Introduce the interface to assign MBM events in mbm_cntr_assign mode.
Events can be enabled or disabled by writing to file
/sys/fs/resctrl/info/L3_MON/mbm_assign_control
Format is similar to the list format with addition of opcode for the
assignment operation.
"<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
Format for specific type of groups:
* Default CTRL_MON group:
"//<domain_id><opcode><flags>"
* Non-default CTRL_MON group:
"<CTRL_MON group>//<domain_id><opcode><flags>"
* Child MON group of default CTRL_MON group:
"/<MON group>/<domain_id><opcode><flags>"
* Child MON group of non-default CTRL_MON group:
"<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
Domain_id '*' will apply the flags on all the domains.
Opcode can be one of the following:
= Update the assignment to match the flags
+ Assign a new MBM event without impacting existing assignments.
- Unassign a MBM event from currently assigned events.
Assignment flags can be one of the following:
t MBM total event
l MBM local event
tl Both total and local MBM events
_ None of the MBM events. Valid only with '=' opcode. This flag cannot
be combined with other flags.
Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v9: Fixed handling special case '//0=' and '//".
Removed extra strstr() call.
Added generic failure text when assignment operation fails.
Corrected user documentation format texts.
v8: Moved unassign as the first action during the assign modification.
Assign none "_" takes priority. Cannot be mixed with other flags.
Updated the documentation and .rst file format. htmldoc looks ok.
v7: Simplified the parsing (strsep(&token, "//") in rdtgroup_mbm_assign_control_write().
Added mutex lock in rdtgroup_mbm_assign_control_write() while processing.
Renamed rdtgroup_find_grp to rdtgroup_find_grp_by_name.
Fixed rdtgroup_str_to_mon_state to return error for invalid flags.
Simplified the calls rdtgroup_assign_cntr by merging few functions earlier.
Removed ABMC reference in FS code.
Reinette commented about handling the combination of flags like 'lt_' and '_lt'.
Not sure if we need to change the behaviour here. Processed them sequencially right now.
Users have the liberty to pass the flags. Restricting it might be a problem later.
v6: Added support assign all if domain id is '*'
Fixed the allocation of counter id if it not assigned already.
v5: Interface name changed from mbm_assign_control to mbm_control.
Fixed opcode and flags combination.
'=_" is valid.
"-_" amd "+_" is not valid.
Minor message update.
Renamed the function with prefix - rdtgroup_.
Corrected few documentation mistakes.
Rebase related changes after SNC support.
v4: Added domain specific assignments. Fixed the opcode parsing.
v3: New patch.
Addresses the feedback to provide the global assignment interface.
https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@intel.com/
---
Documentation/arch/x86/resctrl.rst | 116 +++++++++++-
arch/x86/kernel/cpu/resctrl/internal.h | 10 ++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 236 ++++++++++++++++++++++++-
3 files changed, 360 insertions(+), 2 deletions(-)
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 590727bec44b..d0a107d251ec 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -347,7 +347,8 @@ with the following files:
t MBM total event is assigned.
l MBM local event is assigned.
tl Both MBM total and local events are assigned.
- _ None of the MBM events are assigned.
+ _ None of the MBM events are assigned. Only works with opcode '=' for write
+ and cannot be combined with other flags.
Examples:
::
@@ -365,6 +366,119 @@ with the following files:
There are four resctrl groups. All the groups have total and local MBM events
assigned on domain 0 and 1.
+ Assignment state can be updated by writing to the interface.
+
+ Format is similar to the list format with addition of opcode for the
+ assignment operation.
+
+ "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
+
+ Format for each type of groups:
+
+ * Default CTRL_MON group:
+ "//<domain_id><opcode><flags>"
+
+ * Non-default CTRL_MON group:
+ "<CTRL_MON group>//<domain_id><opcode><flags>"
+
+ * Child MON group of default CTRL_MON group:
+ "/<MON group>/<domain_id><opcode><flags>"
+
+ * Child MON group of non-default CTRL_MON group:
+ "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
+
+ Domain_id '*' will apply the flags on all the domains.
+
+ Opcode can be one of the following:
+ ::
+
+ = Update the assignment to match the MBM event.
+ + Assign a new MBM event without impacting existing assignments.
+ - Unassign a MBM event from currently assigned events.
+
+ Examples:
+ Initial group status:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
+ //0=tl;1=tl;
+ /child_default_mon_grp/0=tl;1=tl;
+
+ To update the default group to assign only total MBM event on domain 0:
+ ::
+
+ # echo "//0=t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+
+ Assignment status after the update:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
+ //0=t;1=tl;
+ /child_default_mon_grp/0=tl;1=tl;
+
+ To update the MON group child_default_mon_grp to remove total MBM event on domain 1:
+ ::
+
+ # echo "/child_default_mon_grp/1-t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+
+ Assignment status after the update:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
+ //0=t;1=tl;
+ /child_default_mon_grp/0=tl;1=l;
+
+ To update the MON group non_default_ctrl_mon_grp/child_non_default_mon_grp to unassign
+ both local and total MBM events on domain 1:
+ ::
+
+ # echo "non_default_ctrl_mon_grp/child_non_default_mon_grp/1=_" >
+ /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+
+ Assignment status after the update:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
+ //0=t;1=tl;
+ /child_default_mon_grp/0=tl;1=l;
+
+ To update the default group to add a local MBM event domain 0.
+ ::
+
+ # echo "//0+l" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+
+ Assignment status after the update:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
+ //0=tl;1=tl;
+ /child_default_mon_grp/0=tl;1=l;
+
+ To update the non default CTRL_MON group non_default_ctrl_mon_grp to unassign all the
+ MBM events on all the domains.
