benchmark: rework kernel entry/exit tracing

Signed-off-by: Axel Heider <[email protected]>

include/benchmark/benchmark.h

@@ -8,28 +8,26 @@
 
 #include <config.h>
 #include <util.h>
-
-#ifdef CONFIG_ENABLE_BENCHMARKS
-
 #include <types.h>
-#include <arch/benchmark.h>
 #include <machine/io.h>
 #include <sel4/arch/constants.h>
 #include <arch/machine/hardware.h>
 #include <mode/hardware.h>
+#include <arch/benchmark.h>
 
 #ifdef CONFIG_KERNEL_LOG_BUFFER
 extern seL4_Word ksLogIndex = 0;
 extern paddr_t ksUserLogBuffer;
 #endif /* CONFIG_KERNEL_LOG_BUFFER */
 
-#if defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES) || defined(CONFIG_BENCHMARK_TRACK_UTILISATION)
-/* Having one global kernel entry timestamp does not work in SMP configurations,
- * as the kernel could be entered in parallel on different cores. For now, it is
- * assumed that benchmarking is used on single core configurations only.
- */
+#if defined(CONFIG_DEBUG_BUILD) || defined(ENABLE_TRACE_KERNEL_ENTRY_EXIT)
+#include <sel4/benchmark_track_types.h>
+extern kernel_entry_t ksKernelEntry;
+#endif /* CONFIG_DEBUG_BUILD || ENABLE_TRACE_KERNEL_ENTRY_EXIT */
+
+#ifdef CONFIG_BENCHMARK_TRACK_UTILISATION
 extern timestamp_t ksEnter;
-#endif /* CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES CONFIG_BENCHMARK_TRACK_UTILISATION */
+#endif /* CONFIG_BENCHMARK_TRACK_UTILISATION */
 
 #ifdef ENABLE_KERNEL_TRACEPOINTS
 #include <sel4/benchmark_tracepoints_types.h>
@@ -42,6 +40,12 @@ void trace_point_stop(word_t id);
 #define TRACE_POINT_STOP(...)   do {} while(0)
 #endif /* [not] ENABLE_KERNEL_TRACEPOINTS */
 
+#ifdef ENABLE_TRACE_KERNEL_ENTRY_EXIT
+void trace_kernel_entry(void);
+void trace_kernel_exit(void);
+#endif /* ENABLE_TRACE_KERNEL_ENTRY_EXIT */
+
+#ifdef CONFIG_ENABLE_BENCHMARKS
 exception_t handle_SysBenchmarkFlushCaches(void);
 exception_t handle_SysBenchmarkResetLog(void);
 exception_t handle_SysBenchmarkFinalizeLog(void);
@@ -56,5 +60,4 @@ exception_t handle_SysBenchmarkDumpAllThreadsUtilisation(void);
 exception_t handle_SysBenchmarkResetAllThreadsUtilisation(void);
 #endif /* CONFIG_DEBUG_BUILD */
 #endif /* CONFIG_BENCHMARK_TRACK_UTILISATION */
-
 #endif /* CONFIG_ENABLE_BENCHMARKS */

include/benchmark/benchmark_track.h

@@ -7,39 +7,17 @@
 #pragma once
 
 #include <config.h>
+#include <benchmark/benchmark.h>
 
-#if defined(CONFIG_DEBUG_BUILD) || defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES)
+#ifdef ENABLE_TRACE_KERNEL_ENTRY
 
-#include <benchmark/benchmark.h>
 #include <sel4/benchmark_track_types.h>
 #include <sel4/arch/constants.h>
 #include <machine/io.h>
 #include <kernel/cspace.h>
 #include <model/statedata.h>
 #include <mode/machine.h>
 
-#define TRACK_KERNEL_ENTRIES 1
-extern kernel_entry_t ksKernelEntry;
-
-#ifdef CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES
-
-/**
- * @brief Fill in logging info for kernel entries
- *
- */
-void benchmark_track_exit(void);
-
-/**
- * @brief Start logging kernel entries
- *
- */
-static inline void benchmark_track_start(void)
-{
-    ksEnter = timestamp();
-}
-
-#endif /* CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES */
-
 static inline void benchmark_debug_syscall_start(word_t cptr, word_t msgInfo, word_t syscall)
 {
     seL4_MessageInfo_t info = messageInfoFromWord_raw(msgInfo);
@@ -50,4 +28,4 @@ static inline void benchmark_debug_syscall_start(word_t cptr, word_t msgInfo, wo
     ksKernelEntry.invocation_tag = seL4_MessageInfo_get_label(info);
 }
 
-#endif /* CONFIG_DEBUG_BUILD || CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES */
+#endif /* ENABLE_TRACE_KERNEL_ENTRY_EXIT */

include/config.h

@@ -19,6 +19,17 @@
 #endif
 #endif
 
+#if defined(CONFIG_DEBUG_BUILD) || \
+    defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES)
+#define ENABLE_TRACE_KERNEL_ENTRY
+#define TRACK_KERNEL_ENTRIES 1
+#endif
+
+#if defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES) || \
+    defined(CONFIG_BENCHMARK_TRACK_UTILISATION)
+#define ENABLE_TRACE_KERNEL_ENTRY_EXIT
+#endif
+
 #if defined(CONFIG_BENCHMARK_TRACEPOINTS) && (CONFIG_MAX_NUM_TRACE_POINTS > 0)
 #define ENABLE_KERNEL_TRACEPOINTS
 #endif

include/kernel/traps.h

@@ -7,18 +7,17 @@
 #pragma once
 
 #include <config.h>
-#include <util.h>
 #include <arch/kernel/traps.h>
-#include <smp/lock.h>
+#include <benchmark/benchmark.h>
 
