Messages in this thread | | | Date | Tue, 29 Jul 2014 16:31:30 +0900 | From | Yasuaki Ishimatsu <> | Subject | Re: [PATCH v2] x86, hotplug: fix llc shared map unreleased during cpu hotplug |
| |
Hi Wanpeng,
(2014/07/29 16:06), Wanpeng Li wrote: > Hi Yasuaki, > On Wed, Jul 23, 2014 at 05:56:07PM +0900, Yasuaki Ishimatsu wrote: >> (2014/07/22 17:04), Wanpeng Li wrote: >>> [ 220.262093] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 >>> [ 220.262104] IP: [<ffffffff810e7ac9>] find_busiest_group+0x2b9/0xa30 >>> [ 220.262111] PGD 5a9d5067 PUD 13067 PMD 0 >>> [ 220.262117] Oops: 0000 [#3] SMP >>> [...] >>> [ 220.262245] Call Trace: >>> [ 220.262252] [<ffffffff810e8396>] load_balance+0x156/0x980 >>> [ 220.262259] [<ffffffff816eeffe>] ? _raw_spin_unlock_irqrestore+0x2e/0xa0 >>> [ 220.262266] [<ffffffff810e9aa3>] idle_balance+0xe3/0x150 >>> [ 220.262270] [<ffffffff816ec4e7>] __schedule+0x797/0x8d0 >>> [ 220.262277] [<ffffffff816ec934>] schedule+0x24/0x70 >>> [ 220.262283] [<ffffffff816e9cd9>] schedule_timeout+0x119/0x1f0 >>> [ 220.262294] [<ffffffff810bb6e0>] ? lock_timer_base+0x70/0x70 >>> [ 220.262301] [<ffffffff816e9dc9>] schedule_timeout_uninterruptible+0x19/0x20 >>> [ 220.262308] [<ffffffff810bd3e8>] msleep+0x18/0x20 >>> [ 220.262317] [<ffffffff813aa11a>] lock_device_hotplug_sysfs+0x2a/0x50 >>> [ 220.262323] [<ffffffff813aa16e>] online_store+0x2e/0x80 >>> [ 220.262358] [<ffffffff813a873b>] dev_attr_store+0x1b/0x20 >>> [ 220.262366] [<ffffffff812292fd>] sysfs_write_file+0xdd/0x160 >>> [ 220.262377] [<ffffffff811b7e78>] vfs_write+0xc8/0x170 >>> [ 220.262384] [<ffffffff811b83ca>] SyS_write+0x5a/0xa0 >>> [ 220.262388] [<ffffffff816f76b9>] system_call_fastpath+0x16/0x1b >>> >>> Last level cache shared map is built during cpu up and build sched domain >>> routine takes advantage of it to setup sched domain cpu topology, however, >>> llc shared map is unreleased during cpu disable which lead to invalid sched >>> domain cpu topology. This patch fix it by release llc shared map correctly >>> during cpu disable. >>> >> >> I posted a latest patch as follows: >> https://lkml.org/lkml/2014/7/22/1018 >> >> Could you confirm the patch fixes your issue? > > Sorry for the late, there is still call trace w/ your patch applied. The > call trace is in attachment.
Thank you for reporting the result. As Borislav said, your v2 patch is necessary for fixing your issue.
> > Regards, > Wanpeng Li > >> >> Thanks, >> Yasuaki Ishimatsu >> >>> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Thanks, Yasuaki Ishimatsu
>>> --- >>> v1 -> v2: >>> * fix subject line >>> >>> arch/x86/kernel/smpboot.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c >>> index 5492798..0134ec7 100644 >>> --- a/arch/x86/kernel/smpboot.c >>> +++ b/arch/x86/kernel/smpboot.c >>> @@ -1292,6 +1292,9 @@ static void remove_siblinginfo(int cpu) >>> >>> for_each_cpu(sibling, cpu_sibling_mask(cpu)) >>> cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling)); >>> + for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) >>> + cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling)); >>> + cpumask_clear(cpu_llc_shared_mask(cpu)); >>> cpumask_clear(cpu_sibling_mask(cpu)); >>> cpumask_clear(cpu_core_mask(cpu)); >>> c->phys_proc_id = 0; >>> >>
| |