+ ::
+
+ # echo "non_default_ctrl_mon_grp//*=_" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+
+ Assignment status after the update:
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=_;1=_;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
+ //0=tl;1=tl;
+ /child_default_mon_grp/0=tl;1=l;
+
"max_threshold_occupancy":
Read/write file provides the largest value (in
bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index b90d8c90b4b6..3ccaea6a2803 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -74,6 +74,16 @@
*/
#define MBM_EVENT_ARRAY_INDEX(_event) ((_event) - 2)
+/*
+ * Assignment flags for mbm_cntr_assign feature
+ */
+enum {
+ ASSIGN_NONE = 0,
+ ASSIGN_TOTAL = BIT(QOS_L3_MBM_TOTAL_EVENT_ID),
+ ASSIGN_LOCAL = BIT(QOS_L3_MBM_LOCAL_EVENT_ID),
+ ASSIGN_INVALID,
+};
+
/**
* cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
* aren't marked nohz_full
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 5cc40eacbe85..9fe419d0c536 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1082,6 +1082,239 @@ static int rdtgroup_mbm_assign_control_show(struct kernfs_open_file *of,
return 0;
}
+static int rdtgroup_str_to_mon_state(char *flag)
+{
+ int i, mon_state = ASSIGN_NONE;
+
+ if (!strlen(flag))
+ return ASSIGN_INVALID;
+
+ for (i = 0; i < strlen(flag); i++) {
+ switch (*(flag + i)) {
+ case 't':
+ mon_state |= ASSIGN_TOTAL;
+ break;
+ case 'l':
+ mon_state |= ASSIGN_LOCAL;
+ break;
+ case '_':
+ return ASSIGN_NONE;
+ default:
+ return ASSIGN_INVALID;
+ }
+ }
+
+ return mon_state;
+}
+
+static struct rdtgroup *rdtgroup_find_grp_by_name(enum rdt_group_type rtype,
+ char *p_grp, char *c_grp)
+{
+ struct rdtgroup *rdtg, *crg;
+
+ if (rtype == RDTCTRL_GROUP && *p_grp == '\0') {
+ return &rdtgroup_default;
+ } else if (rtype == RDTCTRL_GROUP) {
+ list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list)
+ if (!strcmp(p_grp, rdtg->kn->name))
+ return rdtg;
+ } else if (rtype == RDTMON_GROUP) {
+ list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+ if (!strcmp(p_grp, rdtg->kn->name)) {
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (!strcmp(c_grp, crg->kn->name))
+ return crg;
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static int rdtgroup_process_flags(struct rdt_resource *r,
+ enum rdt_group_type rtype,
+ char *p_grp, char *c_grp, char *tok)
+{
+ int op, mon_state, assign_state, unassign_state;
+ char *dom_str, *id_str, *op_str;
+ struct rdt_mon_domain *d;
+ struct rdtgroup *rdtgrp;
+ unsigned long dom_id;
+ int ret, found = 0;
+
+ rdtgrp = rdtgroup_find_grp_by_name(rtype, p_grp, c_grp);
+
+ if (!rdtgrp) {
+ rdt_last_cmd_puts("Not a valid resctrl group\n");
+ return -EINVAL;
+ }
+
+next:
+ if (!tok || tok[0] == '\0')
+ return 0;
+
+ /* Start processing the strings for each domain */
+ dom_str = strim(strsep(&tok, ";"));
+
+ op_str = strpbrk(dom_str, "=+-");
+
+ if (op_str) {
+ op = *op_str;
+ } else {
+ rdt_last_cmd_puts("Missing operation =, +, - character\n");
+ return -EINVAL;
+ }
+
+ id_str = strsep(&dom_str, "=+-");
+
+ /* Check for domain id '*' which means all domains */
+ if (id_str && *id_str == '*') {
+ d = NULL;
+ goto check_state;
+ } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
+ rdt_last_cmd_puts("Missing domain id\n");
+ return -EINVAL;
+ }
+
+ /* Verify if the dom_id is valid */
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ if (d->hdr.id == dom_id) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id);
+ return -EINVAL;
+ }
+
+check_state:
+ mon_state = rdtgroup_str_to_mon_state(dom_str);
+
+ if (mon_state == ASSIGN_INVALID) {
+ rdt_last_cmd_puts("Invalid assign flag\n");
+ goto out_fail;
+ }
+
+ assign_state = 0;
+ unassign_state = 0;
+
+ switch (op) {
+ case '+':
+ if (mon_state == ASSIGN_NONE) {
+ rdt_last_cmd_puts("Invalid assign opcode\n");
+ goto out_fail;
+ }
+ assign_state = mon_state;
+ break;
+ case '-':
+ if (mon_state == ASSIGN_NONE) {
+ rdt_last_cmd_puts("Invalid assign opcode\n");
+ goto out_fail;
+ }
+ unassign_state = mon_state;
+ break;
+ case '=':
+ assign_state = mon_state;
+ unassign_state = (ASSIGN_TOTAL | ASSIGN_LOCAL) & ~assign_state;
+ break;
+ default:
+ break;
+ }
+
+ if (unassign_state & ASSIGN_TOTAL) {
+ ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
+ if (ret)
+ goto out_fail;
+ }
+
+ if (unassign_state & ASSIGN_LOCAL) {
+ ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
+ if (ret)
+ goto out_fail;
+ }
+
+ if (assign_state & ASSIGN_TOTAL) {
+ ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
+ if (ret)
+ goto out_fail;
+ }
+
+ if (assign_state & ASSIGN_LOCAL) {
+ ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
+ if (ret)
+ goto out_fail;
+ }
+
+ goto next;
+
+out_fail:
+ rdt_last_cmd_printf("Assign operation '%c%s' failed on the group %s/%s/\n",
+ op, dom_str, p_grp, c_grp);
+
+ return -EINVAL;
+}
+
+static ssize_t rdtgroup_mbm_assign_control_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ char *token, *cmon_grp, *mon_grp;
+ enum rdt_group_type rtype;
+ int ret;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+
+ buf[nbytes - 1] = '\0';
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ rdt_last_cmd_clear();
+
+ if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
+ rdt_last_cmd_puts("mbm_cntr_assign mode is not enabled\n");
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+ return -EINVAL;
+ }
+
+ while ((token = strsep(&buf, "\n")) != NULL) {
+ /*
+ * The write command follows the following format:
+ * “<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>”
+ * Extract the CTRL_MON group.
