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. ÂSo someone has called invoke_rcu_cpu_kthread(), >> >> > but rcu_cpu_kthread() is still blocked. ÂI 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. ÂSeem 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. Â(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. ÂThe 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. ÂI confess to still being quite puzzled! >> > >> > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ÂThanx, Paul >> > >> >> Here are the results of the Sedat's vote (European song contest :-)). > > ;-) > > Very strange. ÂRCU 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... ÂAnd more > diagnostics... > > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ÂThanx, Paul > "We are with you in spirit." ( Level XX from Hybris shooter-game on Amiga (1989) ) - Sedat - -- 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
