[PATCH v2 4/4] powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform
Nicholas Piggin
npiggin at gmail.com
Fri Sep 2 18:53:16 AEST 2022
dtl is the PAPR Dispatch Trace Log, which is entirely a pseries feature.
The pseries platform alrady has a file dealing with the dtl, so move
scanning for stolen time accounting there from kernel/time.c.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/cputime.h | 2 +-
arch/powerpc/include/asm/dtl.h | 8 ---
arch/powerpc/include/asm/time.h | 5 +-
arch/powerpc/kernel/time.c | 92 ++--------------------------
arch/powerpc/platforms/pseries/dtl.c | 81 ++++++++++++++++++++++++
5 files changed, 90 insertions(+), 98 deletions(-)
diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
index 6d2b27997492..431ae2343022 100644
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -95,7 +95,7 @@ static notrace inline void account_stolen_time(void)
struct lppaca *lp = local_paca->lppaca_ptr;
if (unlikely(local_paca->dtl_ridx != be64_to_cpu(lp->dtl_idx)))
- accumulate_stolen_time();
+ pseries_accumulate_stolen_time();
}
#endif
}
diff --git a/arch/powerpc/include/asm/dtl.h b/arch/powerpc/include/asm/dtl.h
index 1625888f27ef..4bcb9f9ac764 100644
--- a/arch/powerpc/include/asm/dtl.h
+++ b/arch/powerpc/include/asm/dtl.h
@@ -37,14 +37,6 @@ struct dtl_entry {
extern struct kmem_cache *dtl_cache;
extern rwlock_t dtl_access_lock;
-/*
- * When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE = y, the cpu accounting code controls
- * reading from the dispatch trace log. If other code wants to consume
- * DTL entries, it can set this pointer to a function that will get
- * called once for each DTL entry that gets processed.
- */
-extern void (*dtl_consumer)(struct dtl_entry *entry, u64 index);
-
extern void register_dtl_buffer(int cpu);
extern void alloc_dtl_buffers(unsigned long *time_limit);
extern long hcall_vphn(unsigned long cpu, u64 flags, __be32 *associativity);
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 1e5643a9b1f2..9f50766c4623 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -116,8 +116,9 @@ unsigned long long tb_to_ns(unsigned long long tb_ticks);
void timer_broadcast_interrupt(void);
-/* SPLPAR */
-void accumulate_stolen_time(void);
+/* SPLPAR and VIRT_CPU_ACCOUNTING_NATIVE */
+void pseries_accumulate_stolen_time(void);
+u64 pseries_calculate_stolen_time(u64 stop_tb);
#endif /* __KERNEL__ */
#endif /* __POWERPC_TIME_H */
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 587adcc12860..ae3e33b4ef95 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -178,92 +178,6 @@ static inline unsigned long read_spurr(unsigned long tb)
return tb;
}
-#ifdef CONFIG_PPC_SPLPAR
-
-#include <asm/dtl.h>
-
-void (*dtl_consumer)(struct dtl_entry *, u64);
-
-/*
- * Scan the dispatch trace log and count up the stolen time.
- * Should be called with interrupts disabled.
- */
-static u64 scan_dispatch_log(u64 stop_tb)
-{
- u64 i = local_paca->dtl_ridx;
- struct dtl_entry *dtl = local_paca->dtl_curr;
- struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
- struct lppaca *vpa = local_paca->lppaca_ptr;
- u64 tb_delta;
- u64 stolen = 0;
- u64 dtb;
-
- if (!dtl)
- return 0;
-
- if (i == be64_to_cpu(vpa->dtl_idx))
- return 0;
- while (i < be64_to_cpu(vpa->dtl_idx)) {
- dtb = be64_to_cpu(dtl->timebase);
- tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
- be32_to_cpu(dtl->ready_to_enqueue_time);
- barrier();
- if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
- /* buffer has overflowed */
- i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
- dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
- continue;
- }
- if (dtb > stop_tb)
- break;
- if (dtl_consumer)
- dtl_consumer(dtl, i);
- stolen += tb_delta;
- ++i;
- ++dtl;
- if (dtl == dtl_end)
- dtl = local_paca->dispatch_log;
- }
- local_paca->dtl_ridx = i;
- local_paca->dtl_curr = dtl;
- return stolen;
-}
-
-/*
- * Accumulate stolen time by scanning the dispatch trace log.
- * Called on entry from user mode.
