diff options
author | Tony Luck <tony.luck@intel.com> | 2024-03-08 13:38:45 -0800 |
---|---|---|
committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-04-24 13:41:41 +0200 |
commit | e3ca96e479c91d6ee657d3caa5092a6a3a620f9f (patch) | |
tree | 078017617249dc7548fb9c1cc64136c4cddbb11e /arch/x86/kernel/cpu/resctrl/rdtgroup.c | |
parent | ed30a4a51bb196781c8058073ea720133a65596f (diff) |
x86/resctrl: Pass domain to target CPU
reset_all_ctrls() and resctrl_arch_update_domains() use on_each_cpu_mask()
to call rdt_ctrl_update() on potentially one CPU from each domain.
But this means rdt_ctrl_update() needs to figure out which domain to
apply changes to. Doing so requires a search of all domains in a resource,
which can only be done safely if cpus_lock is held. Both callers do hold
this lock, but there isn't a way for a function called on another CPU
via IPI to verify this.
Commit
c0d848fcb09d ("x86/resctrl: Remove lockdep annotation that triggers
false positive")
removed the incorrect assertions.
Add the target domain to the msr_param structure and call
rdt_ctrl_update() for each domain separately using
smp_call_function_single(). This means that rdt_ctrl_update() doesn't
need to search for the domain and get_domain_from_cpu() can safely
assert that the cpus_lock is held since the remaining callers do not use
IPI.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Link: https://lore.kernel.org/r/20240308213846.77075-2-tony.luck@intel.com
Diffstat (limited to 'arch/x86/kernel/cpu/resctrl/rdtgroup.c')
-rw-r--r-- | arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 011e17efb1a6..02f213f1c51c 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2813,16 +2813,12 @@ static int reset_all_ctrls(struct rdt_resource *r) struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); struct rdt_hw_domain *hw_dom; struct msr_param msr_param; - cpumask_var_t cpu_mask; struct rdt_domain *d; int i; /* Walking r->domains, ensure it can't race with cpuhp */ lockdep_assert_cpus_held(); - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - msr_param.res = r; msr_param.low = 0; msr_param.high = hw_res->num_closid; @@ -2834,17 +2830,13 @@ static int reset_all_ctrls(struct rdt_resource *r) */ list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); - cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); for (i = 0; i < hw_res->num_closid; i++) hw_dom->ctrl_val[i] = r->default_ctrl; + msr_param.dom = d; + smp_call_function_any(&d->cpu_mask, rdt_ctrl_update, &msr_param, 1); } - /* Update CBM on all the CPUs in cpu_mask */ - on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); - - free_cpumask_var(cpu_mask); - return 0; } |