Messages in this thread | | | Date | Sun, 28 Mar 2004 18:53:47 +0200 | From | Takashi Iwai <> | Subject | Re: [PATCH] RCU for low latency (experimental) |
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At Thu, 25 Mar 2004 05:16:43 +0530, Dipankar Sarma wrote: > > On Thu, Mar 25, 2004 at 12:34:30AM +0100, Andrea Arcangeli wrote: > > On Thu, Mar 25, 2004 at 04:41:45AM +0530, Dipankar Sarma wrote: > > > That was not 16 callbacks per tick, it was 16 callbacks in one > > > batch of a single softirq. And then I reschedule the RCU tasklet > > > > sorry so you're already using tasklets in current code? I misunderstood > > the current code then. > > + if (count >= rcumaxbatch) { > + RCU_plugticks(cpu) = rcuplugticks; > + if (!RCU_plugticks(cpu)) > + tasklet_hi_schedule(&RCU_tasklet(cpu)); > + break; > + }
it seems count is never incremented in your patch... or am i missing something?
anyway, i confirmed that with the original krcud patch the latency with dcache flood can be eliminated.
for the non-preemptive case, rcu_bh_callback_limit() should return bhlimit always, though. otherwise cond_resched() isn't called in the callback loop properly.
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