 /* This C function should be the first thing called from C after entry from
  * assembly. It provides a single place to do any entry work that is not
  * done in assembly for various reasons */
 static inline void c_entry_hook(void)
 {
     arch_c_entry_hook();
-#if defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES) || defined(CONFIG_BENCHMARK_TRACK_UTILISATION)
-    ksEnter = timestamp();
+#ifdef ENABLE_TRACE_KERNEL_ENTRY_EXIT
+    trace_kernel_entry();
 #endif
 }
 
@@ -28,19 +27,8 @@ static inline void c_entry_hook(void)
  * in C before leaving the kernel */
 static inline void c_exit_hook(void)
 {
-#ifdef CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES
-    benchmark_track_exit();
-#endif /* CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES */
-#ifdef CONFIG_BENCHMARK_TRACK_UTILISATION
-    if (likely(NODE_STATE(benchmark_log_utilisation_enabled))) {
-        timestamp_t exit = timestamp();
-        NODE_STATE(ksCurThread)->benchmark.number_kernel_entries++;
-        NODE_STATE(ksCurThread)->benchmark.kernel_utilisation += exit - ksEnter;
-        NODE_STATE(benchmark_kernel_number_entries)++;
-        NODE_STATE(benchmark_kernel_time) += exit - ksEnter;
-    }
-#endif /* CONFIG_BENCHMARK_TRACK_UTILISATION */
-
+#ifdef ENABLE_TRACE_KERNEL_ENTRY_EXIT
+    trace_kernel_exit();
+#endif
     arch_c_exit_hook();
 }
-

src/arch/x86/machine/breakpoint.c

@@ -592,10 +592,6 @@ exception_t handleUserLevelDebugException(int int_vector)
     ksKernelEntry.word = int_vector;
 #endif /* DEBUG */
 
-#ifdef CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES
-    benchmark_track_start();
-#endif
-
     ct = NODE_STATE(ksCurThread);
 
     /* Software break request (INT3) is detected by the vector number */

src/benchmark/benchmark.c

@@ -19,14 +19,61 @@ seL4_Word ksLogIndex = 0;
 paddr_t ksUserLogBuffer;
 #endif /* CONFIG_KERNEL_LOG_BUFFER */
 
-#if defined(CONFIG_DEBUG_BUILD) || defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES)
+#if defined(CONFIG_DEBUG_BUILD) || defined(ENABLE_TRACE_KERNEL_ENTRY_EXIT)
 #include <sel4/benchmark_track_types.h>
 kernel_entry_t ksKernelEntry;
-#endif /* CONFIG_DEBUG_BUILD || CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES */
+#endif /* CONFIG_DEBUG_BUILD || ENABLE_TRACE_KERNEL_ENTRY_EXIT */
+
+#ifdef ENABLE_TRACE_KERNEL_ENTRY_EXIT
 
-#if defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES) || defined(CONFIG_BENCHMARK_TRACK_UTILISATION)
 timestamp_t ksEnter;
-#endif /* CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES CONFIG_BENCHMARK_TRACK_UTILISATION */
+
+void trace_kernel_entry(void)
+{
+    ksEnter = timestamp();
+
+    ksKernelEntry = (kernel_entry_t) {
+        .path = 0,
+        /* 29 bits are remaining, usage specific to path */
+        .core = CURRENT_CPU_INDEX(), /* 3 bits */
+        .word = 0, /* 26 bits */
+    };
+}
+
+void trace_kernel_exit(void)
+{
+#if defined(CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES) || \
+    defined(CONFIG_BENCHMARK_TRACK_UTILISATION)
+
+    timestamp_t now = timestamp();
+    timestamp_t duration = now - ksEnter;
+
+#endif
+
+#ifdef CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES
+    if (likely(ksUserLogBuffer != 0)) {
+        /* If Log buffer is filled, do nothing */
+        if (likely(ksLogIndex < (seL4_LogBufferSize / sizeof(benchmark_track_kernel_entry_t)))) {
+            benchmark_track_kernel_entry_t *ksLog = (benchmark_track_kernel_entry_t *)KS_LOG_PPTR;
+            ksLog[ksLogIndex].entry = ksKernelEntry;
+            ksLog[ksLogIndex].start_time = ksEnter;
+            ksLog[ksLogIndex].duration = duration;
+            ksLogIndex++;
+        }
+    }
+#endif /* CONFIG_BENCHMARK_TRACK_KERNEL_ENTRIES */
+
+#ifdef CONFIG_BENCHMARK_TRACK_UTILISATION
+    if (likely(NODE_STATE(benchmark_log_utilisation_enabled))) {
+        NODE_STATE(ksCurThread)->benchmark.number_kernel_entries++;
+        NODE_STATE(ksCurThread)->benchmark.kernel_utilisation += duration;
+        NODE_STATE(benchmark_kernel_number_entries)++;
+        NODE_STATE(benchmark_kernel_time) += duration;
+    }
+#endif /* CONFIG_BENCHMARK_TRACK_UTILISATION */
+}
+
+#endif /* ENABLE_TRACE_KERNEL_ENTRY_EXIT */
 
 
 #ifdef ENABLE_KERNEL_TRACEPOINTS

src/config.cmake

@@ -35,7 +35,6 @@ add_sources(
         src/machine/registerset.c
         src/machine/fpu.c
         src/benchmark/benchmark.c
-        src/benchmark/benchmark_track.c
         src/benchmark/benchmark_utilisation.c
         src/smp/lock.c
         src/smp/ipi.c