+ */
+ cmon_grp = strsep(&token, "/");
+
+ /*
+ * Extract the MON_GROUP.
+ * strsep returns empty string for contiguous delimiters.
+ * Empty mon_grp here means it is a RDTCTRL_GROUP.
+ */
+ mon_grp = strsep(&token, "/");
+
+ if (*mon_grp == '\0')
+ rtype = RDTCTRL_GROUP;
+ else
+ rtype = RDTMON_GROUP;
+
+ ret = rdtgroup_process_flags(r, rtype, cmon_grp, mon_grp, token);
+ if (ret)
+ break;
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return ret ?: nbytes;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL
/*
@@ -2383,9 +2616,10 @@ static struct rftype res_common_files[] = {
},
{
.name = "mbm_assign_control",
- .mode = 0444,
+ .mode = 0644,
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdtgroup_mbm_assign_control_show,
+ .write = rdtgroup_mbm_assign_control_write,
},
{
.name = "mbm_assign_mode",
--
2.34.1
Hi Babu,
On 10/29/24 4:21 PM, Babu Moger wrote:
> Introduce the interface to assign MBM events in mbm_cntr_assign mode.
>
> Events can be enabled or disabled by writing to file
> /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>
> Format is similar to the list format with addition of opcode for the
> assignment operation.
> "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>
> Format for specific type of groups:
>
> * Default CTRL_MON group:
> "//<domain_id><opcode><flags>"
>
> * Non-default CTRL_MON group:
> "<CTRL_MON group>//<domain_id><opcode><flags>"
>
> * Child MON group of default CTRL_MON group:
> "/<MON group>/<domain_id><opcode><flags>"
>
> * Child MON group of non-default CTRL_MON group:
> "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>
> Domain_id '*' will apply the flags on all the domains.
>
> Opcode can be one of the following:
>
> = Update the assignment to match the flags
> + Assign a new MBM event without impacting existing assignments.
> - Unassign a MBM event from currently assigned events.
>
> Assignment flags can be one of the following:
> t MBM total event
> l MBM local event
> tl Both total and local MBM events
> _ None of the MBM events. Valid only with '=' opcode. This flag cannot
> be combined with other flags.
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> v9: Fixed handling special case '//0=' and '//".
> Removed extra strstr() call.
> Added generic failure text when assignment operation fails.
> Corrected user documentation format texts.
>
> v8: Moved unassign as the first action during the assign modification.
> Assign none "_" takes priority. Cannot be mixed with other flags.
> Updated the documentation and .rst file format. htmldoc looks ok.
>
> v7: Simplified the parsing (strsep(&token, "//") in rdtgroup_mbm_assign_control_write().
> Added mutex lock in rdtgroup_mbm_assign_control_write() while processing.
> Renamed rdtgroup_find_grp to rdtgroup_find_grp_by_name.
> Fixed rdtgroup_str_to_mon_state to return error for invalid flags.
> Simplified the calls rdtgroup_assign_cntr by merging few functions earlier.
> Removed ABMC reference in FS code.
> Reinette commented about handling the combination of flags like 'lt_' and '_lt'.
> Not sure if we need to change the behaviour here. Processed them sequencially right now.
> Users have the liberty to pass the flags. Restricting it might be a problem later.
>
> v6: Added support assign all if domain id is '*'
> Fixed the allocation of counter id if it not assigned already.
>
> v5: Interface name changed from mbm_assign_control to mbm_control.
> Fixed opcode and flags combination.
> '=_" is valid.
> "-_" amd "+_" is not valid.
> Minor message update.
> Renamed the function with prefix - rdtgroup_.
> Corrected few documentation mistakes.
> Rebase related changes after SNC support.
>
> v4: Added domain specific assignments. Fixed the opcode parsing.
>
> v3: New patch.
> Addresses the feedback to provide the global assignment interface.
> https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@intel.com/
> ---
> Documentation/arch/x86/resctrl.rst | 116 +++++++++++-
> arch/x86/kernel/cpu/resctrl/internal.h | 10 ++
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 236 ++++++++++++++++++++++++-
> 3 files changed, 360 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index 590727bec44b..d0a107d251ec 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -347,7 +347,8 @@ with the following files:
> t MBM total event is assigned.
> l MBM local event is assigned.
> tl Both MBM total and local events are assigned.
> - _ None of the MBM events are assigned.
> + _ None of the MBM events are assigned. Only works with opcode '=' for write
> + and cannot be combined with other flags.
>
> Examples:
> ::
> @@ -365,6 +366,119 @@ with the following files:
> There are four resctrl groups. All the groups have total and local MBM events
> assigned on domain 0 and 1.
>
> + Assignment state can be updated by writing to the interface.
This is already a bit far from original definition so it may help to be specific what is
meant with "the interface". For example,
Assignment state can be updated by writing to "mbm_assign_control".
> +
> + Format is similar to the list format with addition of opcode for the
> + assignment operation.
> +
> + "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
> +
> + Format for each type of groups:
"Format for each type of group" or "Format of each type of group"?
> +
> + * Default CTRL_MON group:
> + "//<domain_id><opcode><flags>"
> +
> + * Non-default CTRL_MON group:
> + "<CTRL_MON group>//<domain_id><opcode><flags>"
> +
> + * Child MON group of default CTRL_MON group:
> + "/<MON group>/<domain_id><opcode><flags>"
> +
> + * Child MON group of non-default CTRL_MON group:
> + "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
> +
> + Domain_id '*' will apply the flags on all the domains.
