Messages in this thread Patch in this message | | | From | James Morse <> | Subject | [PATCH v1 06/20] x86/resctrl: Switch over to the resctrl mbps_val list | Date | Thu, 29 Jul 2021 22:35:56 +0000 |
| |
Updates to resctrl's software controller follow the same path as other configuration updates, but they don't modify the hardware state. rdtgroup_schemata_write() uses parse_line() and the resource's ctrlval_parse function to stage the configuration. resctrl_arch_update_domains() then updates the mbps_val[] array instead, and resctrl_arch_update_domains() skips the rdt_ctrl_update() call that would update hardware.
This complicates the interface between resctrl's filesystem parts and architecture specific code. It should be possible for mba_sc to be completely implemented by the filesystem parts of resctrl. This would allow it to work on a second architecture with no additional code.
Change parse_bw() to write the configuration value directly to the mba_sc[] array in the domain structure. Change rdtgroup_schemata_write() to skip the call to resctrl_arch_update_domains(), meaning all the mba_sc specific code in resctrl_arch_update_domains() can be removed. On the read-side, show_doms() and update_mba_bw() are changed to read the mba_sc[] array from the domain structure. With this, resctrl_arch_get_config() no longer needs to consider mba_sc resources.
Change parse_bw() to write these values directly, meaning rdtgroup_schemata_write() never needs to call update_domains() for mba_sc resources.
Get show_doms() to test is_mba_sc() and retrieve the value directly, instead of using get_config() for the hardware value.
This means the arch code's resctrl_arch_get_config() and resctrl_arch_update_domains() no longer need to be aware of mba_sc, and we can get rid of the update_mba_bw() code that reaches into the hw_dom to get the msr value.
Signed-off-by: James Morse <james.morse@arm.com> --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 45 ++++++++++++++--------- arch/x86/kernel/cpu/resctrl/monitor.c | 10 ++--- 2 files changed, 31 insertions(+), 24 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 9e1c6730520b..56789ea11185 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -61,6 +61,7 @@ int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, struct rdt_domain *d) { struct resctrl_staged_config *cfg; + u32 closid = data->rdtgrp->closid; struct rdt_resource *r = s->res; unsigned long bw_val; @@ -72,6 +73,12 @@ int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, if (!bw_validate(data->buf, &bw_val, r)) return -EINVAL; + + if (is_mba_sc(r)) { + d->mba_sc[closid].mbps_val = bw_val; + return 0; + } + cfg->new_ctrl = bw_val; cfg->have_new_ctrl = true; @@ -261,14 +268,13 @@ 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, bool mba_sc) + cpumask_var_t cpu_mask) { struct rdt_domain *dom = &hw_dom->d_resctrl; - u32 *dc = !mba_sc ? hw_dom->ctrl_val : hw_dom->mbps_val; - if (cfg->new_ctrl != dc[idx]) { + if (cfg->new_ctrl != hw_dom->ctrl_val[idx]) { cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask); - dc[idx] = cfg->new_ctrl; + hw_dom->ctrl_val[idx] = cfg->new_ctrl; return true; } @@ -284,14 +290,12 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) enum resctrl_conf_type t; cpumask_var_t cpu_mask; struct rdt_domain *d; - bool mba_sc; int cpu; u32 idx; if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) return -ENOMEM; - mba_sc = is_mba_sc(r); msr_param.res = NULL; list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); @@ -301,7 +305,7 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) continue; idx = get_config_index(closid, t); - if (!apply_config(hw_dom, cfg, idx, cpu_mask, mba_sc)) + if (!apply_config(hw_dom, cfg, idx, cpu_mask)) continue; if (!msr_param.res) { @@ -315,11 +319,7 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) } } - /* - * Avoid writing the control msr with control values when - * MBA software controller is enabled - */ - if (cpumask_empty(cpu_mask) || mba_sc) + if (cpumask_empty(cpu_mask)) goto done; cpu = get_cpu(); /* Update resource control msr on this CPU if it's in cpu_mask. */ @@ -406,6 +406,14 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, list_for_each_entry(s, &resctrl_schema_all, list) { r = s->res; + + /* + * Writes to mba_sc resources update the software controller, + * not the control msr. + */ + if (is_mba_sc(r)) + continue; + ret = resctrl_arch_update_domains(r, rdtgrp->closid); if (ret) goto out; @@ -433,10 +441,7 @@ void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); u32 idx = get_config_index(closid, type); - if (!is_mba_sc(r)) - *value = hw_dom->ctrl_val[idx]; - else - *value = hw_dom->mbps_val[idx]; + *value = hw_dom->ctrl_val[idx]; } static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) @@ -451,8 +456,12 @@ static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int clo if (sep) seq_puts(s, ";"); - resctrl_arch_get_config(r, dom, closid, schema->conf_type, - &ctrl_val); + if (is_mba_sc(r)) + ctrl_val = dom->mba_sc[closid].mbps_val; + else + resctrl_arch_get_config(r, dom, closid, + schema->conf_type, &ctrl_val); + seq_printf(s, r->format_str, dom->id, max_data_width, ctrl_val); sep = true; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 035e45e711ae..dcf3a73e2c17 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -442,13 +442,11 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm) hw_dom_mba = resctrl_to_arch_dom(dom_mba); cur_bw = pmbm_data->prev_bw; - resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE, &user_bw); + user_bw = dom_mba->mba_sc[closid].mbps_val; delta_bw = pmbm_data->delta_bw; - /* - * resctrl_arch_get_config() chooses the mbps/ctrl value to return - * based on is_mba_sc(). For now, reach into the hw_dom. - */ - cur_msr_val = hw_dom_mba->ctrl_val[closid]; + + /* MBA monitor resource doesn't support CDP */ + resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE, &cur_msr_val); /* * For Ctrl groups read data from child monitor groups. -- 2.30.2
| |