Messages in this thread Patch in this message | | | Date | Wed, 21 Feb 2024 11:31:18 -0800 | From | Tony Luck <> | Subject | [PATCH v2] x86/resctrl: Fix WARN in get_domain_from_cpu() |
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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.
Fix by adding the target domain to the msr_param structure and passing an array with CDP_NUM_TYPES entries. Then calling for each domain separately using smp_call_function_single()
Change the low level cat_wrmsr(), mba_wrmsr_intel(), and mba_wrmsr_amd() functions to just take a msr_param structure since it contains the rdt_resource and rdt_domain information.
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
Changes since v1:
* Avoid double IPI to the same core when CDP is enabled. * Don't pass the resource and domain to functions that can get these from the msr_param structure. * Clean up some fir tree issues in functions that I changed.
arch/x86/kernel/cpu/resctrl/internal.h | 4 +- arch/x86/kernel/cpu/resctrl/core.c | 56 +++++++++------------ arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 59 +++++++---------------- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 23 ++++----- 4 files changed, 50 insertions(+), 92 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index c99f26ebe7a6..2f21358b9621 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -383,6 +383,7 @@ static inline struct rdt_hw_domain *resctrl_to_arch_dom(struct rdt_domain *r) */ struct msr_param { struct rdt_resource *res; + struct rdt_domain *dom; u32 low; u32 high; }; @@ -442,8 +443,7 @@ struct rdt_hw_resource { struct rdt_resource r_resctrl; u32 num_closid; unsigned int msr_base; - void (*msr_update) (struct rdt_domain *d, struct msr_param *m, - struct rdt_resource *r); + void (*msr_update)(struct msr_param *m); unsigned int mon_scale; unsigned int mbm_width; unsigned int mbm_cfg_mask; diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 8a4ef4f5bddc..643bf64bf1be 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -56,14 +56,9 @@ int max_name_width, max_data_width; */ bool rdt_alloc_capable; -static void -mba_wrmsr_intel(struct rdt_domain *d, struct msr_param *m, - struct rdt_resource *r); -static void -cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r); -static void -mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m, - struct rdt_resource *r); +static void mba_wrmsr_intel(struct msr_param *m); +static void cat_wrmsr(struct msr_param *m); +static void mba_wrmsr_amd(struct msr_param *m); #define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].r_resctrl.domains) @@ -309,12 +304,11 @@ static void rdt_get_cdp_l2_config(void) rdt_get_cdp_config(RDT_RESOURCE_L2); } -static void -mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r) +static void mba_wrmsr_amd(struct msr_param *m) { + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(m->res); + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(m->dom); unsigned int i; - struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); for (i = m->low; i < m->high; i++) wrmsrl(hw_res->msr_base + i, hw_dom->ctrl_val[i]); @@ -334,25 +328,22 @@ static u32 delay_bw_map(unsigned long bw, struct rdt_resource *r) return r->default_ctrl; } -static void -mba_wrmsr_intel(struct rdt_domain *d, struct msr_param *m, - struct rdt_resource *r) +static void mba_wrmsr_intel(struct msr_param *m) { + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(m->res); + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(m->dom); unsigned int i; - struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); /* Write the delay values for mba. */ for (i = m->low; i < m->high; i++) - wrmsrl(hw_res->msr_base + i, delay_bw_map(hw_dom->ctrl_val[i], r)); + wrmsrl(hw_res->msr_base + i, delay_bw_map(hw_dom->ctrl_val[i], m->res)); } -static void -cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r) +static void cat_wrmsr(struct msr_param *m) { + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(m->res); + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(m->dom); unsigned int i; - struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); for (i = m->low; i < m->high; i++) wrmsrl(hw_res->msr_base + i, hw_dom->ctrl_val[i]); @@ -387,19 +378,14 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r) void rdt_ctrl_update(void *arg) { + struct rdt_hw_resource *hw_res; struct msr_param *m = arg; - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(m->res); - struct rdt_resource *r = m->res; - int cpu = smp_processor_id(); - struct rdt_domain *d; + int t; - d = get_domain_from_cpu(cpu, r); - if (d) { - hw_res->msr_update(d, m, r); - return; - } - pr_warn_once("cpu %d not found in any domain for resource %s\n", - cpu, r->name); + hw_res = resctrl_to_arch_res(m->res); + for (t = 0; t < CDP_NUM_TYPES; t++) + if (m[t].dom) + hw_res->msr_update(m + t); } /* @@ -472,9 +458,11 @@ static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d) hw_dom->ctrl_val = dc; setup_default_ctrlval(r, dc); + m.res = r; + m.dom = d; m.low = 0; m.high = hw_res->num_closid; - hw_res->msr_update(d, &m, r); + hw_res->msr_update(&m); return 0; } diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 7997b47743a2..09f6e624f1bb 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -272,22 +272,6 @@ static u32 get_config_index(u32 closid, enum resctrl_conf_type type) } } -static bool apply_config(struct rdt_hw_domain *hw_dom, - struct resctrl_staged_config *cfg, u32 idx, - cpumask_var_t cpu_mask) -{ - struct rdt_domain *dom = &hw_dom->d_resctrl; - - if (cfg->new_ctrl != hw_dom->ctrl_val[idx]) { - cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask); - hw_dom->ctrl_val[idx] = cfg->new_ctrl; - - return true; - } - - return false; -} - int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type t, u32 cfg_val) { @@ -304,59 +288,50 @@ int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d, msr_param.res = r; msr_param.low = idx; msr_param.high = idx + 1; - hw_res->msr_update(d, &msr_param, r); + hw_res->msr_update(&msr_param); return 0; } int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) { + struct msr_param msr_param[CDP_NUM_TYPES]; struct resctrl_staged_config *cfg; struct rdt_hw_domain *hw_dom; - struct msr_param msr_param; enum resctrl_conf_type t; - cpumask_var_t cpu_mask; struct rdt_domain *d; + bool need_update; + int cpu; u32 idx; /* 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 = NULL; + memset(msr_param, 0, sizeof(msr_param)); list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); + need_update = false; for (t = 0; t < CDP_NUM_TYPES; t++) { cfg = &hw_dom->d_resctrl.staged_config[t]; if (!cfg->have_new_ctrl) continue; idx = get_config_index(closid, t); - if (!apply_config(hw_dom, cfg, idx, cpu_mask)) + if (cfg->new_ctrl == hw_dom->ctrl_val[idx]) continue; - - if (!msr_param.res) { - msr_param.low = idx; - msr_param.high = msr_param.low + 1; - msr_param.res = r; - } else { - msr_param.low = min(msr_param.low, idx); - msr_param.high = max(msr_param.high, idx + 1); - } + hw_dom->ctrl_val[idx] = cfg->new_ctrl; + cpu = cpumask_any(&d->cpu_mask); + + msr_param[t].low = idx; + msr_param[t].high = msr_param[t].low + 1; + msr_param[t].res = r; + msr_param[t].dom = d; + need_update = true; } + if (need_update) + smp_call_function_single(cpu, rdt_ctrl_update, &msr_param, 1); } - if (cpumask_empty(cpu_mask)) - goto done; - - /* Update resource control msr on all the CPUs. */ - on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); - -done: - free_cpumask_var(cpu_mask); - return 0; } diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 011e17efb1a6..5d9ff8883c60 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2811,21 +2811,19 @@ static int rdt_init_fs_context(struct fs_context *fc) static int reset_all_ctrls(struct rdt_resource *r) { struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); + struct msr_param msr_param[CDP_NUM_TYPES]; struct rdt_hw_domain *hw_dom; - struct msr_param msr_param; - cpumask_var_t cpu_mask; struct rdt_domain *d; + int cpu; 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; + memset(msr_param, 0, sizeof(msr_param)); + msr_param[0].res = r; + msr_param[0].low = 0; + msr_param[0].high = hw_res->num_closid; /* * Disable resource control for this resource by setting all @@ -2834,17 +2832,14 @@ 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); + cpu = cpumask_any(&d->cpu_mask); for (i = 0; i < hw_res->num_closid; i++) hw_dom->ctrl_val[i] = r->default_ctrl; + msr_param[0].dom = d; + smp_call_function_single(cpu, 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; } -- 2.43.0
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