* [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem.
@ 2025-05-30 18:20 Qinyun Tan
2025-05-30 18:20 ` [PATCH V6 1/1] " Qinyun Tan
2025-06-09 17:01 ` [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate " Reinette Chatre
0 siblings, 2 replies; 4+ messages in thread
From: Qinyun Tan @ 2025-05-30 18:20 UTC (permalink / raw)
To: Tony Luck; +Cc: H . Peter Anvin, linux-kernel, x86, Reinette Chatre, Qinyun Tan
V6:
- Modify subject tag "x86/resctrl:" -> "x86,fs/resctrl:"
V5:
- Modify the commit log format again. I am truly grateful to Reinette
for her thoughtful guidance :).
V4:
- Add the tested by and reviewed by tags.
- Modify the commit log format.
V3:
- According to Reinette suggestion, modify the commit log description to
make it easier for readers to understand
V2:
- Keep sanity checks in the __mon_event_count to ensure execution occurs
exclusively on CPUs sharing the same L3 cache cluster
- When reading the top level event, obtain a CPU within hdr.cpu_mask.
Then use the cacheinfo shared_cpu_map of this CPU instead of using
hdr.cpu_mask directly
- Adjust code formatting and commit log descriptions.
In the resctrl subsystem's Sub-NUMA Cluster (SNC) mode, the rdt_mon_domain
structure representing a NUMA node relies on the cacheinfo interface
(rdt_mon_domain::ci) to store L3 cache information (e.g., shared_cpu_map)
for monitoring. The L3 cache information of a SNC NUMA node determines
which domains are summed for the "top level" L3-scoped events.
rdt_mon_domain::ci is initialized using the first online CPU of a NUMA
node. When this CPU goes offline, its shared_cpu_map is cleared to contain
only the offline CPU itself. Subsequently, attempting to read counters
via smp_call_on_cpu(offline_cpu) fails (and error ignored), returning
zero values for "top-level events" without any error indication.
Replace the cacheinfo references in struct rdt_mon_domain and struct
rmid_read with the cacheinfo ID (a unique identifier for the L3 cache).
rdt_domain_hdr::cpu_mask contains the online CPUs associated with that
domain. When reading "top-level events", select a CPU from
rdt_domain_hdr::cpu_mask and utilize its L3 shared_cpu_map to determine
valid CPUs for reading RMID counter via the MSR interface.
Considering all CPUs associated with the L3 cache improves the chances
of picking a housekeeping CPU on which the counter reading work can be
queued, avoiding an unnecessary IPI.
Qinyun Tan (1):
x86/resctrl: Remove unappropriate references to cacheinfo in the
resctrl subsystem.
arch/x86/kernel/cpu/resctrl/core.c | 6 ++++--
fs/resctrl/ctrlmondata.c | 13 +++++++++----
fs/resctrl/internal.h | 4 ++--
fs/resctrl/monitor.c | 6 ++++--
fs/resctrl/rdtgroup.c | 6 +++---
include/linux/resctrl.h | 4 ++--
6 files changed, 24 insertions(+), 15 deletions(-)
--
2.43.5
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH V6 1/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem. 2025-05-30 18:20 [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem Qinyun Tan @ 2025-05-30 18:20 ` Qinyun Tan 2025-06-16 19:51 ` [tip: x86/urgent] x86,fs/resctrl: Remove inappropriate " tip-bot2 for Qinyun Tan 2025-06-09 17:01 ` [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate " Reinette Chatre 1 sibling, 1 reply; 4+ messages in thread From: Qinyun Tan @ 2025-05-30 18:20 UTC (permalink / raw) To: Tony Luck; +Cc: H . Peter Anvin, linux-kernel, x86, Reinette Chatre, Qinyun Tan In the resctrl subsystem's Sub-NUMA Cluster (SNC) mode, the rdt_mon_domain structure representing a NUMA node relies on the cacheinfo interface (rdt_mon_domain::ci) to store L3 cache information (e.g., shared_cpu_map) for monitoring. The L3 cache information of a SNC NUMA node determines which domains are summed for the "top level" L3-scoped events. rdt_mon_domain::ci is initialized using the first online CPU of a NUMA node. When this CPU goes offline, its shared_cpu_map is cleared to contain only the offline CPU itself. Subsequently, attempting to read counters via smp_call_on_cpu(offline_cpu) fails (and error ignored), returning zero values for "top-level events" without any error indication. Replace the cacheinfo references in struct rdt_mon_domain and struct rmid_read with the cacheinfo ID (a unique identifier for the L3 cache). rdt_domain_hdr::cpu_mask contains the online CPUs associated with that domain. When reading "top-level events", select a CPU from rdt_domain_hdr::cpu_mask and utilize its L3 shared_cpu_map to