diff mbox series

[v2,4/4] powerpc/pseries: Move dtl scanning and steal time accounting to pseries platform

Message ID 20220902085316.2071519-5-npiggin@gmail.com (mailing list archive)
State Accepted
Headers show
Series powerpc: stolen time accounting for VIRT_CPU_ACCOUNTING_GEN | expand

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Commit Message

Nicholas Piggin Sept. 2, 2022, 8:53 a.m. UTC
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@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(-)

Comments

Guenter Roeck Oct. 10, 2022, 8:49 p.m. UTC | #1
On Fri, Sep 02, 2022 at 06:53:16PM +1000, Nicholas Piggin wrote:
> 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@gmail.com>

This patch ties DTL to PPC_SPLPAR without updating configuration
dependencies. As result, the following build error may now be seen
if CONFIG_PPC_SPLPAR=y and CONFIG_DTL=n.

arch/powerpc/kernel/irq.o: in function `.do_IRQ':
irq.c:(.text+0x2798): undefined reference to `.pseries_accumulate_stolen_time'

I updated my own configurations to avoid the problem, but you might see
randconfig failures with this error in the future.

Guenter
diff mbox series

Patch

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.