Hi, * Andrea Arcangeli wrote: > On Sun, Jun 21, 2009 at 11:05:28PM +0200, Rocco Rutte wrote:
> > points that would have to be solved to get the patch ready for > > inclusion. For example test if posix_fadvise() is available, why only > > That requires a configure knob? No, simply test for its existence, and wrap the code in hcache.c in #ifdef/#endif. There's no need for a knob. > > do that for tokyocabinet, etc. Note that we're in a feature-freeze to > > No good reason to do it only for tokyocabinet indeed. But if one wants > performance he should use something with compression so that one reads > 1/5th of the data at 3 times the speed with fadvise than without > fadvise. Well, as tokyocabinet is the successor of qdbm, qdbm has compression, too. I don't know about DB4, but the other 3 should have that function even if the benefit is only a few percent. > Cumulatively compression and fadvise reduce the opening time > tenfold, ignoring the time it actually takes to process the data by > the db lib after the I/O is complete. I agree we should add fadvise to > all backends even if it makes little sense to use anything but > tokyocabinet. Care to provide some details why it makes no sense to use qdbm? :-) > > It's there because mutt displays what the mailbox has, not what the > > cache has. The cur/ directory may change greatly between to mutt > > sessions (e.g. a sync using unison, rsync, etc). I can't imagine > > dropping it (except for a replacement mechanism that tells us what files > > there are). > What if I can guarantee you that I don't modify the 'cur' directory > under 'mutt'. The only thing that touches my maildir are procmail in > 'tmp' and 'new' and mutt in 'cur' and 'new'. Nothing else ever touches > my maildir, so I definitely need a knob to disable readdir on 'cur' > and to only have readdir on 'new' when opening a maildir so with the > addition of fadvise and tokyocabinet compression things will fly even > for large folders with 150k mails ;). Yes, I see your point. The only thing I'm sure is that your guarantee shouldn't be generalized. :) What not sure about is whether we really want an option for it. Hacking this isn't exactly trivial either given that the current code of two pass maildir parsing. Rocco
