On Sat, 9 May 2015 11:49:01 +0300 (EEST) Julian Anastasov <[email protected]> wrote:
> > Hello, > > On Fri, 8 May 2015, Peter Zijlstra wrote: > > > Subject: sched: Introduce TASK_NOLOAD and TASK_IDLE > > From: Peter Zijlstra <[email protected]> > > Date: Fri May 8 14:23:45 CEST 2015 > > > > Currently people use TASK_INTERRUPTIBLE to idle kthreads and wait for > > 'work' because TASK_UNINTERRUPTIBLE contributes to the loadavg. Having > > all idle kthreads contribute to the loadavg is somewhat silly. > > > > Now mostly this works OK, because kthreads have all their signals > > masked. However there's a few sites where this is causing problems and > > TASK_UNINTERRUPTIBLE should be used, except for that loadavg issue. > > > > This patch adds TASK_NOLOAD which, when combined with > > TASK_UNINTERRUPTIBLE avoids the loadavg accounting. > > > > As most of imagined usage sites are loops where a thread wants to > > idle, waiting for work, a helper TASK_IDLE is introduced. > > After checking our code in net/netfilter/ipvs/ip_vs_sync.c, > sync_thread_master(), we may also need some wrappers: > > - schedule_timeout_idle (instead of schedule_timeout call): > __set_current_state(TASK_IDLE); > return schedule_timeout(timeout); > > - we here are really idle, so "N" looks ok yes, I would want wait_event_idle_timeout() and wait_event_idle() but I'll be happy to take whatever I can get :-) Thanks, NeilBrown > > - pair of __wait_event_idle(wq, condition) and > wait_event_idle(wq, condition) macros > > - we here are write-blocked for socket, not sure > if this blocked vs idle difference is useful to > represent, in new bit for this blocked state "B"=2048, > with 2 TASK_NOLOAD variants: N(idle) and B(blocked, > 2|1024|2048, eg. for read-blocked or write-blocked). > It will need additional argument 'state'/'blocked' for > *wait_event_idle(). > > Regards > > -- > Julian Anastasov <[email protected]>
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