2018-05-12 7:07 GMT+02:00 Michael van Elst <mlel...@serpens.de>: > On Fri, May 11, 2018 at 05:28:18PM +0200, Jaromír Dole?ek wrote: >> I've implemented a tweak to read-ahead code to skip the full >> read-ahead if last page of the range is already in cache, this >> improved things a lot: > > That looks a bit like a hack. Can't you just call uvm_pagelookup() > to determine if the last page is cached? Or if that's too UVM internal, > call uvm_findpages() with UFP_NOALLOC.
I thought it would be less abstraction violation when done in getpages. But actually using uvm_pagelookup() seems to be fine from that standpoint. Furthermore, it avoids some page flag manipulation, and makes the change much more localized, to only uvm_readahead.c. So I'll go with that. Thanks. Jaromir