From 4d269ed485298e8a09485a664e7b35b370ab4ada Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:09 +0000 Subject: x86/resctrl: Kill off alloc_enabled rdt_resources_all[] used to have extra entries for L2CODE/L2DATA. These were hidden from resctrl by the alloc_enabled value. Now that the L2/L2CODE/L2DATA resources have been merged together, alloc_enabled doesn't mean anything, it always has the same value as alloc_capable which indicates allocation is supported by this resource. Remove alloc_enabled and its helpers. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-2-james.morse@arm.com --- include/linux/resctrl.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 21deb5212bbd..386ab3a41500 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -130,7 +130,6 @@ struct resctrl_schema; /** * struct rdt_resource - attributes of a resctrl resource * @rid: The index of the resource - * @alloc_enabled: Is allocation enabled on this machine * @mon_enabled: Is monitoring enabled for this feature * @alloc_capable: Is allocation available on this machine * @mon_capable: Is monitor feature available on this machine @@ -150,7 +149,6 @@ struct resctrl_schema; */ struct rdt_resource { int rid; - bool alloc_enabled; bool mon_enabled; bool alloc_capable; bool mon_capable; -- cgit v1.2.3 From bab6ee736873becc0216ba5fd159394e272d01b2 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:10 +0000 Subject: x86/resctrl: Merge mon_capable and mon_enabled mon_enabled and mon_capable are always set as a pair by rdt_get_mon_l3_config(). There is no point having two values. Merge them together. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-3-james.morse@arm.com --- include/linux/resctrl.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 386ab3a41500..8180c539800d 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -130,7 +130,6 @@ struct resctrl_schema; /** * struct rdt_resource - attributes of a resctrl resource * @rid: The index of the resource - * @mon_enabled: Is monitoring enabled for this feature * @alloc_capable: Is allocation available on this machine * @mon_capable: Is monitor feature available on this machine * @num_rmid: Number of RMIDs available @@ -149,7 +148,6 @@ struct resctrl_schema; */ struct rdt_resource { int rid; - bool mon_enabled; bool alloc_capable; bool mon_capable; int num_rmid; -- cgit v1.2.3 From 3a7232cdf19e39e7f24c493117b373788b348af2 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:11 +0000 Subject: x86/resctrl: Add domain online callback for resctrl work Because domains are exposed to user-space via resctrl, the filesystem must update its state when CPU hotplug callbacks are triggered. Some of this work is common to any architecture that would support resctrl, but the work is tied up with the architecture code to allocate the memory. Move domain_setup_mon_state(), the monitor subdir creation call and the mbm/limbo workers into a new resctrl_online_domain() call. These bits are not specific to the architecture. Grouping them in one function allows that code to be moved to /fs/ and re-used by another architecture. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-4-james.morse@arm.com --- include/linux/resctrl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 8180c539800d..d512455b4c3a 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -192,5 +192,6 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type); +int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); #endif /* _RESCTRL_H */ -- cgit v1.2.3 From 798fd4b9ac37fec571f55fb8592497b0dd5f7a73 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:13 +0000 Subject: x86/resctrl: Add domain offline callback for resctrl work Because domains are exposed to user-space via resctrl, the filesystem must update its state when CPU hotplug callbacks are triggered. Some of this work is common to any architecture that would support resctrl, but the work is tied up with the architecture code to free the memory. Move the monitor subdir removal and the cancelling of the mbm/limbo works into a new resctrl_offline_domain() call. These bits are not specific to the architecture. Grouping them in one function allows that code to be moved to /fs/ and re-used by another architecture. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-6-james.morse@arm.com --- include/linux/resctrl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index d512455b4c3a..5d283bdd6162 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -193,5 +193,6 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type); int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); +void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); #endif /* _RESCTRL_H */ -- cgit v1.2.3 From 781096d971dfe3c5f9401a300bdb0b148a600584 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:16 +0000 Subject: x86/resctrl: Create mba_sc configuration in the rdt_domain 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. 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 Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-9-james.morse@arm.com --- include/linux/resctrl.