determine valid CPUs for reading RMID counter via the MSR interface. Considering all CPUs associated with the L3 cache improves the chances of picking a housekeeping CPU on which the counter reading work can be queued, avoiding an unnecessary IPI. Fixes: 328ea68874642 ("x86/resctrl: Prepare for new Sub-NUMA Cluster (SNC) monitor files") Signed-off-by: Qinyun Tan <qinyuntan@linux.alibaba.com> Tested-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> --- arch/x86/kernel/cpu/resctrl/core.c | 6 ++++-- fs/resctrl/ctrlmondata.c | 13 +++++++++---- fs/resctrl/internal.h | 4 ++-- fs/resctrl/monitor.c | 6 ++++-- fs/resctrl/rdtgroup.c | 6 +++--- include/linux/resctrl.h | 4 ++-- 6 files changed, 24 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 7109cbfcad4fd..187d527ef73b6 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -498,6 +498,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) struct rdt_hw_mon_domain *hw_dom; struct rdt_domain_hdr *hdr; struct rdt_mon_domain *d; + struct cacheinfo *ci; int err; lockdep_assert_held(&domain_list_lock); @@ -525,12 +526,13 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) d = &hw_dom->d_resctrl; d->hdr.id = id; d->hdr.type = RESCTRL_MON_DOMAIN; - d->ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); - if (!d->ci) { + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci) { pr_warn_once("Can't find L3 cache for CPU:%d resource %s\n", cpu, r->name); mon_domain_free(hw_dom); return; } + d->ci_id = ci->id; cpumask_set_cpu(cpu, &d->hdr.cpu_mask); arch_mon_domain_online(r, d); diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index 6ed2dfd4dbbd9..d98e0d2de09fd 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -594,9 +594,10 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) struct rmid_read rr = {0}; struct rdt_mon_domain *d; struct rdtgroup *rdtgrp; + int domid, cpu, ret = 0; struct rdt_resource *r; + struct cacheinfo *ci; struct mon_data *md; - int domid, ret = 0; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { @@ -623,10 +624,14 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) * one that matches this cache id. */ list_for_each_entry(d, &r->mon_domains, hdr.list) { - if (d->ci->id == domid) { - rr.ci = d->ci; + if (d->ci_id == domid) { + rr.ci_id = d->ci_id; + cpu = cpumask_any(&d->hdr.cpu_mask); + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci) + continue; mon_event_read(&rr, r, NULL, rdtgrp, - &d->ci->shared_cpu_map, evtid, false); + &ci->shared_cpu_map, evtid, false); goto checkresult; } } diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index 9a8cf6f11151d..0a1eedba2b03a 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -98,7 +98,7 @@ struct mon_data { * domains in @r sharing L3 @ci.id * @evtid: Which monitor event to read. * @first: Initialize MBM counter when true. - * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains. + * @ci_id: Cacheinfo id for L3. Only set when @d is NULL. Used when summing domains. * @err: Error encountered when reading counter. * @val: Returned value of event counter. If @rgrp is a parent resource group, * @val includes the sum of event counts from its child resource groups. @@ -112,7 +112,7 @@ struct rmid_read { struct rdt_mon_domain *d; enum resctrl_event_id evtid; bool first; - struct cacheinfo *ci; + unsigned int ci_id; int err; u64 val; void *arch_mon_ctx; diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index bde2801289d35..f5637855c3aca 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -361,6 +361,7 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) { int cpu = smp_processor_id(); struct rdt_mon_domain *d; + struct cacheinfo *ci; struct mbm_state *m; int err, ret; u64 tval = 0; @@ -388,7 +389,8 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) } /* Summing domains that share a cache, must be on a CPU for that cache. */ - if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map)) + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci || ci->id != rr->ci_id) return -EINVAL; /* @@ -400,7 +402,7 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) */ ret = -EINVAL; list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { - if (d->ci->id != rr->ci->id) + if (d->ci_id != rr->ci_id) continue; err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, rr->evtid, &tval, rr->arch_mon_ctx); diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index cc37f58b47dd7..74b25bbb9872c 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -3034,7 +3034,7 @@ static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, char name[32]; snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci_id : d->hdr.id); if (snc_mode) sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id); @@ -3059,7 +3059,7 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, return -EPERM; list_for_each_entry(mevt, &r->evt_list, list) { - domid = do_sum ? d->ci->id : d->hdr.id; + domid = do_sum ? d->ci_id : d->hdr.id; priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum); if (WARN_ON_ONCE(!priv)) return -EINVAL; @@ -3087,7 +3087,7 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, lockdep_assert_held(&rdtgroup_mutex); snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci_id : d->hdr.id); kn = kernfs_find_and_get(parent_kn, name); if (kn) { /* diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 9ba771f2ddead..6fb4894b8cfd1 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -159,7 +159,7 @@ struct rdt_ctrl_domain { /** * struct rdt_mon_domain - group of CPUs sharing a resctrl monitor resource * @hdr: common header for different domain types - * @ci: cache info for this domain + * @ci_id: cache info id for this domain * @rmid_busy_llc: bitmap of which limbo RMIDs are above threshold * @mbm_total: saved state for MBM total bandwidth * @mbm_local: saved state for MBM local bandwidth @@ -170,7 +170,7 @@ struct rdt_ctrl_domain { */ struct rdt_mon_domain { struct rdt_domain_hdr hdr; - struct cacheinfo *ci; + unsigned int ci_id; unsigned long *rmid_busy_llc; struct mbm_state *mbm_total; struct mbm_state *mbm_local; -- 2.43.5 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip: x86/urgent] x86,fs/resctrl: Remove inappropriate references to cacheinfo in the resctrl subsystem 2025-05-30 18:20 ` [PATCH V6 1/1] " Qinyun Tan @ 2025-06-16 19:51 ` tip-bot2 for Qinyun Tan 0 siblings, 0 replies; 4+ messages in thread From: tip-bot2 for Qinyun Tan @ 2025-06-16 19:51 UTC (permalink / raw) To: linux-tip-commits Cc: Qinyun Tan, Borislav Petkov (AMD), Reinette Chatre, Tony Luck, x86, linux-kernel The following commit has been merged into the x86/urgent branch of tip: Commit-ID: 594902c986e269660302f09df9ec4bf1cf017b77 Gitweb: https://git.kernel.org/tip/594902c986e269660302f09df9ec4bf1cf017b77 Author: Qinyun Tan <qinyuntan@linux.alibaba.com> AuthorDate: Sat, 31 May 2025 02:20:53 +08:00 Committer: Borislav Petkov (AMD) <bp@alien8.de> CommitterDate: Mon, 16 Jun 2025 21:06:12 +02:00 x86,fs/resctrl: Remove inappropriate references to cacheinfo in the resctrl subsystem In the resctrl subsystem's Sub-NUMA Cluster (SNC) mode, the rdt_mon_domain structure representing a NUMA node relies on the cacheinfo interface (rdt_mon_domain::ci) to store L3 cache information (e.g., shared_cpu_map) for monitoring. The L3 cache information of a SNC NUMA node determines which domains are summed for the "top level" L3-scoped events. rdt_mon_domain::ci is initialized using the first online CPU of a NUMA node. When this CPU goes offline, its shared_cpu_map is cleared to contain only the offline CPU itself. Subsequently, attempting to read counters via smp_call_on_cpu(offline_cpu) fails (and error ignored), returning zero values for "top-level events" without any error indication. Replace the cacheinfo references in struct rdt_mon_domain and struct rmid_read with the cacheinfo ID (a unique identifier for the L3 cache). rdt_domain_hdr::cpu_mask contains the online CPUs associated with that domain. When reading "top-level events", select a CPU from rdt_domain_hdr::cpu_mask and utilize its L3 shared_cpu_map to determine valid CPUs for reading RMID counter via the MSR interface. Considering all CPUs associated with the L3 cache improves the chances of picking a housekeeping CPU on which the counter reading work can be queued, avoiding an unnecessary IPI. Fixes: 328ea68874642 ("x86/resctrl: Prepare for new Sub-NUMA Cluster (SNC) monitor files") Signed-off-by: Qinyun Tan <qinyuntan@linux.alibaba.