[PATCH 12/12] xfs: trace what memory backs a buffer

[Christoph Hellwig <hch@xxxxxx>]

Add three trace points for the different backing memory allocators for
buffers.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/xfs/xfs_buf.c   | 4 ++++
 fs/xfs/xfs_trace.h | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 0393dd302cf6..a396b628e9b0 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -299,6 +299,7 @@ xfs_buf_alloc_kmem(
 		return -ENOMEM;
 	}
 	bp->b_flags |= _XBF_KMEM;
+	trace_xfs_buf_backing_kmem(bp, _RET_IP_);
 	return 0;
 }
 
@@ -379,9 +380,11 @@ xfs_buf_alloc_backing_mem(
 	if (!folio) {
 		if (size <= PAGE_SIZE)
 			return -ENOMEM;
+		trace_xfs_buf_backing_fallback(bp, _RET_IP_);
 		goto fallback;
 	}
 	bp->b_addr = folio_address(folio);
+	trace_xfs_buf_backing_folio(bp, _RET_IP_);
 	return 0;
 
 fallback:
@@ -395,6 +398,7 @@ xfs_buf_alloc_backing_mem(
 		memalloc_retry_wait(gfp_mask);
 	}
 
+	trace_xfs_buf_backing_vmalloc(bp, _RET_IP_);
 	return 0;
 }
 
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index b29462363b81..c8f64daf6d75 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -545,6 +545,10 @@ DEFINE_BUF_EVENT(xfs_buf_iodone_async);
 DEFINE_BUF_EVENT(xfs_buf_error_relse);
 DEFINE_BUF_EVENT(xfs_buf_drain_buftarg);
 DEFINE_BUF_EVENT(xfs_trans_read_buf_shut);
+DEFINE_BUF_EVENT(xfs_buf_backing_folio);
+DEFINE_BUF_EVENT(xfs_buf_backing_kmem);
+DEFINE_BUF_EVENT(xfs_buf_backing_vmalloc);
+DEFINE_BUF_EVENT(xfs_buf_backing_fallback);
 
 /* not really buffer traces, but the buf provides useful information */
 DEFINE_BUF_EVENT(xfs_btree_corrupt);
-- 
2.45.2