While debugging the error handling patches, I found it useful to trace the allocation and freeing of extent_state structures. As a side note, a huge number of allocations have lifetimes in the < 10 us range.
This patch adds the trace, including caller and object address. Signed-off-by: Jeff Mahoney <je...@suse.com> --- fs/btrfs/extent_io.c | 2 + include/trace/events/btrfs.h | 44 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -141,6 +141,7 @@ static struct extent_state *alloc_extent #endif atomic_set(&state->refs, 1); init_waitqueue_head(&state->wq); + trace_alloc_extent_state(state, mask, _RET_IP_); return state; } @@ -158,6 +159,7 @@ void free_extent_state(struct extent_sta list_del(&state->leak_list); spin_unlock_irqrestore(&leak_lock, flags); #endif + trace_free_extent_state(state, _RET_IP_); kmem_cache_free(extent_state_cache, state); } } --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -6,6 +6,7 @@ #include <linux/writeback.h> #include <linux/tracepoint.h> +#include <trace/events/gfpflags.h> struct btrfs_root; struct btrfs_fs_info; @@ -661,6 +662,49 @@ DEFINE_EVENT(btrfs__reserved_extent, bt TP_ARGS(root, start, len) ); +struct extent_state; +TRACE_EVENT(alloc_extent_state, + + TP_PROTO(struct extent_state *state, gfp_t mask, unsigned long IP), + + TP_ARGS(state, mask, IP), + + TP_STRUCT__entry( + __field(struct extent_state *, state) + __field(gfp_t, mask) + __field(unsigned long, ip) + ), + + TP_fast_assign( + __entry->state = state, + __entry->mask = mask, + __entry->ip = IP + ), + + TP_printk("state=%p; mask = %s; caller = %pF", __entry->state, + show_gfp_flags(__entry->mask), (void *)__entry->ip) +); + +TRACE_EVENT(free_extent_state, + + TP_PROTO(struct extent_state *state, unsigned long IP), + + TP_ARGS(state, IP), + + TP_STRUCT__entry( + __field(struct extent_state *, state) + __field(unsigned long, ip) + ), + + TP_fast_assign( + __entry->state = state, + __entry->ip = IP + ), + + TP_printk(" state=%p; caller = %pF", __entry->state, + (void *)__entry->ip) +); + #endif /* _TRACE_BTRFS_H */ /* This part must be outside protection */ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html