From: James Morse <james.morse@arm.com>
To: x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>, Babu Moger <Babu.Moger@amd.com>,
James Morse <james.morse@arm.com>,
shameerali.kolothum.thodi@huawei.com,
D Scott Phillips OS <scott@os.amperecomputing.com>,
lcherian@marvell.com, bobo.shaobowang@huawei.com,
tan.shaopeng@fujitsu.com, Jamie Iles <quic_jiles@quicinc.com>,
Cristian Marussi <cristian.marussi@arm.com>,
Xin Hao <xhao@linux.alibaba.com>,
xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com
Subject: [PATCH v4 15/21] x86/resctrl: Abstract __rmid_read()
Date: Tue, 12 Apr 2022 12:44:13 +0000 [thread overview]
Message-ID: <20220412124419.30689-16-james.morse@arm.com> (raw)
In-Reply-To: <20220412124419.30689-1-james.morse@arm.com>
__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.
Reviewed-by: Jamie Iles <quic_jiles@quicinc.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v3:
* Changed return type of __mon_event_count().
* Clarified comment in mon_event_count()
Changes since v2:
* Capitalisation
* Stray newline restored
* Removed rr->val set to the error value, and replaced it with clearing the
the error to hide Unavailable from monitor group reads. (and added a block
comment).
Changes since v1:
* Return EINVAL from the impossible case in __mon_event_count() instead
of an x86 hardware specific value.
---
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 4 +-
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/monitor.c | 56 +++++++++++++++--------
include/linux/resctrl.h | 1 +
4 files changed, 40 insertions(+), 22 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index ece3a1e0e6f2..d3f7eb2ac14b 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -579,9 +579,9 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
mon_event_read(&rr, r, d, rdtgrp, evtid, false);
- if (rr.val & RMID_VAL_ERROR)
+ if (rr.err == -EIO)
seq_puts(m, "Error\n");
- else if (rr.val & RMID_VAL_UNAVAIL)
+ else if (rr.err == -EINVAL)
seq_puts(m, "Unavailable\n");
else
seq_printf(m, "%llu\n", rr.val * hw_res->mon_scale);
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index b34a1403f033..1d2e7bd6305f 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -94,6 +94,7 @@ struct rmid_read {
struct rdt_domain *d;
enum resctrl_event_id evtid;
bool first;
+ int err;
u64 val;
};
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 71a13c04a846..20c54cbadc0c 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -167,9 +167,9 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
memset(am, 0, sizeof(*am));
}
-static u64 __rmid_read(u32 rmid, enum resctrl_event_id eventid)
+int resctrl_arch_rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val)
{
- u64 val;
+ u64 msr_val;
/*
* As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
@@ -180,14 +180,24 @@ static u64 __rmid_read(u32 rmid, enum resctrl_event_id eventid)
* are error bits.
*/
wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
- rdmsrl(MSR_IA32_QM_CTR, val);
+ rdmsrl(MSR_IA32_QM_CTR, msr_val);
- return val;
+ if (msr_val & RMID_VAL_ERROR)
+ return -EIO;
+ if (msr_val & RMID_VAL_UNAVAIL)
+ return -EINVAL;
+
+ *val = msr_val;
+
+ return 0;
}
static bool rmid_dirty(struct rmid_entry *entry)
{
- u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
+ u64 val = 0;
+
+ if (resctrl_arch_rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID, &val))
+ return true;
return val >= resctrl_cqm_threshold;
}
@@ -259,8 +269,8 @@ static void add_rmid_to_limbo(struct rmid_entry *entry)
{
struct rdt_resource *r;
struct rdt_domain *d;
- int cpu;
- u64 val;
+ int cpu, err;
+ u64 val = 0;
r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
@@ -268,8 +278,10 @@ static void add_rmid_to_limbo(struct rmid_entry *entry)
cpu = get_cpu();
list_for_each_entry(d, &r->domains, list) {
if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
- val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
- if (val <= resctrl_cqm_threshold)
+ err = resctrl_arch_rmid_read(entry->rmid,
+ QOS_L3_OCCUP_EVENT_ID,
+ &val);
+ if (err || val <= resctrl_cqm_threshold)
continue;
}
@@ -315,19 +327,19 @@ static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
return chunks >> shift;
}
-static u64 __mon_event_count(u32 rmid, struct rmid_read *rr)
+static int __mon_event_count(u32 rmid, struct rmid_read *rr)
{
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
struct mbm_state *m;
- u64 chunks, tval;
+ u64 chunks, tval = 0;
if (rr->first)
resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);
- tval = __rmid_read(rmid, rr->evtid);
- if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
- return tval;
- }
+ rr->err = resctrl_arch_rmid_read(rmid, rr->evtid, &tval);
+ if (rr->err)
+ return rr->err;
+
switch (rr->evtid) {
case QOS_L3_OCCUP_EVENT_ID:
rr->val += tval;
@@ -343,7 +355,7 @@ static u64 __mon_event_count(u32 rmid, struct rmid_read *rr)
* Code would never reach here because an invalid
* event id would fail the __rmid_read.
