Messages in this thread | | | Date | Tue, 9 Jun 2015 14:13:00 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v6] procfs: Always expose /proc/<pid>/map_files/ and make it readable |
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On Mon, 8 Jun 2015 20:39:33 -0700 Calvin Owens <calvinowens@fb.com> wrote:
> Currently, /proc/<pid>/map_files/ is restricted to CAP_SYS_ADMIN, and > is only exposed if CONFIG_CHECKPOINT_RESTORE is set. > > This interface very useful because it allows userspace to stat() > deleted files that are still mapped by some process, which enables a > much quicker and more accurate answer to the question "How much disk > space is being consumed by files that are deleted but still mapped?" > than is currently possible.
Why is that information useful?
I could perhaps think of some use for "How much disk space is being consumed by files that are deleted but still open", but to count the mmapped-then-unlinked files while excluding the opened-then-unlinked files seems damned peculiar.
IOW, this changelog failed to explain the value of the patch. Bad changelog! Please sell it to us. Preferably with real-world use cases.
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