeable on small machines, but if you have hundreds
of cores you can cause huge slowdowns due to RCU storms.

It's easy to avoid: the temporary access crededntials aren't actually
normally accessed using RCU at all, so we can avoid the whole issue by
just marking them as such.

* access-creds:
  access: avoid the RCU grace period for the temporary subjective credentials

...

This commit is contained in:

Linus Torvalds 2019-07-25 08:36:29 -07:00

parent bed38c3e2d d7852fbd0f

commit a29a0a467e

3 changed files with 45 additions and 3 deletions

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fs/open.c

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