Messages in this thread Patch in this message | | | From | James Morse <> | Subject | [PATCH v3 07/21] x86/resctrl: Create mba_sc configuration in the rdt_domain | Date | Thu, 17 Feb 2022 18:20:56 +0000 |
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To support resctrl's MBA software controller, the architecture must provide a second configuration array to hold the mbps_val[] from user-space.
This complicates the interface between the architecture specific code and the filesystem portions of resctrl that will move to /fs/, to allow multiple architectures to support resctrl.
Make the filesystem parts of resctrl create an array for the mba_sc values when is_mba_sc() is set to true. The software controller can be changed to use this, allowing the architecture code to only consider the values configured in hardware.
Signed-off-by: James Morse <james.morse@arm.com> --- Changes since v2: * Split patch in two, the liftime parts are a separate patch. * Added reset in set_mba_sc() now that we can't depend on the lifetime. * Initialise ret in mba_sc_allocate(), * Made mbps_val allocation/freeing symmetric for cpuhp calls. * Removed reference to squashed-out struct. * Preserved kerneldoc for mbps_val.
Changes since v1: * Added missing error handling to mba_sc_domain_allocate() in domain_setup_mon_state() * Added comment about mba_sc_domain_allocate() races * Squashed out struct resctrl_mba_sc * Moved mount time alloc/free calls to set_mba_sc(). * Removed mount check in resctrl_offline_domain() * Reword commit message --- arch/x86/kernel/cpu/resctrl/internal.h | 1 - arch/x86/kernel/cpu/resctrl/rdtgroup.c | 41 ++++++++++++++++++++++++++ include/linux/resctrl.h | 7 +++++ 3 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index e12b55f815bf..a7e2cbce29d5 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -36,7 +36,6 @@ #define MBM_OVERFLOW_INTERVAL 1000 #define MAX_MBA_BW 100u #define MBA_IS_LINEAR 0x4 -#define MBA_MAX_MBPS U32_MAX #define MAX_MBA_BW_AMD 0x800 #define MBM_CNTR_WIDTH_OFFSET_AMD 20 diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 794a84ba9097..e4313f907eb6 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1889,6 +1889,30 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *r) l3_qos_cfg_update(&hw_res->cdp_enabled); } +static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_domain *d) +{ + u32 num_closid = resctrl_arch_get_num_closid(r); + int cpu = cpumask_any(&d->cpu_mask); + int i; + + d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val), + GFP_KERNEL, cpu_to_node(cpu)); + if (!d->mbps_val) + return -ENOMEM; + + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + + return 0; +} + +static void mba_sc_domain_destroy(struct rdt_resource *r, + struct rdt_domain *d) +{ + kfree(d->mbps_val); + d->mbps_val = NULL; +} + /* * Enable or disable the MBA software controller * which helps user specify bandwidth in MBps. @@ -1898,6 +1922,9 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource *r) static int set_mba_sc(bool mba_sc) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + u32 num_closid = resctrl_arch_get_num_closid(r); + struct rdt_domain *d; + int i; if (!is_mbm_enabled() || !is_mba_linear() || mba_sc == is_mba_sc(r)) @@ -1905,6 +1932,11 @@ static int set_mba_sc(bool mba_sc) r->membw.mba_sc = mba_sc; + list_for_each_entry(d, &r->domains, list) { + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + } + return 0; } @@ -3263,6 +3295,9 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d) cancel_delayed_work(&d->cqm_limbo); } + if (is_mba_sc(r)) + mba_sc_domain_destroy(r, d); + domain_destroy_mon_state(d); } @@ -3309,6 +3344,12 @@ int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d) if (err) return err; + err = mba_sc_domain_allocate(r, d); + if (err) { + domain_destroy_mon_state(d); + return err; + } + if (is_mbm_enabled()) { INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL); diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5d283bdd6162..46ab9fb5562e 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -15,6 +15,9 @@ int proc_resctrl_show(struct seq_file *m, #endif +/* max value for struct rdt_domain's mbps_val */ +#define MBA_MAX_MBPS U32_MAX + /** * enum resctrl_conf_type - The type of configuration. * @CDP_NONE: No prioritisation, both code and data are controlled or monitored. @@ -53,6 +56,9 @@ struct resctrl_staged_config { * @cqm_work_cpu: worker CPU for CQM h/w counters * @plr: pseudo-locked region (if any) associated with domain * @staged_config: parsed configuration to be applied + * @mbps_val: When mba_sc is enabled, this holds the array of user + * specified control values for mba_sc in MBps, indexed + * by closid */ struct rdt_domain { struct list_head list; @@ -67,6 +73,7 @@ struct rdt_domain { int cqm_work_cpu; struct pseudo_lock_region *plr; struct resctrl_staged_config staged_config[CDP_NUM_TYPES]; + u32 *mbps_val; }; /** -- 2.30.2
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