"apply the flags on all the domains" -> "apply the flags to all the domains"?
> +
> + Opcode can be one of the following:
> + ::
> +
> + = Update the assignment to match the MBM event.
> + + Assign a new MBM event without impacting existing assignments.
> + - Unassign a MBM event from currently assigned events.
> +
> + Examples:
> + Initial group status:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=tl;1=tl;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
> + //0=tl;1=tl;
> + /child_default_mon_grp/0=tl;1=tl;
> +
> + To update the default group to assign only total MBM event on domain 0:
> + ::
> +
> + # echo "//0=t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +
> + Assignment status after the update:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=tl;1=tl;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
> + //0=t;1=tl;
> + /child_default_mon_grp/0=tl;1=tl;
> +
> + To update the MON group child_default_mon_grp to remove total MBM event on domain 1:
> + ::
> +
> + # echo "/child_default_mon_grp/1-t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +
> + Assignment status after the update:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=tl;1=tl;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
> + //0=t;1=tl;
> + /child_default_mon_grp/0=tl;1=l;
> +
> + To update the MON group non_default_ctrl_mon_grp/child_non_default_mon_grp to unassign
> + both local and total MBM events on domain 1:
> + ::
> +
> + # echo "non_default_ctrl_mon_grp/child_non_default_mon_grp/1=_" >
> + /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +
> + Assignment status after the update:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=tl;1=tl;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
> + //0=t;1=tl;
> + /child_default_mon_grp/0=tl;1=l;
> +
> + To update the default group to add a local MBM event domain 0.
"." -> ":"
> + ::
> +
> + # echo "//0+l" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +
> + Assignment status after the update:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=tl;1=tl;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
> + //0=tl;1=tl;
> + /child_default_mon_grp/0=tl;1=l;
> +
> + To update the non default CTRL_MON group non_default_ctrl_mon_grp to unassign all the
> + MBM events on all the domains.
"." -> ":"
> + ::
> +
> + # echo "non_default_ctrl_mon_grp//*=_" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +
> + Assignment status after the update:
> + ::
> +
> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> + non_default_ctrl_mon_grp//0=_;1=_;
> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
> + //0=tl;1=tl;
> + /child_default_mon_grp/0=tl;1=l;
> +
> "max_threshold_occupancy":
> Read/write file provides the largest value (in
> bytes) at which a previously used LLC_occupancy
> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index b90d8c90b4b6..3ccaea6a2803 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -74,6 +74,16 @@
> */
> #define MBM_EVENT_ARRAY_INDEX(_event) ((_event) - 2)
>
> +/*
> + * Assignment flags for mbm_cntr_assign feature
> + */
"mbm_cntr_assign feature" -> "mbm_cntr_assign mode"?
> +enum {
> + ASSIGN_NONE = 0,
> + ASSIGN_TOTAL = BIT(QOS_L3_MBM_TOTAL_EVENT_ID),
> + ASSIGN_LOCAL = BIT(QOS_L3_MBM_LOCAL_EVENT_ID),
> + ASSIGN_INVALID,
> +};
> +
> /**
> * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
> * aren't marked nohz_full
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 5cc40eacbe85..9fe419d0c536 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1082,6 +1082,239 @@ static int rdtgroup_mbm_assign_control_show(struct kernfs_open_file *of,
> return 0;
> }
>
> +static int rdtgroup_str_to_mon_state(char *flag)
It seems strange to me that a variable used to contain flag bits
is of type int. Why is it not unsigned?
> +{
> + int i, mon_state = ASSIGN_NONE;
> +
> + if (!strlen(flag))
> + return ASSIGN_INVALID;
> +
> + for (i = 0; i < strlen(flag); i++) {
> + switch (*(flag + i)) {
> + case 't':
> + mon_state |= ASSIGN_TOTAL;
> + break;
> + case 'l':
> + mon_state |= ASSIGN_LOCAL;
> + break;
> + case '_':
> + return ASSIGN_NONE;
> + default:
> + return ASSIGN_INVALID;
> + }
> + }
> +
> + return mon_state;
> +}
> +
> +static struct rdtgroup *rdtgroup_find_grp_by_name(enum rdt_group_type rtype,
> + char *p_grp, char *c_grp)
> +{
> + struct rdtgroup *rdtg, *crg;
> +
> + if (rtype == RDTCTRL_GROUP && *p_grp == '\0') {
> + return &rdtgroup_default;
> + } else if (rtype == RDTCTRL_GROUP) {
> + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list)
> + if (!strcmp(p_grp, rdtg->kn->name))
> + return rdtg;
> + } else if (rtype == RDTMON_GROUP) {
> + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
> + if (!strcmp(p_grp, rdtg->kn->name)) {
> + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
> + mon.crdtgrp_list) {
> + if (!strcmp(c_grp, crg->kn->name))
> + return crg;
> + }
> + }
> + }
> + }
> +
> + return NULL;
> +}
> +
> +static int rdtgroup_process_flags(struct rdt_resource *r,
> + enum rdt_group_type rtype,
> + char *p_grp, char *c_grp, char *tok)
> +{
> + int op, mon_state, assign_state, unassign_state;
Same comment about type ... these *_state variables are used to contain
bits representing the flags of the various states. An unsigned variable
seems more appropriate.
> + char *dom_str, *id_str, *op_str;
> + struct rdt_mon_domain *d;
> + struct rdtgroup *rdtgrp;
> + unsigned long dom_id;
> + int ret, found = 0;
Could found be boolean?
