From: James Morse <james.morse@xxxxxxx>
commit 83b44fe343b5abfcb1b2261289bd0cfcfcfd60a8 upstream.
The cacheinfo structures are alloced/freed by cpu online/offline
callbacks. Originally these were only used by sysfs to expose the
cache topology to user space. Without any in-kernel dependencies
CPUHP_AP_ONLINE_DYN was an appropriate choice.
resctrl has started using these structures to identify CPUs that
share a cache. It updates its 'domain' structures from cpu
online/offline callbacks. These depend on the cacheinfo structures
(resctrl_online_cpu()->domain_add_cpu()->get_cache_id()->
get_cpu_cacheinfo()).
These also run as CPUHP_AP_ONLINE_DYN.
Now that there is an in-kernel dependency, move the cacheinfo
work earlier so we know its done before resctrl's CPUHP_AP_ONLINE_DYN
work runs.
Fixes: 2264d9c74dda1 ("x86/intel_rdt: Build structures for each resource based on cache topology")
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
Link: https://lore.kernel.org/r/20190624173656.202407-1-james.morse@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/cacheinfo.c | 3 ++-
include/linux/cpuhotplug.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -669,7 +669,8 @@ static int cacheinfo_cpu_pre_down(unsign
static int __init cacheinfo_sysfs_init(void)
{
- return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
+ return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
+ "base/cacheinfo:online",
cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
}
device_initcall(cacheinfo_sysfs_init);
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -163,6 +163,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
CPUHP_AP_WORKQUEUE_ONLINE,
CPUHP_AP_RCUTREE_ONLINE,
+ CPUHP_AP_BASE_CACHEINFO_ONLINE,
CPUHP_AP_ONLINE_DYN,
CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
CPUHP_AP_X86_HPET_ONLINE,
