[PATCH 4/4] percpu: add tracepoint support for percpu memory
From: Dennis Zhou
Date: Mon Jun 19 2017 - 19:29:05 EST
Add support for tracepoints to the following events: chunk allocation,
chunk free, area allocation, area free, and area allocation failure.
This should let us replay percpu memory requests and evaluate
corresponding decisions.
Signed-off-by: Dennis Zhou <dennisz@xxxxxx>
---
include/trace/events/percpu.h | 125 ++++++++++++++++++++++++++++++++++++++++++
mm/percpu-km.c | 2 +
mm/percpu-vm.c | 2 +
mm/percpu.c | 12 ++++
4 files changed, 141 insertions(+)
create mode 100644 include/trace/events/percpu.h
diff --git a/include/trace/events/percpu.h b/include/trace/events/percpu.h
new file mode 100644
index 0000000..ad34b1b
--- /dev/null
+++ b/include/trace/events/percpu.h
@@ -0,0 +1,125 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM percpu
+
+#if !defined(_TRACE_PERCPU_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PERCPU_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(percpu_alloc_percpu,
+
+ TP_PROTO(bool reserved, bool is_atomic, size_t size,
+ size_t align, void *base_addr, int off, void __percpu *ptr),
+
+ TP_ARGS(reserved, is_atomic, size, align, base_addr, off, ptr),
+
+ TP_STRUCT__entry(
+ __field( bool, reserved )
+ __field( bool, is_atomic )
+ __field( size_t, size )
+ __field( size_t, align )
+ __field( void *, base_addr )
+ __field( int, off )
+ __field( void __percpu *, ptr )
+ ),
+
+ TP_fast_assign(
+ __entry->reserved = reserved;
+ __entry->is_atomic = is_atomic;
+ __entry->size = size;
+ __entry->align = align;
+ __entry->base_addr = base_addr;
+ __entry->off = off;
+ __entry->ptr = ptr;
+ ),
+
+ TP_printk("reserved=%d is_atomic=%d size=%zu align=%zu base_addr=%p off=%d ptr=%p",
+ __entry->reserved, __entry->is_atomic,
+ __entry->size, __entry->align,
+ __entry->base_addr, __entry->off, __entry->ptr)
+);
+
+TRACE_EVENT(percpu_free_percpu,
+
+ TP_PROTO(void *base_addr, int off, void __percpu *ptr),
+
+ TP_ARGS(base_addr, off, ptr),
+
+ TP_STRUCT__entry(
+ __field( void *, base_addr )
+ __field( int, off )
+ __field( void __percpu *, ptr )
+ ),
+
+ TP_fast_assign(
+ __entry->base_addr = base_addr;
+ __entry->off = off;
+ __entry->ptr = ptr;
+ ),
+
+ TP_printk("base_addr=%p off=%d ptr=%p",
+ __entry->base_addr, __entry->off, __entry->ptr)
+);
+
+TRACE_EVENT(percpu_alloc_percpu_fail,
+
+ TP_PROTO(bool reserved, bool is_atomic, size_t size, size_t align),
+
+ TP_ARGS(reserved, is_atomic, size, align),
+
+ TP_STRUCT__entry(
+ __field( bool, reserved )
+ __field( bool, is_atomic )
+ __field( size_t, size )
+ __field( size_t, align )
+ ),
+
+ TP_fast_assign(
+ __entry->reserved = reserved;
+ __entry->is_atomic = is_atomic;
+ __entry->size = size;
+ __entry->align = align;
+ ),
+
+ TP_printk("reserved=%d is_atomic=%d size=%zu align=%zu",
+ __entry->reserved, __entry->is_atomic,
+ __entry->size, __entry->align)
+);
+
+TRACE_EVENT(percpu_create_chunk,
+
+ TP_PROTO(void *base_addr),
+
+ TP_ARGS(base_addr),
+
+ TP_STRUCT__entry(
+ __field( void *, base_addr )
+ ),
+
+ TP_fast_assign(
+ __entry->base_addr = base_addr;
+ ),
+
+ TP_printk("base_addr=%p", __entry->base_addr)
+);
+
+TRACE_EVENT(percpu_destroy_chunk,
+
+ TP_PROTO(void *base_addr),
+
+ TP_ARGS(base_addr),
+
+ TP_STRUCT__entry(
+ __field( void *, base_addr )
+ ),
+
+ TP_fast_assign(
+ __entry->base_addr = base_addr;
+ ),
+
+ TP_printk("base_addr=%p", __entry->base_addr)
+);
+
+#endif /* _TRACE_PERCPU_H */
+
+#include <trace/define_trace.h>
diff --git a/mm/percpu-km.c b/mm/percpu-km.c
index 3bbfa0c..2b79e43 100644
--- a/mm/percpu-km.c
+++ b/mm/percpu-km.c
@@ -73,6 +73,7 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
spin_unlock_irq(&pcpu_lock);
pcpu_stats_chunk_alloc();
+ trace_percpu_create_chunk(chunk->base_addr);
return chunk;
}
@@ -82,6 +83,7 @@ static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
pcpu_stats_chunk_dealloc();
+ trace_percpu_destroy_chunk(chunk->base_addr);
if (chunk && chunk->data)
__free_pages(chunk->data, order_base_2(nr_pages));
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
index 5915a22..7ad9d94 100644
--- a/mm/percpu-vm.c
+++ b/mm/percpu-vm.c
@@ -345,6 +345,7 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
pcpu_stats_chunk_alloc();
+ trace_percpu_create_chunk(chunk->base_addr);
return chunk;
}
@@ -352,6 +353,7 @@ static struct pcpu_chunk *pcpu_create_chunk(void)
static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
{
pcpu_stats_chunk_dealloc();
+ trace_percpu_destroy_chunk(chunk->base_addr);
if (chunk && chunk->data)
pcpu_free_vm_areas(chunk->data, pcpu_nr_groups);
diff --git a/mm/percpu.c b/mm/percpu.c
index 25b4ba5..7a1707a 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -76,6 +76,9 @@
#include <asm/tlbflush.h>
#include <asm/io.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/percpu.h>
+
#include "percpu-internal.h"
#define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */
@@ -1015,11 +1018,17 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
kmemleak_alloc_percpu(ptr, size, gfp);
+
+ trace_percpu_alloc_percpu(reserved, is_atomic, size, align,
+ chunk->base_addr, off, ptr);
+
return ptr;
fail_unlock:
spin_unlock_irqrestore(&pcpu_lock, flags);
fail:
+ trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align);
+
if (!is_atomic && warn_limit) {
pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n",
size, align, is_atomic, err);
@@ -1269,6 +1278,8 @@ void free_percpu(void __percpu *ptr)
}
}
+ trace_percpu_free_percpu(chunk->base_addr, off, ptr);
+
spin_unlock_irqrestore(&pcpu_lock, flags);
}
EXPORT_SYMBOL_GPL(free_percpu);
@@ -1719,6 +1730,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_chunk_relocate(pcpu_first_chunk, -1);
pcpu_stats_chunk_alloc();
+ trace_percpu_create_chunk(base_addr);
/* we're done */
pcpu_base_addr = base_addr;
--
2.9.3