bcachefs: Fix slow tracepoints

Some of our tracepoints were calling snprintf("pS") - which does symbol
table lookups - in TP_fast_assign(), which turns out to be a really bad
idea.

This was done because perf trace wasn't correctly printing tracepoints
that use %pS anymore - but it turns out trace-cmd does handle it
correctly.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h
index 5e78c396e24cc3f47192d132fcd7532f0d64dab9..64b7d9364fd91bfb98608ec1366060fbc16faab0 100644 (file)
--- a/fs/bcachefs/trace.h
+++ b/fs/bcachefs/trace.h
@@ -358,7 +358,7 @@ TRACE_EVENT(btree_node_relock_fail,
 
        TP_STRUCT__entry(
                __array(char,                   trans_fn, 24    )
-               __array(char,                   caller, 32      )
+               __field(unsigned long,          caller_ip       )
                __field(u8,                     btree_id        )
                __field(u64,                    pos_inode       )
                __field(u64,                    pos_offset      )
@@ -370,7 +370,7 @@ TRACE_EVENT(btree_node_relock_fail,
 
        TP_fast_assign(
                strncpy(__entry->trans_fn, trans_fn, sizeof(__entry->trans_fn));
-               snprintf(__entry->caller, sizeof(__entry->caller), "%pS", (void *) caller_ip);
+               __entry->caller_ip              = caller_ip;
                __entry->btree_id               = btree_id;
                __entry->pos_inode              = pos->inode;
                __entry->pos_offset             = pos->offset;
@@ -380,9 +380,9 @@ TRACE_EVENT(btree_node_relock_fail,
                __entry->node_lock_seq          = node_lock_seq;
        ),
 
-       TP_printk("%s %s btree %u pos %llu:%llu:%u, node %lu iter seq %u lock seq %u",
+       TP_printk("%s %pS btree %u pos %llu:%llu:%u, node %lu iter seq %u lock seq %u",
                  __entry->trans_fn,
-                 __entry->caller,
+                 (void *) __entry->caller_ip,
                  __entry->btree_id,
                  __entry->pos_inode,
                  __entry->pos_offset,
@@ -673,7 +673,7 @@ DECLARE_EVENT_CLASS(transaction_restart_iter,
 
        TP_STRUCT__entry(
                __array(char,                   trans_fn, 24    )
-               __array(char,                   caller, 32      )
+               __field(unsigned long,          caller_ip       )
                __field(u8,                     btree_id        )
                __field(u64,                    pos_inode       )
                __field(u64,                    pos_offset      )
@@ -682,16 +682,16 @@ DECLARE_EVENT_CLASS(transaction_restart_iter,
 
        TP_fast_assign(
                strncpy(__entry->trans_fn, trans_fn, sizeof(__entry->trans_fn));
-               snprintf(__entry->caller, sizeof(__entry->caller), "%pS", (void *) caller_ip);
+               __entry->caller_ip              = caller_ip;
                __entry->btree_id               = btree_id;
                __entry->pos_inode              = pos->inode;
                __entry->pos_offset             = pos->offset;
                __entry->pos_snapshot           = pos->snapshot;
        ),
 
-       TP_printk("%s %s btree %u pos %llu:%llu:%u",
+       TP_printk("%s %pS btree %u pos %llu:%llu:%u",
                  __entry->trans_fn,
-                 __entry->caller,
+                 (void *) __entry->caller_ip,
                  __entry->btree_id,
                  __entry->pos_inode,
                  __entry->pos_offset,