[1/3] xfs: add kmem allocation trace points

Commit Message

Dave Chinner Aug. 26, 2019, 1:40 a.m. UTC

From: Dave Chinner <[e-mail]>

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 <[e-mail]>
Reviewed-by: Brian Foster <[e-mail]>
---
 fs/xfs/kmem.c             | 11 +++++++++--
 fs/xfs/libxfs/xfs_types.h |  8 ++++++++
 fs/xfs/xfs_mount.h        |  7 -------
 fs/xfs/xfs_trace.h        | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 50 insertions(+), 9 deletions(-)

Comments

Christoph Hellwig Aug. 26, 2019, 7:47 a.m. UTC | #1

On Mon, Aug 26, 2019 at 11:40:05AM +1000, Dave Chinner wrote:
> From: Dave Chinner <[e-mail]>
> 
> 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 <[e-mail]>
> Reviewed-by: Brian Foster <[e-mail]>

Looks good, although I'd still prefer the AG enum move in a separate
prep patch:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index 16bb9a328678..0a78ef0588f9 100644
--- a/fs/xfs/kmem.c
+++ b/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|KM_NOSLEEP)))
@@ -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|KM_NOSLEEP)))
@@ -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|KM_NOSLEEP)))
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index 802b34cd10fe..300b3e91ca3a 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/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
  */
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 4adb6837439a..fdb60e09a9c5 100644
--- a/fs/xfs/xfs_mount.h
+++ b/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;
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 8094b1920eef..8bb8b4704a00 100644
--- a/fs/xfs/xfs_trace.h
+++ b/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