Hi Reinette,
On 12/19/2024 5:39 PM, Reinette Chatre wrote:
Hi Babu,
On 12/12/24 12:15 PM, Babu Moger wrote:
Assign/unassign counters on resctrl group creation/deletion. Two counters
are required per group, one for MBM total event and one for MBM local
event.
There are a limited number of counters available for assignment. If these
counters are exhausted, the kernel will display the error message: "Out of
MBM assignable counters". However, it is not necessary to fail the
creation of a group due to assignment failures. Users have the flexibility
to modify the assignments at a later time.
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 81 +++++++++++++++++++++++++-
1 file changed, 79 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a71a8389b649..5acae525881a 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -920,6 +920,25 @@ static int rdtgroup_available_mbm_cntrs_show(struct kernfs_open_file *of,
return ret;
}
+static void mbm_cntr_reset(struct rdt_resource *r)
+{
+ struct rdt_mon_domain *dom;
+
+ /*
+ * Hardware counters will reset after switching the monitor mode.
+ * Reset the architectural state so that reading of hardware
+ * counter is not considered as an overflow in the next update.
+ * Also reset the domain counter bitmap.
+ */
+ if (is_mbm_enabled() && r->mon.mbm_cntr_assignable) {
+ list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+ memset(dom->cntr_cfg, 0,
+ sizeof(*dom->cntr_cfg) * r->mon.num_mbm_cntrs);
+ resctrl_arch_reset_rmid_all(r, dom);
This looks to be missing reset of resctrl monitor state (from get_mbm_state()).
Yes. Will do.
...
static int rdt_get_tree(struct fs_context *fc)
{
struct rdt_fs_context *ctx = rdt_fc2context(fc);
@@ -3023,6 +3082,8 @@ static int rdt_get_tree(struct fs_context *fc)
if (ret < 0)
goto out_info;
+ rdtgroup_assign_cntrs(&rdtgroup_default);
+
ret = mkdir_mondata_all(rdtgroup_default.kn,
&rdtgroup_default, &kn_mondata);
if (ret < 0)
If this mkdir_mondata_all() fails it calls "goto out_mongrp" ...
Sure.
@@ -3058,8 +3119,10 @@ static int rdt_get_tree(struct fs_context *fc)
out_psl:
rdt_pseudo_lock_release();
out_mondata:
- if (resctrl_arch_mon_capable())
+ if (resctrl_arch_mon_capable()) {
kernfs_remove(kn_mondata);
+ rdtgroup_unassign_cntrs(&rdtgroup_default);
+ }
out_mongrp:
if (resctrl_arch_mon_capable())
kernfs_remove(kn_mongrp);
Looks like this will miss counter cleanup on failure of mkdir_mondata_all().
Sure.
@@ -3238,6 +3301,7 @@ static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
head = &rdtgrp->mon.crdtgrp_list;
list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
+ rdtgroup_unassign_cntrs(sentry);
free_rmid(sentry->closid, sentry->mon.rmid);
list_del(&sentry->mon.crdtgrp_list);
@@ -3278,6 +3342,8 @@ static void rmdir_all_sub(void)
cpumask_or(&rdtgroup_default.cpu_mask,
&rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
+ rdtgroup_unassign_cntrs(rdtgrp);
+
free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
kernfs_remove(rdtgrp->kn);
@@ -3309,6 +3375,8 @@ static void rdt_kill_sb(struct super_block *sb)
for_each_alloc_capable_rdt_resource(r)
reset_all_ctrls(r);
rmdir_all_sub();
+ rdtgroup_unassign_cntrs(&rdtgroup_default);
+ mbm_cntr_reset(&rdt_resources_all[RDT_RESOURCE_L3].r_resctrl);
rdt_pseudo_lock_release();
rdtgroup_default.mode = RDT_MODE_SHAREABLE;
schemata_list_destroy();
@@ -3772,6 +3840,8 @@ static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
}
rdtgrp->mon.rmid = ret;
+ rdtgroup_assign_cntrs(rdtgrp);
+
ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
if (ret) {
rdt_last_cmd_puts("kernfs subdir error\n");
Cleanup of assigned counters if mkdir_mondata_all() fails seems to be missing here also.
Sure.
Thanks
Babu
