Messages in this thread | | | From | Gu Zheng <> | Subject | [PATCH 0/2] workqueue: fix a bug when numa mapping is changed | Date | Thu, 26 Mar 2015 10:17:53 +0800 |
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Yasuaki Ishimatsu found that with node online/offline, cpu<->node relationship is established. Because workqueue uses a info which was established at boot time, but it may be changed by node hotpluging.
Once pool->node points to a stale node, following allocation failure happens. == SLUB: Unable to allocate memory on node 2 (gfp=0x80d0) cache: kmalloc-192, object size: 192, buffer size: 192, default order: 1, min order: 0 node 0: slabs: 6172, objs: 259224, free: 245741 node 1: slabs: 3261, objs: 136962, free: 127656 ==
As the apicid <--> node relationship is persistent, so the root cause is the cpu-id <-> lapicid mapping is not persistent (because the currently implementation always choose the first free cpu id for the new added cpu), so if we can build persistent cpu-id <-> lapicid relationship, this problem will be fixed.
Please refer to https://lkml.org/lkml/2015/2/27/145 for the previous discussion.
Gu Zheng (2): x86/cpu hotplug: make lapicid <-> cpuid mapping persistent workqueue: update per cpu workqueue's numa affinity when cpu preparing online
arch/x86/kernel/apic/apic.c | 31 ++++++++++++++++++++++++++++++- kernel/workqueue.c | 1 + 2 files changed, 31 insertions(+), 1 deletions(-)
-- 1.7.7
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