[PATCH v8 3/7] x86/resctrl: Refactor mbm_update()

From: Tony Luck
Date: Tue Oct 29 2024 - 13:33:53 EST


Computing memory bandwidth for all enabled events resulted in
identical code blocks for total and local bandwidth in mbm_update().

Refactor with a helper function to eliminate code duplication.

No functional change.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/resctrl/monitor.c | 69 ++++++++++-----------------
1 file changed, 24 insertions(+), 45 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 3ef339e405c2..1b6cb3bbc008 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -829,62 +829,41 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
}

-static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
- u32 closid, u32 rmid)
+static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid, enum resctrl_event_id evtid)
{
struct rmid_read rr = {0};

rr.r = r;
rr.d = d;
+ rr.evtid = evtid;
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx)) {
+ pr_warn_ratelimited("Failed to allocate monitor context: %ld",
+ PTR_ERR(rr.arch_mon_ctx));
+ return;
+ }
+
+ __mon_event_count(closid, rmid, &rr);
+
+ if (is_mba_sc(NULL))
+ mbm_bw_count(closid, rmid, &rr);
+
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
+}

+static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid)
+{
/*
* This is protected from concurrent reads from user
* as both the user and we hold the global mutex.
*/
- if (is_mbm_total_enabled()) {
- rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
- rr.val = 0;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
- }
-
- __mon_event_count(closid, rmid, &rr);
-
- /*
- * Call the MBA software controller only for the
- * control groups and when user has enabled
- * the software controller explicitly.
- */
- if (is_mba_sc(NULL))
- mbm_bw_count(closid, rmid, &rr);
-
- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
- }
- if (is_mbm_local_enabled()) {
- rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
- rr.val = 0;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
- }
-
- __mon_event_count(closid, rmid, &rr);
-
- /*
- * Call the MBA software controller only for the
- * control groups and when user has enabled
- * the software controller explicitly.
- */
- if (is_mba_sc(NULL))
- mbm_bw_count(closid, rmid, &rr);
+ if (is_mbm_total_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);

- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
- }
+ if (is_mbm_local_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
}

/*
--
2.47.0