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 5d283bdd6162..93dfe553b364 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; }; /** -- cgit v1.2.3 From ff6357bb50023af2a1dc8f113930082c5252c753 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:19 +0000 Subject: x86/resctrl: Allow update_mba_bw() to update controls directly update_mba_bw() calculates a new control value for the MBA resource based on the user provided mbps_val and the current measured bandwidth. Some control values need remapping by delay_bw_map(). It does this by calling wrmsrl() directly. This needs splitting up to be done by an architecture specific helper, so that the remainder can eventually be moved to /fs/. Add resctrl_arch_update_one() to apply one configuration value to the provided resource and domain. This avoids the staging and cross-calling that is only needed with changes made by user-space. delay_bw_map() moves to be part of the arch code, to maintain the 'percentage control' view of MBA resources in resctrl. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-12-james.morse@arm.com --- include/linux/resctrl.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 93dfe553b364..f4c9101df461 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -197,6 +197,14 @@ struct resctrl_schema { /* The number of closid supported by this resource regardless of CDP */ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); + +/* + * Update the ctrl_val and apply this config right now. + * Must be called on one of the domain's CPUs. + */ +int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d, + u32 closid, enum resctrl_conf_type t, u32 cfg_val); + u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type); int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); -- cgit v1.2.3 From fea62d370d7a1ba288d71d0cae7ad47c2a02b839 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:22 +0000 Subject: x86/resctrl: Allow per-rmid arch private storage to be reset To abstract the rmid counters into a helper that returns the number of bytes counted, architecture specific per-rmid state is needed. It needs to be possible to reset this hidden state, as the values may outlive the life of an rmid, or the mount time of the filesystem. mon_event_read() is called with first = true when an rmid is first allocated in mkdir_mondata_subdir(). Add resctrl_arch_reset_rmid() and call it from __mon_event_count()'s rr->first check. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-15-james.morse@arm.com --- include/linux/resctrl.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index f4c9101df461..818456770176 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -32,6 +32,16 @@ enum resctrl_conf_type { #define CDP_NUM_TYPES (CDP_DATA + 1) +/* + * Event IDs, the values match those used to program IA32_QM_EVTSEL before + * reading IA32_QM_CTR on RDT systems. + */ +enum resctrl_event_id { + QOS_L3_OCCUP_EVENT_ID = 0x01, + QOS_L3_MBM_TOTAL_EVENT_ID = 0x02, + QOS_L3_MBM_LOCAL_EVENT_ID = 0x03, +}; + /** * struct resctrl_staged_config - parsed configuration to be applied * @new_ctrl: new ctrl value to be loaded @@ -210,4 +220,17 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); +/** + * resctrl_arch_reset_rmid() - Reset any private state associated with rmid + * and eventid. + * @r: The domain's resource. + * @d: The rmid's domain. + * @rmid: The rmid whose counter values should be reset. + * @eventid: The eventid whose counter values should be reset. + * + * This can be called from any CPU. + */ +void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, + u32 rmid, enum resctrl_event_id eventid); + #endif /* _RESCTRL_H */ -- cgit v1.2.3 From 4d044c521a63b2cd394ea6e3547012032145e47e Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:23 +0000 Subject: x86/resctrl: Abstract __rmid_read() __rmid_read() selects the specified eventid and returns the counter value from the MSR. The error handling is architecture specific, and handled by the callers, rdtgroup_mondata_show() and __mon_event_count(). Error handling should be handled by architecture specific code, as a different architecture may have different requirements. MPAM's counters can report that they are 'not ready', requiring a second read after a short delay. This should be hidden from resctrl. Make __rmid_read() the architecture specific function for reading a counter. Rename it resctrl_arch_rmid_read() and move the error handling into it. A read from a counter that hardware supports but resctrl does not now returns -EINVAL instead of -EIO from the default case in __mon_event_count(). It isn't possible for user-space to see this change as resctrl doesn't expose counters it doesn't support. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-16-james.morse@arm.com --- include/linux/resctrl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 818456770176..efe60dd7fd21 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -219,6 +219,7 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type); int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); +int resctrl_arch_rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *res); /** * resctrl_arch_reset_rmid() - Reset any private state associated with rmid -- cgit v1.2.3 From 8286618aca331bf17323ff3023ca831ac6e4b86f Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:24 +0000 Subject: x86/resctrl: Pass the required parameters into resctrl_arch_rmid_read() resctrl_arch_rmid_read() is intended as the function that an architecture agnostic resctrl filesystem driver can use to read a value in bytes from a hardware register. Currently the function returns the MBM values in chunks directly from hardware. To convert this to bytes, some correction and overflow calculations are needed. These depend on the resource and domain structures. Overflow detection requires the old chunks value. None of this is available to resctrl_arch_rmid_read(). MPAM requires the resource and domain structures to find the MMIO device that holds the registers. Pass the resource and domain to resctrl_arch_rmid_read(). This makes rmid_dirty() too big. Instead merge it with its only caller, and the name is kept as a local variable. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-17-james.morse@arm.com --- include/linux/resctrl.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index efe60dd7fd21..7ccfa0d1bb34 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -219,7 +219,23 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type); int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d); void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); -int resctrl_arch_rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *res); + +/** + * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rmid + * for this resource and domain. + * @r: resource that the counter should be read from. + * @d: domain that the counter should be read from. + * @rmid: rmid of the counter to read. + * @eventid: eventid to read, e.g. L3 occupancy. + * @val: result of the counter read in chunks. + * + * Call from process context on a CPU that belongs to domain @d. + * + * Return: + * 0 on success, or -EIO, -EINVAL etc on error. + */ +int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, + u32 rmid, enum resctrl_event_id eventid, u64 *val); /** * resctrl_arch_reset_rmid() - Reset any private state associated with rmid -- cgit v1.2.3 From ae2328b52962531c2d7c6b531022a3eb2d680f17 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:27 +0000 Subject: x86/resctrl: Rename and change the units of resctrl_cqm_threshold resctrl_cqm_threshold is stored in a hardware specific chunk size, but exposed to user-space as bytes. This means the filesystem parts of resctrl need to know how the hardware counts, to convert the user provided byte value to chunks. The interface between the architecture's resctrl code and the filesystem ought to treat everything as bytes. Change the unit of resctrl_cqm_threshold to bytes. resctrl_arch_rmid_read() still returns its value in chunks, so this needs converting to bytes. As all the users have been touched, rename the variable to resctrl_rmid_realloc_threshold, which describes what the value is for. Neither r->num_rmid nor hw_res->mon_scale are guaranteed to be a power of 2, so the existing code introduces a rounding error from resctrl's theoretical fraction of the cache usage. This behaviour is kept as it ensures the user visible value matches the value read from hardware when the rmid will be reallocated. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-20-james.morse@arm.com --- include/linux/resctrl.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 7ccfa0d1bb34..9995d043650a 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -250,4 +250,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, u32 rmid, enum resctrl_event_id eventid); +extern unsigned int resctrl_rmid_realloc_threshold; + #endif /* _RESCTRL_H */ -- cgit v1.2.3 From d80975e264c8f01518890f3d91ab5bada8fa7f5e Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:28 +0000 Subject: x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data resctrl_rmid_realloc_threshold can be set by user-space. The maximum value is specified by the architecture. Currently max_threshold_occ_write() reads the maximum value from boot_cpu_data.x86_cache_size, which is not portable to another architecture. Add resctrl_rmid_realloc_limit to describe the maximum size in bytes that user-space can set the threshold to. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-21-james.morse@arm.com --- include/linux/resctrl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 9995d043650a..cb857f753322 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -251,5 +251,6 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, u32 rmid, enum resctrl_event_id eventid); extern unsigned int resctrl_rmid_realloc_threshold; +extern unsigned int resctrl_rmid_realloc_limit; #endif /* _RESCTRL_H */ -- cgit v1.2.3 From f7b1843eca6fe295ba0c71fc02a3291954078f2b Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:29 +0000 Subject: x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes resctrl_arch_rmid_read() returns a value in chunks, as read from the hardware. This needs scaling to bytes by mon_scale, as provided by the architecture code. Now that resctrl_arch_rmid_read() performs the overflow and corrections itself, it may as well return a value in bytes directly. This allows the accesses to the architecture specific 'hw' structure to be removed. Move the mon_scale conversion into resctrl_arch_rmid_read(). mbm_bw_count() is updated to calculate bandwidth from bytes. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-22-james.morse@arm.com --- include/linux/resctrl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/resctrl.h') diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index cb857f753322..0cf5b20c6ddf 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -227,7 +227,7 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d); * @d: domain that the counter should be read from. * @rmid: rmid of the counter to read. * @eventid: eventid to read, e.g. L3 occupancy. - * @val: result of the counter read in chunks. + * @val: result of the counter read in bytes. * * Call from process context on a CPU that belongs to domain @d. * -- cgit v1.2.3