- */
-void notrace accumulate_stolen_time(void)
-{
- u64 sst, ust;
- struct cpu_accounting_data *acct = &local_paca->accounting;
-
- sst = scan_dispatch_log(acct->starttime_user);
- ust = scan_dispatch_log(acct->starttime);
- acct->stime -= sst;
- acct->utime -= ust;
- acct->steal_time += ust + sst;
-}
-
-static inline u64 calculate_stolen_time(u64 stop_tb)
-{
- if (!firmware_has_feature(FW_FEATURE_SPLPAR))
- return 0;
-
- if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
- return scan_dispatch_log(stop_tb);
-
- return 0;
-}
-
-#else /* CONFIG_PPC_SPLPAR */
-static inline u64 calculate_stolen_time(u64 stop_tb)
-{
- return 0;
-}
-
-#endif /* CONFIG_PPC_SPLPAR */
-
/*
* Account time for a transition between system, hard irq
* or soft irq state.
@@ -322,7 +236,11 @@ static unsigned long vtime_delta(struct cpu_accounting_data *acct,
*stime_scaled = vtime_delta_scaled(acct, now, stime);
- *steal_time = calculate_stolen_time(now);
+ if (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
+ firmware_has_feature(FW_FEATURE_SPLPAR))
+ *steal_time = pseries_calculate_stolen_time(now);
+ else
+ *steal_time = 0;
return stime;
}
diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index 352af5b14a0f..1b1977bc78e7 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -37,6 +37,15 @@ static u8 dtl_event_mask = DTL_LOG_ALL;
static int dtl_buf_entries = N_DISPATCH_LOG;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+
+/*
+ * When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE = y, the cpu accounting code controls
+ * reading from the dispatch trace log. If other code wants to consume
+ * DTL entries, it can set this pointer to a function that will get
+ * called once for each DTL entry that gets processed.
+ */
+static void (*dtl_consumer)(struct dtl_entry *entry, u64 index);
+
struct dtl_ring {
u64 write_index;
struct dtl_entry *write_ptr;
@@ -48,6 +57,78 @@ static DEFINE_PER_CPU(struct dtl_ring, dtl_rings);
static atomic_t dtl_count;
+/*
+ * Scan the dispatch trace log and count up the stolen time.
+ * Should be called with interrupts disabled.
+ */
+static notrace u64 scan_dispatch_log(u64 stop_tb)
+{
+ u64 i = local_paca->dtl_ridx;
+ struct dtl_entry *dtl = local_paca->dtl_curr;
+ struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
+ struct lppaca *vpa = local_paca->lppaca_ptr;
+ u64 tb_delta;
+ u64 stolen = 0;
+ u64 dtb;
+
+ if (!dtl)
+ return 0;
+
+ if (i == be64_to_cpu(vpa->dtl_idx))
+ return 0;
+ while (i < be64_to_cpu(vpa->dtl_idx)) {
+ dtb = be64_to_cpu(dtl->timebase);
+ tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
+ be32_to_cpu(dtl->ready_to_enqueue_time);
+ barrier();
+ if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
+ /* buffer has overflowed */
+ i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
+ dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
+ continue;
+ }
+ if (dtb > stop_tb)
+ break;
+ if (dtl_consumer)
+ dtl_consumer(dtl, i);
+ stolen += tb_delta;
+ ++i;
+ ++dtl;
+ if (dtl == dtl_end)
+ dtl = local_paca->dispatch_log;
+ }
+ local_paca->dtl_ridx = i;
+ local_paca->dtl_curr = dtl;
+ return stolen;
+}
+
+/*
+ * Accumulate stolen time by scanning the dispatch trace log.
+ * Called on entry from user mode.
+ */
+void notrace pseries_accumulate_stolen_time(void)
+{
+ u64 sst, ust;
+ struct cpu_accounting_data *acct = &local_paca->accounting;
+
+ sst = scan_dispatch_log(acct->starttime_user);
+ ust = scan_dispatch_log(acct->starttime);
+ acct->stime -= sst;
+ acct->utime -= ust;
+ acct->steal_time += ust + sst;
+}
+
+u64 pseries_calculate_stolen_time(u64 stop_tb)
+{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return 0;
+
+ if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
+ return scan_dispatch_log(stop_tb);
+
+ return 0;
+}
+
/*
* The cpu accounting code controls the DTL ring buffer, and we get
* given entries as they are processed.
--
2.37.2
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