mm: report a more useful address for reclaim acquisition

A recent lockdep report included these lines:

[   96.177910] 3 locks held by containerd/770:
[   96.177934]  #0: ffff88810815ea28 (&mm->mmap_lock#2){++++}-{3:3},
at: do_user_addr_fault+0x115/0x770
[   96.177999]  #1: ffffffff82915020 (rcu_read_lock){....}-{1:2}, at:
get_swap_device+0x33/0x140
[   96.178057]  #2: ffffffff82955ba0 (fs_reclaim){+.+.}-{0:0}, at:
__fs_reclaim_acquire+0x5/0x30

While it was not useful to that bug report to know where the reclaim lock
had been acquired, it might be useful under other circumstances.  Allow
the caller of __fs_reclaim_acquire to specify the instruction pointer to
use.

Link: https://lkml.kernel.org/r/20210719185709.1755149-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eeae2f6bc532..17c4b3fdd7dd 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3812,7 +3812,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx)
 
 	set_task_reclaim_state(current, &sc.reclaim_state);
 	psi_memstall_enter(&pflags);
-	__fs_reclaim_acquire();
+	__fs_reclaim_acquire(_THIS_IP_);
 
 	count_vm_event(PAGEOUTRUN);
 
@@ -3938,9 +3938,9 @@ restart:
 			wake_up_all(&pgdat->pfmemalloc_wait);
 
 		/* Check if kswapd should be suspending */
-		__fs_reclaim_release();
+		__fs_reclaim_release(_THIS_IP_);
 		ret = try_to_freeze();
-		__fs_reclaim_acquire();
+		__fs_reclaim_acquire(_THIS_IP_);
 		if (ret || kthread_should_stop())
 			break;
 
@@ -3992,7 +3992,7 @@ out:
 	}
 
 	snapshot_refaults(NULL, pgdat);
-	__fs_reclaim_release();
+	__fs_reclaim_release(_THIS_IP_);
 	psi_memstall_leave(&pflags);
 	set_task_reclaim_state(current, NULL);