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/20250530182053.37502-2-qinyuntan@linux.alibaba.com --- arch/x86/kernel/cpu/resctrl/core.c | 6 ++++-- fs/resctrl/ctrlmondata.c | 13 +++++++++---- fs/resctrl/internal.h | 4 ++-- fs/resctrl/monitor.c | 6 ++++-- fs/resctrl/rdtgroup.c | 6 +++--- include/linux/resctrl.h | 4 ++-- 6 files changed, 24 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 7109cbf..187d527 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -498,6 +498,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) struct rdt_hw_mon_domain *hw_dom; struct rdt_domain_hdr *hdr; struct rdt_mon_domain *d; + struct cacheinfo *ci; int err; lockdep_assert_held(&domain_list_lock); @@ -525,12 +526,13 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) d = &hw_dom->d_resctrl; d->hdr.id = id; d->hdr.type = RESCTRL_MON_DOMAIN; - d->ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); - if (!d->ci) { + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci) { pr_warn_once("Can't find L3 cache for CPU:%d resource %s\n", cpu, r->name); mon_domain_free(hw_dom); return; } + d->ci_id = ci->id; cpumask_set_cpu(cpu, &d->hdr.cpu_mask); arch_mon_domain_online(r, d); diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index 6ed2dfd..d98e0d2 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -594,9 +594,10 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) struct rmid_read rr = {0}; struct rdt_mon_domain *d; struct rdtgroup *rdtgrp; + int domid, cpu, ret = 0; struct rdt_resource *r; + struct cacheinfo *ci; struct mon_data *md; - int domid, ret = 0; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { @@ -623,10 +624,14 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) * one that matches this cache id. */ list_for_each_entry(d, &r->mon_domains, hdr.list) { - if (d->ci->id == domid) { - rr.ci = d->ci; + if (d->ci_id == domid) { + rr.ci_id = d->ci_id; + cpu = cpumask_any(&d->hdr.cpu_mask); + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci) + continue; mon_event_read(&rr, r, NULL, rdtgrp, - &d->ci->shared_cpu_map, evtid, false); + &ci->shared_cpu_map, evtid, false); goto checkresult; } } diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index 9a8cf6f..0a1eedb 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -98,7 +98,7 @@ struct mon_data { * domains in @r sharing L3 @ci.id * @evtid: Which monitor event to read. * @first: Initialize MBM counter when true. - * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains. + * @ci_id: Cacheinfo id for L3. Only set when @d is NULL. Used when summing domains. * @err: Error encountered when reading counter. * @val: Returned value of event counter. If @rgrp is a parent resource group, * @val includes the sum of event counts from its child resource groups. @@ -112,7 +112,7 @@ struct rmid_read { struct rdt_mon_domain *d; enum resctrl_event_id evtid; bool first; - struct cacheinfo *ci; + unsigned int ci_id; int err; u64 val; void *arch_mon_ctx; diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index bde2801..f563785 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -361,6 +361,7 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) { int cpu = smp_processor_id(); struct rdt_mon_domain *d; + struct cacheinfo *ci; struct mbm_state *m; int err, ret; u64 tval = 0; @@ -388,7 +389,8 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) } /* Summing domains that share a cache, must be on a CPU for that cache. */ - if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map)) + ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); + if (!ci || ci->id != rr->ci_id) return -EINVAL; /* @@ -400,7 +402,7 @@ static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) */ ret = -EINVAL; list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { - if (d->ci->id != rr->ci->id) + if (d->ci_id != rr->ci_id) continue; err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, rr->evtid, &tval, rr->arch_mon_ctx); diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 1beb124..77d0822 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -3036,7 +3036,7 @@ static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, char name[32]; snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci_id : d->hdr.id); if (snc_mode) sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id); @@ -3061,7 +3061,7 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d, return -EPERM; list_for_each_entry(mevt, &r->evt_list, list) { - domid = do_sum ? d->ci->id : d->hdr.id; + domid = do_sum ? d->ci_id : d->hdr.id; priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum); if (WARN_ON_ONCE(!priv)) return -EINVAL; @@ -3089,7 +3089,7 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, lockdep_assert_held(&rdtgroup_mutex); snc_mode = r->mon_scope == RESCTRL_L3_NODE; - sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id); + sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci_id : d->hdr.id); kn = kernfs_find_and_get(parent_kn, name); if (kn) { /* diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 9ba771f..6fb4894 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -159,7 +159,7 @@ struct rdt_ctrl_domain { /** * struct rdt_mon_domain - group of CPUs sharing a resctrl monitor resource * @hdr: common header for different domain types - * @ci: cache info for this domain + * @ci_id: cache info id for this domain * @rmid_busy_llc: bitmap of which limbo RMIDs are above threshold * @mbm_total: saved state for MBM total bandwidth * @mbm_local: saved state for MBM local bandwidth @@ -170,7 +170,7 @@ struct rdt_ctrl_domain { */ struct rdt_mon_domain { struct rdt_domain_hdr hdr; - struct cacheinfo *ci; + unsigned int ci_id; unsigned long *rmid_busy_llc; struct mbm_state *mbm_total; struct mbm_state *mbm_local; ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem. 2025-05-30 18:20 [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem Qinyun Tan 2025-05-30 18:20 ` [PATCH V6 1/1] " Qinyun Tan @ 2025-06-09 17:01 ` Reinette Chatre 1 sibling, 0 replies; 4+ messages in thread From: Reinette Chatre @ 2025-06-09 17:01 UTC (permalink / raw) To: Qinyun Tan, Tony Luck, Borislav Petkov, x86; +Cc: H . Peter Anvin, linux-kernel Dear x86 Maintainers, Could you please consider this resctrl fix for inclusion? Thank you very much. Reinette On 5/30/25 11:20 AM, Qinyun Tan wrote: > V6: > - Modify subject tag "x86/resctrl:" -> "x86,fs/resctrl:" > > V5: > - Modify the commit log format again. I am truly grateful to Reinette > for her thoughtful guidance :). > > V4: > - Add the tested by and reviewed by tags. > - Modify the commit log format. > > V3: > - According to Reinette suggestion, modify the commit log description to > make it easier for readers to understand > > V2: > - Keep sanity checks in the __mon_event_count to ensure execution occurs > exclusively on CPUs sharing the same L3 cache cluster > - When reading the top level event, obtain a CPU within hdr.cpu_mask. > Then use the cacheinfo shared_cpu_map of this CPU instead of using > hdr.cpu_mask directly > - Adjust code formatting and commit log descriptions. > > In the resctrl subsystem's Sub-NUMA Cluster (SNC) mode, the rdt_mon_domain > structure representing a NUMA node relies on the cacheinfo interface > (rdt_mon_domain::ci) to store L3 cache information (e.g., shared_cpu_map) > for monitoring. The L3 cache information of a SNC NUMA node determines > which domains are summed for the "top level" L3-scoped events. > > rdt_mon_domain::ci is initialized using the first online CPU of a NUMA > node. When this CPU goes offline, its shared_cpu_map is cleared to contain > only the offline CPU itself. Subsequently, attempting to read counters > via smp_call_on_cpu(offline_cpu) fails (and error ignored), returning > zero values for "top-level events" without any error indication. > > Replace the cacheinfo references in struct rdt_mon_domain and struct > rmid_read with the cacheinfo ID (a unique identifier for the L3 cache). > > rdt_domain_hdr::cpu_mask contains the online CPUs associated with that > domain. When reading "top-level events", select a CPU from > rdt_domain_hdr::cpu_mask and utilize its L3 shared_cpu_map to determine > valid CPUs for reading RMID counter via the MSR interface. > > Considering all CPUs associated with the L3 cache improves the chances > of picking a housekeeping CPU on which the counter reading work can be > queued, avoiding an unnecessary IPI. > > Qinyun Tan (1): > x86/resctrl: Remove unappropriate references to cacheinfo in the > resctrl subsystem. > > arch/x86/kernel/cpu/resctrl/core.c | 6 ++++-- > fs/resctrl/ctrlmondata.c | 13 +++++++++---- > fs/resctrl/internal.h | 4 ++-- > fs/resctrl/monitor.c | 6 ++++-- > fs/resctrl/rdtgroup.c | 6 +++--- > include/linux/resctrl.h | 4 ++-- > 6 files changed, 24 insertions(+), 15 deletions(-) > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-06-16 19:51 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2025-05-30 18:20 [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate references to cacheinfo in the resctrl subsystem Qinyun Tan 2025-05-30 18:20 ` [PATCH V6 1/1] " Qinyun Tan 2025-06-16 19:51 ` [tip: x86/urgent] x86,fs/resctrl: Remove inappropriate " tip-bot2 for Qinyun Tan 2025-06-09 17:01 ` [PATCH V6 0/1] x86,fs/resctrl: Remove unappropriate " Reinette Chatre
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