From df95e795a722892a9e0603ce4b9b62fab9f02967 Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Mon, 19 Jun 2017 19:28:32 -0400 Subject: [PATCH] percpu: add tracepoint support for percpu memory 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 Signed-off-by: Tejun Heo --- 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 000000000000..ad34b1bae047 --- /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 + +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 diff --git a/mm/percpu-km.c b/mm/percpu-km.c index 3bbfa0c9d069..2b79e43c626f 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 5915a224da52..7ad9d94bf547 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 44a1cadf74a7..a5bc3634d2a9 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -76,6 +76,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + #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;