On Thu, 2023-09-28 at 11:48 -0400, Arnd Bergmann wrote: > On Thu, Sep 28, 2023, at 07:05, Jeff Layton wrote: > > This shaves 8 bytes off struct inode, according to pahole. > > > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > > FWIW, this is similar to the approach that Deepa suggested > back in 2016: > > https://lore.kernel.org/lkml/1452144972-15802-3-git-send-email-deepa.kernel@xxxxxxxxx/ > > It was NaKed at the time because of the added complexity, > though it would have been much easier to do it then, > as we had to touch all the timespec references anyway. > > The approach still seems ok to me, but I'm not sure it's worth > doing it now if we didn't do it then. > I remember seeing those patches go by. I don't remember that change being NaK'ed, but I wasn't paying close attention at the time Looking at it objectively now, I think it's worth it to recover 8 bytes per inode and open a 4 byte hole that Amir can use to grow the i_fsnotify_mask. We might even able to shave off another 12 bytes eventually if we can move to a single 64-bit word per timestamp. It is a lot of churn though. -- Jeff Layton <jlayton@xxxxxxxxxx>