> +
> + rdtgrp = rdtgroup_find_grp_by_name(rtype, p_grp, c_grp);
> +
> + if (!rdtgrp) {
> + rdt_last_cmd_puts("Not a valid resctrl group\n");
> + return -EINVAL;
> + }
> +
> +next:
> + if (!tok || tok[0] == '\0')
> + return 0;
> +
> + /* Start processing the strings for each domain */
> + dom_str = strim(strsep(&tok, ";"));
> +
> + op_str = strpbrk(dom_str, "=+-");
> +
> + if (op_str) {
> + op = *op_str;
> + } else {
> + rdt_last_cmd_puts("Missing operation =, +, - character\n");
> + return -EINVAL;
> + }
> +
> + id_str = strsep(&dom_str, "=+-");
> +
> + /* Check for domain id '*' which means all domains */
> + if (id_str && *id_str == '*') {
> + d = NULL;
> + goto check_state;
> + } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
> + rdt_last_cmd_puts("Missing domain id\n");
> + return -EINVAL;
> + }
> +
> + /* Verify if the dom_id is valid */
> + list_for_each_entry(d, &r->mon_domains, hdr.list) {
> + if (d->hdr.id == dom_id) {
> + found = 1;
> + break;
> + }
> + }
> +
> + if (!found) {
> + rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id);
> + return -EINVAL;
> + }
I am missing how "found" is handled on second iteration. If an invalid domain
follows a valid domain it seems like "found" remains set from previous iteration?
> +
> +check_state:
> + mon_state = rdtgroup_str_to_mon_state(dom_str);
> +
> + if (mon_state == ASSIGN_INVALID) {
> + rdt_last_cmd_puts("Invalid assign flag\n");
> + goto out_fail;
> + }
> +
> + assign_state = 0;
> + unassign_state = 0;
> +
> + switch (op) {
> + case '+':
> + if (mon_state == ASSIGN_NONE) {
> + rdt_last_cmd_puts("Invalid assign opcode\n");
> + goto out_fail;
> + }
> + assign_state = mon_state;
> + break;
> + case '-':
> + if (mon_state == ASSIGN_NONE) {
> + rdt_last_cmd_puts("Invalid assign opcode\n");
> + goto out_fail;
> + }
> + unassign_state = mon_state;
> + break;
> + case '=':
> + assign_state = mon_state;
> + unassign_state = (ASSIGN_TOTAL | ASSIGN_LOCAL) & ~assign_state;
> + break;
> + default:
> + break;
> + }
> +
> + if (unassign_state & ASSIGN_TOTAL) {
> + ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
> + if (ret)
> + goto out_fail;
> + }
> +
> + if (unassign_state & ASSIGN_LOCAL) {
> + ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
> + if (ret)
> + goto out_fail;
> + }
> +
> + if (assign_state & ASSIGN_TOTAL) {
> + ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
> + if (ret)
> + goto out_fail;
> + }
> +
> + if (assign_state & ASSIGN_LOCAL) {
> + ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
> + if (ret)
> + goto out_fail;
> + }
> +
> + goto next;
> +
> +out_fail:
> + rdt_last_cmd_printf("Assign operation '%c%s' failed on the group %s/%s/\n",
> + op, dom_str, p_grp, c_grp);
> +
Can the domain id be printed also? This seems only piece missing to understand what failed.
> + return -EINVAL;
> +}
> +
> +static ssize_t rdtgroup_mbm_assign_control_write(struct kernfs_open_file *of,
> + char *buf, size_t nbytes, loff_t off)
> +{
> + struct rdt_resource *r = of->kn->parent->priv;
> + char *token, *cmon_grp, *mon_grp;
> + enum rdt_group_type rtype;
> + int ret;
> +
> + /* Valid input requires a trailing newline */
> + if (nbytes == 0 || buf[nbytes - 1] != '\n')
> + return -EINVAL;
> +
> + buf[nbytes - 1] = '\0';
> +
> + cpus_read_lock();
> + mutex_lock(&rdtgroup_mutex);
> +
> + rdt_last_cmd_clear();
> +
> + if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
> + rdt_last_cmd_puts("mbm_cntr_assign mode is not enabled\n");
> + mutex_unlock(&rdtgroup_mutex);
> + cpus_read_unlock();
> + return -EINVAL;
> + }
> +
> + while ((token = strsep(&buf, "\n")) != NULL) {
> + /*
> + * The write command follows the following format:
> + * “<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>”
> + * Extract the CTRL_MON group.
> + */
> + cmon_grp = strsep(&token, "/");
> +
> + /*
> + * Extract the MON_GROUP.
> + * strsep returns empty string for contiguous delimiters.
> + * Empty mon_grp here means it is a RDTCTRL_GROUP.
> + */
> + mon_grp = strsep(&token, "/");
> +
> + if (*mon_grp == '\0')
> + rtype = RDTCTRL_GROUP;
> + else
> + rtype = RDTMON_GROUP;
> +
> + ret = rdtgroup_process_flags(r, rtype, cmon_grp, mon_grp, token);
> + if (ret)
> + break;
> + }
> +
> + mutex_unlock(&rdtgroup_mutex);
> + cpus_read_unlock();
> +
> + return ret ?: nbytes;
> +}
> +
> #ifdef CONFIG_PROC_CPU_RESCTRL
>
> /*
> @@ -2383,9 +2616,10 @@ static struct rftype res_common_files[] = {
> },
> {
> .name = "mbm_assign_control",
> - .mode = 0444,
> + .mode = 0644,
> .kf_ops = &rdtgroup_kf_single_ops,
> .seq_show = rdtgroup_mbm_assign_control_show,
> + .write = rdtgroup_mbm_assign_control_write,
> },
> {
> .name = "mbm_assign_mode",
Reinette
Hi Reinette,
On 11/18/24 15:51, Reinette Chatre wrote:
> Hi Babu,
>
> On 10/29/24 4:21 PM, Babu Moger wrote:
>> Introduce the interface to assign MBM events in mbm_cntr_assign mode.
