xfs: add kmem allocation trace points

When trying to correlate XFS kernel allocations to memory reclaim
behaviour, it is useful to know what allocations XFS is actually
attempting. This information is not directly available from
tracepoints in the generic memory allocation and reclaim
tracepoints, so these new trace points provide a high level
indication of what the XFS memory demand actually is.

There is no per-filesystem context in this code, so we just trace
the type of allocation, the size and the allocation constraints.
The kmem code also doesn't include much of the common XFS headers,
so there are a few definitions that need to be added to the trace
headers and a couple of types that need to be made common to avoid
needing to include the whole world in the kmem code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/kmem.c

@@ -3,10 +3,10 @@
  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  * All Rights Reserved.
  */
-#include <linux/sched/mm.h>
+#include "xfs.h"
 #include <linux/backing-dev.h>
-#include "kmem.h"
 #include "xfs_message.h"
+#include "xfs_trace.h"
 
 void *
 kmem_alloc(size_t size, xfs_km_flags_t flags)
@@ -15,6 +15,8 @@ kmem_alloc(size_t size, xfs_km_flags_t flags)
 	gfp_t	lflags = kmem_flags_convert(flags);
 	void	*ptr;
 
+	trace_kmem_alloc(size, flags, _RET_IP_);
+
 	do {
 		ptr = kmalloc(size, lflags);
 		if (ptr || (flags & KM_MAYFAIL))
@@ -35,6 +37,8 @@ kmem_alloc_large(size_t size, xfs_km_flags_t flags)
 	void	*ptr;
 	gfp_t	lflags;
 
+	trace_kmem_alloc_large(size, flags, _RET_IP_);
+
 	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
 	if (ptr)
 		return ptr;
@@ -65,6 +69,8 @@ kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
 	gfp_t	lflags = kmem_flags_convert(flags);
 	void	*ptr;
 
+	trace_kmem_realloc(newsize, flags, _RET_IP_);
+
 	do {
 		ptr = krealloc(old, newsize, lflags);
 		if (ptr || (flags & KM_MAYFAIL))
@@ -85,6 +91,7 @@ kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
 	gfp_t	lflags = kmem_flags_convert(flags);
 	void	*ptr;
 
+	trace_kmem_zone_alloc(kmem_cache_size(zone), flags, _RET_IP_);
 	do {
 		ptr = kmem_cache_alloc(zone, lflags);
 		if (ptr || (flags & KM_MAYFAIL))

fs/xfs/libxfs/xfs_types.h

@@ -169,6 +169,14 @@ typedef struct xfs_bmbt_irec
 	xfs_exntst_t	br_state;	/* extent state */
 } xfs_bmbt_irec_t;
 
+/* per-AG block reservation types */
+enum xfs_ag_resv_type {
+	XFS_AG_RESV_NONE = 0,
+	XFS_AG_RESV_AGFL,
+	XFS_AG_RESV_METADATA,
+	XFS_AG_RESV_RMAPBT,
+};
+
 /*
  * Type verifier functions
  */

fs/xfs/xfs_mount.h

@@ -327,13 +327,6 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d)
 }
 
 /* per-AG block reservation data structures*/
-enum xfs_ag_resv_type {
-	XFS_AG_RESV_NONE = 0,
-	XFS_AG_RESV_AGFL,
-	XFS_AG_RESV_METADATA,
-	XFS_AG_RESV_RMAPBT,
-};
-
 struct xfs_ag_resv {
 	/* number of blocks originally reserved here */
 	xfs_extlen_t			ar_orig_reserved;

fs/xfs/xfs_trace.h

@@ -23,6 +23,7 @@ struct xlog;
 struct xlog_ticket;
 struct xlog_recover;
 struct xlog_recover_item;
+struct xlog_rec_header;
 struct xfs_buf_log_format;
 struct xfs_inode_log_format;
 struct xfs_bmbt_irec;
@@ -30,6 +31,10 @@ struct xfs_btree_cur;
 struct xfs_refcount_irec;
 struct xfs_fsmap;
 struct xfs_rmap_irec;
+struct xfs_icreate_log;
+struct xfs_owner_info;
+struct xfs_trans_res;
+struct xfs_inobt_rec_incore;
 
 DECLARE_EVENT_CLASS(xfs_attr_list_class,
 	TP_PROTO(struct xfs_attr_list_context *ctx),
@@ -3575,6 +3580,34 @@ TRACE_EVENT(xfs_pwork_init,
 		  __entry->nr_threads, __entry->pid)
 )
 
+DECLARE_EVENT_CLASS(xfs_kmem_class,
+	TP_PROTO(ssize_t size, int flags, unsigned long caller_ip),
+	TP_ARGS(size, flags, caller_ip),
+	TP_STRUCT__entry(
+		__field(ssize_t, size)
+		__field(int, flags)
+		__field(unsigned long, caller_ip)
+	),
+	TP_fast_assign(
+		__entry->size = size;
+		__entry->flags = flags;
+		__entry->caller_ip = caller_ip;
+	),
+	TP_printk("size %zd flags 0x%x caller %pS",
+		  __entry->size,
+		  __entry->flags,
+		  (char *)__entry->caller_ip)
+)
+
+#define DEFINE_KMEM_EVENT(name) \
+DEFINE_EVENT(xfs_kmem_class, name, \
+	TP_PROTO(ssize_t size, int flags, unsigned long caller_ip), \
+	TP_ARGS(size, flags, caller_ip))
+DEFINE_KMEM_EVENT(kmem_alloc);
+DEFINE_KMEM_EVENT(kmem_alloc_large);
+DEFINE_KMEM_EVENT(kmem_realloc);
+DEFINE_KMEM_EVENT(kmem_zone_alloc);
+
 #endif /* _TRACE_XFS_H */
 
 #undef TRACE_INCLUDE_PATH