Alterations to the pipe code in the kernel made it possible for relative starvation to occur with tasks that slept waiting on a pipe getting unfair priority bonuses even if they were otherwise fully cpu bound so the TASK_NONINTERACTIVE flag was introduced which prevented any change to sleep_avg while sleeping waiting on a pipe. This change also leads to the converse though, preventing any priority boost from occurring in truly interactive tasks that wait on pipes. Convert the TASK_NONINTERACTIVE flag to set sleep_type to SLEEP_NONINTERACTIVE which will allow a linear bonus to priority based on sleep time thus allowing interactive tasks to get high priority if they sleep enough. Signed-off-by: Con Kolivas <[email protected]> kernel/sched.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) Index: linux-2.6.15/kernel/sched.c =================================================================== --- linux-2.6.15.orig/kernel/sched.c +++ linux-2.6.15/kernel/sched.c @@ -1348,18 +1348,18 @@ out_activate: * cpu bound so label them as noninteractive. */ p->sleep_type = SLEEP_NONINTERACTIVE; - } + } else /* * Tasks that have marked their sleep as noninteractive get - * woken up without updating their sleep average. (i.e. their - * sleep is handled in a priority-neutral manner, no priority - * boost and no penalty.) + * woken up with their sleep average not weighted in an + * interactive way. */ - if (old_state & TASK_NONINTERACTIVE) - __activate_task(p, rq); - else - activate_task(p, rq, cpu == this_cpu); + if (old_state & TASK_NONINTERACTIVE) + p->sleep_type = SLEEP_NONINTERACTIVE; + + + activate_task(p, rq, cpu == this_cpu); /* * Sync wakeups (i.e. those types of wakeups where the waker * has indicated that it will leave the CPU in short order)
Attachment:
pgp3yWxXNcw6e.pgp
Description: PGP signature
- Prev by Date: [PATCH 0/5] sched - interactivity updates
- Next by Date: [PATCH 2/5] sched-alter_uninterruptible_sleep_interactivity.patch
- Previous by thread: [PATCH 0/5] sched - interactivity updates
- Next by thread: [PATCH 2/5] sched-alter_uninterruptible_sleep_interactivity.patch
- Index(es):
 |