>>
>> Events can be enabled or disabled by writing to file
>> /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>>
>> Format is similar to the list format with addition of opcode for the
>> assignment operation.
>> "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>>
>> Format for specific type of groups:
>>
>> * Default CTRL_MON group:
>> "//<domain_id><opcode><flags>"
>>
>> * Non-default CTRL_MON group:
>> "<CTRL_MON group>//<domain_id><opcode><flags>"
>>
>> * Child MON group of default CTRL_MON group:
>> "/<MON group>/<domain_id><opcode><flags>"
>>
>> * Child MON group of non-default CTRL_MON group:
>> "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>>
>> Domain_id '*' will apply the flags on all the domains.
>>
>> Opcode can be one of the following:
>>
>> = Update the assignment to match the flags
>> + Assign a new MBM event without impacting existing assignments.
>> - Unassign a MBM event from currently assigned events.
>>
>> Assignment flags can be one of the following:
>> t MBM total event
>> l MBM local event
>> tl Both total and local MBM events
>> _ None of the MBM events. Valid only with '=' opcode. This flag cannot
>> be combined with other flags.
>>
>> Signed-off-by: Babu Moger <babu.moger@amd.com>
>> ---
>> v9: Fixed handling special case '//0=' and '//".
>> Removed extra strstr() call.
>> Added generic failure text when assignment operation fails.
>> Corrected user documentation format texts.
>>
>> v8: Moved unassign as the first action during the assign modification.
>> Assign none "_" takes priority. Cannot be mixed with other flags.
>> Updated the documentation and .rst file format. htmldoc looks ok.
>>
>> v7: Simplified the parsing (strsep(&token, "//") in rdtgroup_mbm_assign_control_write().
>> Added mutex lock in rdtgroup_mbm_assign_control_write() while processing.
>> Renamed rdtgroup_find_grp to rdtgroup_find_grp_by_name.
>> Fixed rdtgroup_str_to_mon_state to return error for invalid flags.
>> Simplified the calls rdtgroup_assign_cntr by merging few functions earlier.
>> Removed ABMC reference in FS code.
>> Reinette commented about handling the combination of flags like 'lt_' and '_lt'.
>> Not sure if we need to change the behaviour here. Processed them sequencially right now.
>> Users have the liberty to pass the flags. Restricting it might be a problem later.
>>
>> v6: Added support assign all if domain id is '*'
>> Fixed the allocation of counter id if it not assigned already.
>>
>> v5: Interface name changed from mbm_assign_control to mbm_control.
>> Fixed opcode and flags combination.
>> '=_" is valid.
>> "-_" amd "+_" is not valid.
>> Minor message update.
>> Renamed the function with prefix - rdtgroup_.
>> Corrected few documentation mistakes.
>> Rebase related changes after SNC support.
>>
>> v4: Added domain specific assignments. Fixed the opcode parsing.
>>
>> v3: New patch.
>> Addresses the feedback to provide the global assignment interface.
>> https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@intel.com/
>> ---
>> Documentation/arch/x86/resctrl.rst | 116 +++++++++++-
>> arch/x86/kernel/cpu/resctrl/internal.h | 10 ++
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 236 ++++++++++++++++++++++++-
>> 3 files changed, 360 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
>> index 590727bec44b..d0a107d251ec 100644
>> --- a/Documentation/arch/x86/resctrl.rst
>> +++ b/Documentation/arch/x86/resctrl.rst
>> @@ -347,7 +347,8 @@ with the following files:
>> t MBM total event is assigned.
>> l MBM local event is assigned.
>> tl Both MBM total and local events are assigned.
>> - _ None of the MBM events are assigned.
>> + _ None of the MBM events are assigned. Only works with opcode '=' for write
>> + and cannot be combined with other flags.
>>
>> Examples:
>> ::
>> @@ -365,6 +366,119 @@ with the following files:
>> There are four resctrl groups. All the groups have total and local MBM events
>> assigned on domain 0 and 1.
>>
>> + Assignment state can be updated by writing to the interface.
>
> This is already a bit far from original definition so it may help to be specific what is
> meant with "the interface". For example,
>
> Assignment state can be updated by writing to "mbm_assign_control".
Sure.
>
>> +
>> + Format is similar to the list format with addition of opcode for the
>> + assignment operation.
>> +
>> + "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>> +
>> + Format for each type of groups:
>
> "Format for each type of group" or "Format of each type of group"?
Sure.
>
>> +
>> + * Default CTRL_MON group:
>> + "//<domain_id><opcode><flags>"
>> +
>> + * Non-default CTRL_MON group:
>> + "<CTRL_MON group>//<domain_id><opcode><flags>"
>> +
>> + * Child MON group of default CTRL_MON group:
>> + "/<MON group>/<domain_id><opcode><flags>"
>> +
>> + * Child MON group of non-default CTRL_MON group:
>> + "<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>"
>> +
>> + Domain_id '*' will apply the flags on all the domains.
>
> "apply the flags on all the domains" -> "apply the flags to all the domains"?
Sure.
>
>> +
>> + Opcode can be one of the following:
>> + ::
>> +
>> + = Update the assignment to match the MBM event.
>> + + Assign a new MBM event without impacting existing assignments.
>> + - Unassign a MBM event from currently assigned events.
