Messages in this thread | | | Date | Wed, 14 Aug 2013 19:31:03 +0200 | From | Ingo Molnar <> | Subject | Re: [GIT PULL] timers/nohz updates for 3.12 |
| |
* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> On Tue, Aug 13, 2013 at 04:57:30PM +0200, Ingo Molnar wrote: > > > > * Frederic Weisbecker <fweisbec@gmail.com> wrote: > > > > > > > 19 files changed, 534 insertions(+), 326 deletions(-) > > > > > > > > When merged to -tip it causes this build error: > > > > > > > > kernel/time/tick-sched.c:186:3: error: 'have_nohz_full_mask' undeclared (first use in this function) > > > > kernel/time/tick-sched.c:345:2: error: 'cpu' undeclared (first use in this function) > > > > > > > > config attached. > > > > > > > > I did what looked like to be an obvious conflict resolution to > > > > tick-sched.c (attached), please double check that too. > > > > > > > > While at it, mind rebasing your changes to tip:timers/urgent, which has a > > > > few nohz fixes pending as well? > > > > > > Ok I did the rebase on top of tip:timers/urgent and handled the > > > conflicts along. The new branch is "timers/nohz-v2". > > > > > > Tell me if anything goes wrong with it. > > > > it produces this splat on bootup with the attached config, on a dual-core > > Athlon64 box: > > > > calling context_tracking_init+0x0/0x3a @ 1 > > initcall context_tracking_init+0x0/0x3a returned 0 after 0 usecs > > calling dynamic_debug_init+0x0/0x239 @ 1 > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 1 at kernel/sched/cputime.c:639 get_vtime_delta+0x49/0x5f() > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.11.0-rc5-01689-g7830cba-dirty #226899 > > Hardware name: System manufacturer System Product Name/A8N-E, BIOS ASUS A8N-E ACPI BIOS Revision 1008 08/22/2005 > > 0000000000000009 ffff88003fa03ea8 ffffffff81f83f30 0000000000000b63 > > 0000000000000000 ffff88003fa03ee8 ffffffff810996a4 0000000000000000 > > ffffffff810bcfb5 ffff88003e33a000 0000000015752a00 0000000000000000 > > Call Trace: > > <IRQ> [<ffffffff81f83f30>] dump_stack+0x46/0x58 > > [<ffffffff810996a4>] warn_slowpath_common+0x72/0x8c > > [<ffffffff810bcfb5>] ? get_vtime_delta+0x49/0x5f > > [<ffffffff8109976c>] warn_slowpath_null+0x15/0x19 > > [<ffffffff810bcfb5>] get_vtime_delta+0x49/0x5f > > [<ffffffff810bd213>] __vtime_account_system+0xf/0x37 > > [<ffffffff810bd426>] vtime_account_system+0x21/0x2e > > [<ffffffff810bd5bf>] vtime_common_account_irq_enter+0x41/0x43 > > [<ffffffff8109ce4a>] irq_enter+0x65/0x7c > > [<ffffffff810434e2>] smp_apic_timer_interrupt+0x23/0x40 > > [<ffffffff81f9435d>] apic_timer_interrupt+0x6d/0x80 > > <EOI> [<ffffffff810c42d5>] ? arch_local_irq_restore+0x12/0x19 > > [<ffffffff810c5acb>] vprintk_emit+0x3e2/0x40a > > [<ffffffff81099995>] ? cpu_maps_update_begin+0x12/0x14 > > [<ffffffff832e9244>] ? ddebug_setup_query+0x4d/0x4d > > [<ffffffff81f80ddd>] printk+0x5c/0x5e > > [<ffffffff8135caff>] __dynamic_pr_debug+0x79/0x7b > > [<ffffffff810c764d>] ? timekeeping_get_ns.constprop.10+0x12/0x38 > > [<ffffffff832db12b>] ? init_hw_breakpoint+0xf7/0xf7 > > [<ffffffff810c7bbb>] ? ktime_get+0x65/0x74 > > [<ffffffff832db12b>] ? init_hw_breakpoint+0xf7/0xf7 > > [<ffffffff832e9244>] ? ddebug_setup_query+0x4d/0x4d > > [<ffffffff832c4d9d>] do_one_initcall+0x5b/0x12a > > [<ffffffff832d09a5>] ? native_smp_prepare_cpus+0x300/0x341 > > [<ffffffff832c4ed6>] kernel_init_freeable+0x6a/0x195 > > [<ffffffff81f7c075>] ? rest_init+0xb9/0xb9 > > [<ffffffff81f7c07e>] kernel_init+0x9/0xd1 > > [<ffffffff81f9357c>] ret_from_fork+0x7c/0xb0 > > [<ffffffff81f7c075>] ? rest_init+0xb9/0xb9 > > ---[ end trace 268f4433da36e82f ]--- > > initcall dynamic_debug_init+0x0/0x239 returned 0 after 0 usecs > > > > Thanks, > > > > Ingo > > Sorry about that, I missed it. This is because context tracking > initialization when CONFIG_CONTEXT_TRACKING_FORCE=y is done too late. As > a result, the user init task can run with context tracking disabled when > it is scheduled for the first time and then later run with context > tracking enabled due to the late initialization. And this finally messes > up the state of context tracking internal on CPU 0. > > Anyway I fixed this by moving the context tracking initialization > earlier, before irqs are enabled and the user init task is created. > > Please check out the branch "timers/nohz-v3". > > Only commit "context_tracking: Ground setup for static key use" which is > now 65f382fd0c8fa483713c0971de9f1dfb4cf1ad9c has changed to integrate > the fix. > > And following is the diff against the previous branch.
Pulled, thanks Frederic! Seems to be working better now.
Thanks,
Ingo
| |