On Fri, Apr 22, 2011 at 07:36:58PM +0200, Sedat Dilek wrote: > On Fri, Apr 22, 2011 at 5:02 PM, Paul E. McKenney > <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > On Fri, Apr 22, 2011 at 11:40:54AM +0200, Sedat Dilek wrote: > >> On Fri, Apr 22, 2011 at 2:50 AM, Paul E. McKenney > >> <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > >> > On Thu, Apr 21, 2011 at 04:47:31PM +0200, Sedat Dilek wrote: > >> >> On Thu, Apr 21, 2011 at 4:28 PM, Paul E. McKenney > >> >> <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > >> >> > On Thu, Apr 21, 2011 at 02:49:37PM +0200, Sedat Dilek wrote: > >> >> >> On Thu, Apr 21, 2011 at 12:24 PM, Sedat Dilek > >> >> >> <sedat.dilek@xxxxxxxxxxxxxx> wrote: > >> > > >> > [ . . . ] > >> > > >> >> >> Here the results from the 2nd-run (PREEMPT_RCU enabled). > >> >> > > >> >> > OK, and the grace periods clearly stopped advancing early on. > >> >> > > >> >> > Beyond that point, the per-CPU kthread is blocked, but RCU has some > >> >> > work for it to do. So someone has called invoke_rcu_cpu_kthread(), > >> >> > but rcu_cpu_kthread() is still blocked. I don't see a bug right > >> >> > off-hand, but it is early in the morning for me, so I might easily > >> >> > be missing something. > >> >> > > >> >> > Hmmm... > >> >> > > >> >> > The synchronization between these two assumes that the per-CPU > >> >> > kthread is always bound to the respective CPU, so if was somehow > >> >> > being migrated off, that might explain these results. > >> >> > > >> >> > I will add some more diagnostics, test them locally, then push > >> >> > out an update. Seem reasonable? > >> >> > > >> >> > And thank you again for the testing!!! > >> >> > >> >> Ping me when you have new stuff for testing. > >> >> Tomorrow (friday), here is public holiday and monday, too. > >> >> So a looong weekend. > >> > > >> > ;-) > >> > > >> > OK, I have a new sedat.2011.04.21a branch in the -rcu git tree: > >> > > >> > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git > >> > > >> > This is against 2.6.39-rc3, as before. (Yes, I do need to rebase to > >> > 2.6.39-rc4, but didn't want to change any more than I had to.) > >> > > >> > I also have an updated script, which is attached. The output is similar > >> > to the earlier one, and it operated is pretty much the same way. > >> > > >> > Have a great weekend, and I look forward to seeing what shows up on > >> > this round. I confess to still being quite puzzled! > >> > > >> > Thanx, Paul > >> > > >> > >> Here are the results of the Sedat's vote (European song contest :-)). > > > > ;-) > > > > Very strange. RCU has told the per-CPU kthread that it needs to get > > to work, but this kthread is still waiting from RCU's viewpoint. > > Yet the "ps" command believes that this kthread is in fact runnable > > at SCHED_FIFO priority 1. > > > > I can tell that this one will require some thought... And more > > diagnostics... > > > > Thanx, Paul > > > > "We are with you in spirit." > > ( Level XX from Hybris shooter-game on Amiga (1989) ) OK, I added a few more diagnostics: sedat.2011.04.23a in -rcu: git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu.git When you get a chance, could you please give it a try? Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
