Re: [patch 3/7] fs, notify: Add file handle entry intoinotify_inode_mark

From: Andrew Morton
Date: Tue Nov 13 2012 - 02:39:59 EST


On Tue, 13 Nov 2012 11:20:57 +0400 Cyrill Gorcunov <gorcunov@xxxxxxxxxx> wrote:

> > > struct inotify_inode_mark {
> > > struct fsnotify_mark fsn_mark;
> > > int wd;
> > > +#ifdef INOTIFY_USE_FHANDLE
> > > + __u8 fhandle[sizeof(struct file_handle) + MAX_HANDLE_SZ];
> > > +#endif
> > > };
> >
> > Whoa. This adds 128+8 bytes to the inotify_inode_mark. That's a lot of
> > bloat, and there can be a lot of inotify_inode_mark's in the system?
>
> Yes, that's why it's not turned on by default, only if is c/r turned on.
> iirc I've been said that usually only about 40 bytes is used (in the tests
> I met only 8 bytes). Letme re-check all things.

The question is, how many `struct inotify_inode_mark's are instantiated
system-wide? Could be millions?

Dumb question: do we really need inotify_inode_mark.fhandle at all?
What prevents us from assembling this info on demand when ->show_fdinfo() is
called?


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