On Thu 01-06-17 13:34:34, Jan Kara wrote: > On Thu 01-06-17 11:26:08, David Howells wrote: > > Jan Kara <jack@xxxxxxx> wrote: > > > > > The callback doesn't ever get called. Remove it. > > > > Hmmm... I should perhaps be calling this. I'm not sure why I never did. > > > > At the moment, it doesn't strictly matter as ops on pages marked with > > PG_fscache get ignored if the cache has suffered an I/O error or has been > > withdrawn - but it will incur a performance penalty (the PG_fscache flag is > > checked in the netfs before calling into fscache). > > > > The downside of calling this is that when a cache is removed, fscache would go > > through all the cookies for that cache and iterate over all the pages > > associated with those cookies - which could cause a performance dip in the > > system. > > So I know nothing about fscache. If you decide these functions should stay > in as you are going to use them soon, then I can just convert them to the > new API as everything else. What just caught my eye and why I had a more > detailed look is that I didn't understand that 'PAGEVEC_SIZE - > pagevec_count(&pvec)' as a pagevec_lookup() argument since pagevec_count() > should always return 0 at that point? David, what is your final decision regarding this? Do you want to keep these unused functions (and I will just update my patch to convert them to the new calling convention) or will you apply the patch to remove them? Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
