K 10
svn:author
V 7
glebius
K 8
svn:date
V 27
2016-11-17T21:02:55.139072Z
K 7
svn:log
V 602
Use bogus_page to properly reduce number of I/Os in sendfile(2).  The new
sendfile_swapin() loop works this way:

- Find first invalid page in the request.
- Do vm_pager_has_page() and get count of pages, that can be taken in
  single I/O.
- Trim valid pages from the end of the request.
- Cycle through the request and substitute to bogus_page all valid
  pages that are in the middle of the request.
- After I/O launched (pager copies array of pages into buf(9), it
  is important to restore proper page pointers with help vm_page_lookup().

Count bogus pages used and report them in sendfile stats.

END