Andriy Gapon c59690f249 zfs+sendfile: populate all requested pages, not just those already cached ... kern_sendfile() uses vm_rdwr() to read-ahead blocks of data to populate page cache. When sendfile stumbles upon a page that is not populated yet, it sends out all the mbufs that it collected so far. This resulted in very poor performance with ZFS when file data is not in the page cache, because ZFS vop_read for UIO_NOCOPY case populated only those pages that are already in cache, but not valid. Which means that most of the time it populated only the first requested page in the described above scenario. Reported by: Alexander Zagrebin <alexz@visp.ru> Tested by: Alexander Zagrebin <alexz@visp.ru>, Artemiev Igor <ai@kliksys.ru> MFC after: 12 days		2010-11-16 15:53:44 +00:00
..
opensolaris	zfs+sendfile: populate all requested pages, not just those already cached	2010-11-16 15:53:44 +00:00