Messages in this thread Patch in this message | | | From | Vikas Shivappa <> | Subject | [PATCH 4/6] x86/intel_rdt/mba_sc: Add schemata support | Date | Thu, 29 Mar 2018 15:26:14 -0700 |
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Currently user specifies the maximum memory bandwidth percentage per domain in the "schemata" file. When user updates the schemata, kernel writes the corresponding b/w percentage values to the IA32_MBA_THRTL_MSR.
When MBA is expressed in MegaBytes(MB), the schemata format is changed to have the per package memory b/w in MB instead of being specified in b/w percentage. The b/w percentage values are only <= 100 and the b/w in MB could be upto U32_MAX. We do not write the MSRs when the schemata is updated as that is handled separately after the m/w in MB is converted to b/w in percentage values.
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> --- arch/x86/kernel/cpu/intel_rdt.c | 10 +++++++++- arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 10 ++++++++-- 2 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index 8a32561..8a12d26 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -179,7 +179,7 @@ struct rdt_resource rdt_resources_all[] = { .msr_update = mba_wrmsr, .cache_level = 3, .parse_ctrlval = parse_bw, - .format_str = "%d=%*d", + .format_str = "%d=%*u", .fflags = RFTYPE_RES_MB, }, }; @@ -356,6 +356,14 @@ static u32 delay_bw_map(unsigned long bw, struct rdt_resource *r) { unsigned int i; + /* + * The ctrl_val should not be written when + * MBA is expressed in Megabytes because the Megabyte value + * need to be first converted to delay values that can be + * programmed to the MSR. + */ + WARN_ON(is_mba_MBctrl()); + /* Write the delay values for mba. */ for (i = m->low; i < m->high; i++) wrmsrl(r->msr_base + i, delay_bw_map(d->ctrl_val[i], r)); diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c index 23e1d5c..6372e4f 100644 --- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c +++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c @@ -53,7 +53,8 @@ static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r) return false; } - if (bw < r->membw.min_bw || bw > r->default_ctrl) { + if ((bw < r->membw.min_bw || bw > r->default_ctrl) && + !is_mba_MBctrl()) { rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw, r->membw.min_bw, r->default_ctrl); return false; @@ -194,7 +195,12 @@ static int update_domains(struct rdt_resource *r, int closid) d->ctrl_val[closid] = d->new_ctrl; } } - if (cpumask_empty(cpu_mask)) + + /* + * Avoid writing the control msr with control values when + * MBA is expressed in Megabytes. + */ + if (cpumask_empty(cpu_mask) || is_mba_MBctrl()) goto done; cpu = get_cpu(); /* Update CBM on this cpu if it's in cpu_mask. */ -- 1.9.1
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