From: James Morse james.morse@arm.com
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@vger.kernel.org Cc: Fenghua Yu fenghua.yu@intel.com Cc: Reinette Chatre reinette.chatre@intel.com Signed-off-by: James Morse james.morse@arm.com Link: https://lore.kernel.org/r/20190624173656.202407-1-james.morse@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 @@ -655,7 +655,8 @@ 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 @@ -174,6 +174,7 @@ enum cpuhp_state { CPUHP_AP_WATCHDOG_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,