>> +
>> + Examples:
>> + Initial group status:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=tl;1=tl;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
>> + //0=tl;1=tl;
>> + /child_default_mon_grp/0=tl;1=tl;
>> +
>> + To update the default group to assign only total MBM event on domain 0:
>> + ::
>> +
>> + # echo "//0=t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> +
>> + Assignment status after the update:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=tl;1=tl;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
>> + //0=t;1=tl;
>> + /child_default_mon_grp/0=tl;1=tl;
>> +
>> + To update the MON group child_default_mon_grp to remove total MBM event on domain 1:
>> + ::
>> +
>> + # echo "/child_default_mon_grp/1-t" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> +
>> + Assignment status after the update:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=tl;1=tl;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
>> + //0=t;1=tl;
>> + /child_default_mon_grp/0=tl;1=l;
>> +
>> + To update the MON group non_default_ctrl_mon_grp/child_non_default_mon_grp to unassign
>> + both local and total MBM events on domain 1:
>> + ::
>> +
>> + # echo "non_default_ctrl_mon_grp/child_non_default_mon_grp/1=_" >
>> + /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> +
>> + Assignment status after the update:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=tl;1=tl;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
>> + //0=t;1=tl;
>> + /child_default_mon_grp/0=tl;1=l;
>> +
>> + To update the default group to add a local MBM event domain 0.
>
> "." -> ":"
Sure.
>
>> + ::
>> +
>> + # echo "//0+l" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> +
>> + Assignment status after the update:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=tl;1=tl;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
>> + //0=tl;1=tl;
>> + /child_default_mon_grp/0=tl;1=l;
>> +
>> + To update the non default CTRL_MON group non_default_ctrl_mon_grp to unassign all the
>> + MBM events on all the domains.
>
> "." -> ":"
Sure.
>
>> + ::
>> +
>> + # echo "non_default_ctrl_mon_grp//*=_" > /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> +
>> + Assignment status after the update:
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>> + non_default_ctrl_mon_grp//0=_;1=_;
>> + non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=_;
>> + //0=tl;1=tl;
>> + /child_default_mon_grp/0=tl;1=l;
>> +
>> "max_threshold_occupancy":
>> Read/write file provides the largest value (in
>> bytes) at which a previously used LLC_occupancy
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
>> index b90d8c90b4b6..3ccaea6a2803 100644
>> --- a/arch/x86/kernel/cpu/resctrl/internal.h
>> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
>> @@ -74,6 +74,16 @@
>> */
>> #define MBM_EVENT_ARRAY_INDEX(_event) ((_event) - 2)
>>
>> +/*
>> + * Assignment flags for mbm_cntr_assign feature
>> + */
>
> "mbm_cntr_assign feature" -> "mbm_cntr_assign mode"?
Sure.
>
>> +enum {
>> + ASSIGN_NONE = 0,
>> + ASSIGN_TOTAL = BIT(QOS_L3_MBM_TOTAL_EVENT_ID),
>> + ASSIGN_LOCAL = BIT(QOS_L3_MBM_LOCAL_EVENT_ID),
>> + ASSIGN_INVALID,
>> +};
>> +
>> /**
>> * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
>> * aren't marked nohz_full
>> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> index 5cc40eacbe85..9fe419d0c536 100644
>> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
>> @@ -1082,6 +1082,239 @@ static int rdtgroup_mbm_assign_control_show(struct kernfs_open_file *of,
>> return 0;
>> }
>>
>> +static int rdtgroup_str_to_mon_state(char *flag)
>
> It seems strange to me that a variable used to contain flag bits
> is of type int. Why is it not unsigned?
Will change it to "unsigned int"
>
>> +{
>> + int i, mon_state = ASSIGN_NONE;
>> +
>> + if (!strlen(flag))
>> + return ASSIGN_INVALID;
>> +
>> + for (i = 0; i < strlen(flag); i++) {
>> + switch (*(flag + i)) {
>> + case 't':
>> + mon_state |= ASSIGN_TOTAL;
>> + break;
>> + case 'l':
>> + mon_state |= ASSIGN_LOCAL;
>> + break;
>> + case '_':
>> + return ASSIGN_NONE;
>> + default:
>> + return ASSIGN_INVALID;
>> + }
>> + }
>> +
>> + return mon_state;
>> +}
>> +
>> +static struct rdtgroup *rdtgroup_find_grp_by_name(enum rdt_group_type rtype,
>> + char *p_grp, char *c_grp)
>> +{
>> + struct rdtgroup *rdtg, *crg;
>> +
>> + if (rtype == RDTCTRL_GROUP && *p_grp == '\0') {
>> + return &rdtgroup_default;
>> + } else if (rtype == RDTCTRL_GROUP) {
>> + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list)
>> + if (!strcmp(p_grp, rdtg->kn->name))
>> + return rdtg;
>> + } else if (rtype == RDTMON_GROUP) {
>> + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
>> + if (!strcmp(p_grp, rdtg->kn->name)) {
>> + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
>> + mon.crdtgrp_list) {
>> + if (!strcmp(c_grp, crg->kn->name))
>> + return crg;
>> + }
>> + }
>> + }
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +static int rdtgroup_process_flags(struct rdt_resource *r,
>> + enum rdt_group_type rtype,
>> + char *p_grp, char *c_grp, char *tok)
>> +{
>> + int op, mon_state, assign_state, unassign_state;
>
> Same comment about type ... these *_state variables are used to contain
> bits representing the flags of the various states. An unsigned variable
> seems more appropriate.
Will change into unsigned int.
>
>> + char *dom_str, *id_str, *op_str;
>> + struct rdt_mon_domain *d;
>> + struct rdtgroup *rdtgrp;
>> + unsigned long dom_id;
>> + int ret, found = 0;
>
> Could found be boolean?
Sure.