*/
- return RMID_VAL_ERROR;
+ return -EINVAL;
}
if (rr->first) {
@@ -399,7 +411,7 @@ void mon_event_count(void *info)
struct rdtgroup *rdtgrp, *entry;
struct rmid_read *rr = info;
struct list_head *head;
- u64 ret_val;
+ int ret_val;
rdtgrp = rr->rgrp;
@@ -419,9 +431,13 @@ void mon_event_count(void *info)
}
}
- /* Report error if none of rmid_reads are successful */
- if (ret_val)
- rr->val = ret_val;
+ /*
+ * __mon_event_count() calls for newly created monitor groups may
+ * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
+ * Discard error if any of the monitor event reads succeeded.
+ */
+ if (ret_val == 0)
+ rr->err = 0;
}
/*
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 0b48239f5920..70112dbfa128 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
--
2.30.2
next prev parent reply other threads:[~2022-04-12 13:04 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 12:43 [PATCH v4 00/21] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes James Morse
2022-04-12 12:43 ` [PATCH v4 01/21] x86/resctrl: Kill off alloc_enabled James Morse
2022-04-12 12:44 ` [PATCH v4 02/21] x86/resctrl: Merge mon_capable and mon_enabled James Morse
2022-04-12 12:44 ` [PATCH v4 03/21] x86/resctrl: Add domain online callback for resctrl work James Morse
[not found] ` <3acfb11b-eba2-3eb0-94d1-d24a24d03d1f@linux.alibaba.com>
2022-05-03 7:59 ` Xin Hao
2022-04-12 12:44 ` [PATCH v4 04/21] x86/resctrl: Group struct rdt_hw_domain cleanup James Morse
2022-04-12 12:44 ` [PATCH v4 05/21] x86/resctrl: Add domain offline callback for resctrl work James Morse
2022-04-12 12:44 ` [PATCH v4 06/21] x86/resctrl: Remove set_mba_sc()s control array re-initialisation James Morse
2022-04-12 12:44 ` [PATCH v4 07/21] x86/resctrl: Create mba_sc configuration in the rdt_domain James Morse
2022-05-17 16:18 ` Reinette Chatre
2022-06-07 12:07 ` James Morse
2022-05-18 16:06 ` Reinette Chatre
2022-04-12 12:44 ` [PATCH v4 08/21] x86/resctrl: Switch over to the resctrl mbps_val list James Morse
2022-05-17 16:19 ` Reinette Chatre
2022-06-07 12:07 ` James Morse
2022-04-12 12:44 ` [PATCH v4 09/21] x86/resctrl: Remove architecture copy of mbps_val James Morse
2022-04-12 12:44 ` [PATCH v4 10/21] x86/resctrl: Abstract and use supports_mba_mbps() James Morse
2022-04-12 12:44 ` [PATCH v4 11/21] x86/resctrl: Allow update_mba_bw() to update controls directly James Morse
2022-04-12 12:44 ` [PATCH v4 12/21] x86/resctrl: Calculate bandwidth from the previous __mon_event_count() chunks James Morse
2022-04-12 12:44 ` [PATCH v4 13/21] x86/resctrl: Add per-rmid arch private storage for overflow and chunks James Morse
2022-05-18 16:06 ` Reinette Chatre
2022-04-12 12:44 ` [PATCH v4 14/21] x86/resctrl: Allow per-rmid arch private storage to be reset James Morse
2022-04-12 12:44 ` James Morse [this message]
2022-05-17 21:23 ` [PATCH v4 15/21] x86/resctrl: Abstract __rmid_read() Reinette Chatre
2022-06-07 12:07 ` James Morse
2022-06-07 15:51 ` Reinette Chatre
2022-06-07 20:44 ` Fenghua Yu
2022-06-07 21:25 ` Fenghua Yu
2022-04-12 12:44 ` [PATCH v4 16/21] x86/resctrl: Pass the required parameters into resctrl_arch_rmid_read() James Morse
2022-06-07 21:07 ` Fenghua Yu
2022-06-22 15:16 ` James Morse
2022-04-12 12:44 ` [PATCH v4 17/21] x86/resctrl: Move mbm_overflow_count() " James Morse
2022-04-12 12:44 ` [PATCH v4 18/21] x86/resctrl: Move get_corrected_mbm_count() " James Morse
2022-04-12 12:44 ` [PATCH v4 19/21] x86/resctrl: Rename and change the units of resctrl_cqm_threshold James Morse
2022-05-17 21:23 ` Reinette Chatre
2022-06-07 22:08 ` Fenghua Yu
2022-06-22 15:16 ` James Morse
2022-04-12 12:44 ` [PATCH v4 20/21] x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data James Morse
2022-04-12 12:44 ` [PATCH v4 21/21] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes James Morse
2022-04-18 8:09 ` [PATCH v4 00/21] " tan.shaopeng
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