tree eb2f29fe8df7cb29be7d1bdda8dabe825f30f182
parent e3c0ac04f980750a368f7cd5f1b8d1d2cdc1f735
author Jeff Moyer <jmoyer@redhat.com> 1196840702 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1196875278 -0800

aio: only account I/O wait time in read_events if there are active requests

On 2.6.24, top started showing 100% iowait on one CPU when a UML instance was
running (but completely idle).  The UML code sits in io_getevents waiting for
an event to be submitted and completed.

Fix this by checking ctx->reqs_active before scheduling to determine whether
or not we are waiting for I/O.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>