>
>> +
>> + rdtgrp = rdtgroup_find_grp_by_name(rtype, p_grp, c_grp);
>> +
>> + if (!rdtgrp) {
>> + rdt_last_cmd_puts("Not a valid resctrl group\n");
>> + return -EINVAL;
>> + }
>> +
>> +next:
>> + if (!tok || tok[0] == '\0')
>> + return 0;
>> +
>> + /* Start processing the strings for each domain */
>> + dom_str = strim(strsep(&tok, ";"));
>> +
>> + op_str = strpbrk(dom_str, "=+-");
>> +
>> + if (op_str) {
>> + op = *op_str;
>> + } else {
>> + rdt_last_cmd_puts("Missing operation =, +, - character\n");
>> + return -EINVAL;
>> + }
>> +
>> + id_str = strsep(&dom_str, "=+-");
>> +
>> + /* Check for domain id '*' which means all domains */
>> + if (id_str && *id_str == '*') {
>> + d = NULL;
>> + goto check_state;
>> + } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
>> + rdt_last_cmd_puts("Missing domain id\n");
>> + return -EINVAL;
>> + }
>> +
>> + /* Verify if the dom_id is valid */
>> + list_for_each_entry(d, &r->mon_domains, hdr.list) {
>> + if (d->hdr.id == dom_id) {
>> + found = 1;
>> + break;
>> + }
>> + }
>> +
>> + if (!found) {
>> + rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id);
>> + return -EINVAL;
>> + }
>
> I am missing how "found" is handled on second iteration. If an invalid domain
> follows a valid domain it seems like "found" remains set from previous iteration?
Yes. It should be reset. Good catch !
>
>> +
>> +check_state:
>> + mon_state = rdtgroup_str_to_mon_state(dom_str);
>> +
>> + if (mon_state == ASSIGN_INVALID) {
>> + rdt_last_cmd_puts("Invalid assign flag\n");
>> + goto out_fail;
>> + }
>> +
>> + assign_state = 0;
>> + unassign_state = 0;
>> +
>> + switch (op) {
>> + case '+':
>> + if (mon_state == ASSIGN_NONE) {
>> + rdt_last_cmd_puts("Invalid assign opcode\n");
>> + goto out_fail;
>> + }
>> + assign_state = mon_state;
>> + break;
>> + case '-':
>> + if (mon_state == ASSIGN_NONE) {
>> + rdt_last_cmd_puts("Invalid assign opcode\n");
>> + goto out_fail;
>> + }
>> + unassign_state = mon_state;
>> + break;
>> + case '=':
>> + assign_state = mon_state;
>> + unassign_state = (ASSIGN_TOTAL | ASSIGN_LOCAL) & ~assign_state;
>> + break;
>> + default:
>> + break;
>> + }
>> +
>> + if (unassign_state & ASSIGN_TOTAL) {
>> + ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
>> + if (ret)
>> + goto out_fail;
>> + }
>> +
>> + if (unassign_state & ASSIGN_LOCAL) {
>> + ret = rdtgroup_unassign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
>> + if (ret)
>> + goto out_fail;
>> + }
>> +
>> + if (assign_state & ASSIGN_TOTAL) {
>> + ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID);
>> + if (ret)
>> + goto out_fail;
>> + }
>> +
>> + if (assign_state & ASSIGN_LOCAL) {
>> + ret = rdtgroup_assign_cntr_event(r, rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID);
>> + if (ret)
>> + goto out_fail;
>> + }
>> +
>> + goto next;
>> +
>> +out_fail:
>> + rdt_last_cmd_printf("Assign operation '%c%s' failed on the group %s/%s/\n",
>> + op, dom_str, p_grp, c_grp);
>> +
>
> Can the domain id be printed also? This seems only piece missing to understand what failed.
Sure. Need to add a check if it is '*' or actual domain id.
Will do.
>
>> + return -EINVAL;
>> +}
>> +
>> +static ssize_t rdtgroup_mbm_assign_control_write(struct kernfs_open_file *of,
>> + char *buf, size_t nbytes, loff_t off)
>> +{
>> + struct rdt_resource *r = of->kn->parent->priv;
>> + char *token, *cmon_grp, *mon_grp;
>> + enum rdt_group_type rtype;
>> + int ret;
>> +
>> + /* Valid input requires a trailing newline */
>> + if (nbytes == 0 || buf[nbytes - 1] != '\n')
>> + return -EINVAL;
>> +
>> + buf[nbytes - 1] = '\0';
>> +
>> + cpus_read_lock();
>> + mutex_lock(&rdtgroup_mutex);
>> +
>> + rdt_last_cmd_clear();
>> +
>> + if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
>> + rdt_last_cmd_puts("mbm_cntr_assign mode is not enabled\n");
>> + mutex_unlock(&rdtgroup_mutex);
>> + cpus_read_unlock();
>> + return -EINVAL;
>> + }
>> +
>> + while ((token = strsep(&buf, "\n")) != NULL) {
>> + /*
>> + * The write command follows the following format:
>> + * “<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>”
>> + * Extract the CTRL_MON group.
>> + */
>> + cmon_grp = strsep(&token, "/");
>> +
>> + /*
>> + * Extract the MON_GROUP.
>> + * strsep returns empty string for contiguous delimiters.
>> + * Empty mon_grp here means it is a RDTCTRL_GROUP.
>> + */
>> + mon_grp = strsep(&token, "/");
>> +
>> + if (*mon_grp == '\0')
>> + rtype = RDTCTRL_GROUP;
>> + else
>> + rtype = RDTMON_GROUP;
>> +
>> + ret = rdtgroup_process_flags(r, rtype, cmon_grp, mon_grp, token);
>> + if (ret)
>> + break;
>> + }
>> +
>> + mutex_unlock(&rdtgroup_mutex);
>> + cpus_read_unlock();
>> +
>> + return ret ?: nbytes;
>> +}
>> +
>> #ifdef CONFIG_PROC_CPU_RESCTRL
>>
>> /*
>> @@ -2383,9 +2616,10 @@ static struct rftype res_common_files[] = {
>> },
>> {
>> .name = "mbm_assign_control",
>> - .mode = 0444,
>> + .mode = 0644,
>> .kf_ops = &rdtgroup_kf_single_ops,
>> .seq_show = rdtgroup_mbm_assign_control_show,
>> + .write = rdtgroup_mbm_assign_control_write,
>> },
>> {
>> .name = "mbm_assign_mode",
>
> Reinette
>
>
--
Thanks
Babu Moger
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