[RFC V2 07/37] dmem: trace core functions

From: yulei . kernel
Date: Mon Dec 07 2020 - 06:35:26 EST


From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>

Add tracepoints for dmem alloc_init, alloc and free functions,
that helps us to figure out what is happening inside dmem
allocator

Signed-off-by: Xiao Guangrong <gloryxiao@xxxxxxxxxxx>
Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>
---
fs/dmemfs/Makefile | 1 +
fs/dmemfs/inode.c | 5 ++++
fs/dmemfs/trace.h | 54 +++++++++++++++++++++++++++++++++++
include/trace/events/dmem.h | 68 +++++++++++++++++++++++++++++++++++++++++++++
mm/dmem.c | 6 ++++
5 files changed, 134 insertions(+)
create mode 100644 fs/dmemfs/trace.h
create mode 100644 include/trace/events/dmem.h

diff --git a/fs/dmemfs/Makefile b/fs/dmemfs/Makefile
index 73bdc9c..0b36d03 100644
--- a/fs/dmemfs/Makefile
+++ b/fs/dmemfs/Makefile
@@ -2,6 +2,7 @@
#
# Makefile for the linux dmem-filesystem routines.
#
+ccflags-y += -I $(srctree)/$(src) # needed for trace events
obj-$(CONFIG_DMEM_FS) += dmemfs.o

dmemfs-y += inode.o
diff --git a/fs/dmemfs/inode.c b/fs/dmemfs/inode.c
index 9ec62dc..7723b58 100644
--- a/fs/dmemfs/inode.c
+++ b/fs/dmemfs/inode.c
@@ -31,6 +31,9 @@
MODULE_AUTHOR("Tencent Corporation");
MODULE_LICENSE("GPL v2");

+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
struct dmemfs_mount_opts {
unsigned long dpage_size;
};
@@ -336,6 +339,7 @@ static void *find_radix_entry_or_next(struct address_space *mapping,
offset += inode->i_sb->s_blocksize;
dpages--;
mapping->nrexceptional++;
+ trace_dmemfs_radix_tree_insert(index, entry);
index++;
}

@@ -532,6 +536,7 @@ static void inode_drop_dpages(struct inode *inode, loff_t start, loff_t end)
break;

xa_erase(&mapping->i_pages, istart);
+ trace_dmemfs_radix_tree_delete(istart, pvec.pages[i]);
mapping->nrexceptional--;

addr = dmem_entry_to_addr(inode, pvec.pages[i]);
diff --git a/fs/dmemfs/trace.h b/fs/dmemfs/trace.h
new file mode 100644
index 00000000..cc11653
--- /dev/null
+++ b/fs/dmemfs/trace.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * trace.h - DesignWare Support
+ *
+ * Copyright (C)
+ *
+ * Author: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx>
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dmemfs
+
+#if !defined(_TRACE_DMEMFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DMEMFS_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(dmemfs_radix_tree_class,
+ TP_PROTO(unsigned long index, void *rentry),
+ TP_ARGS(index, rentry),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, index)
+ __field(void *, rentry)
+ ),
+
+ TP_fast_assign(
+ __entry->index = index;
+ __entry->rentry = rentry;
+ ),
+
+ TP_printk("index %lu entry %#lx", __entry->index,
+ (unsigned long)__entry->rentry)
+);
+
+DEFINE_EVENT(dmemfs_radix_tree_class, dmemfs_radix_tree_insert,
+ TP_PROTO(unsigned long index, void *rentry),
+ TP_ARGS(index, rentry)
+);
+
+DEFINE_EVENT(dmemfs_radix_tree_class, dmemfs_radix_tree_delete,
+ TP_PROTO(unsigned long index, void *rentry),
+ TP_ARGS(index, rentry)
+);
+#endif
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/include/trace/events/dmem.h b/include/trace/events/dmem.h
new file mode 100644
index 00000000..10d1b90
--- /dev/null
+++ b/include/trace/events/dmem.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dmem
+
+#if !defined(_TRACE_DMEM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DMEM_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(dmem_alloc_init,
+ TP_PROTO(unsigned long dpage_shift),
+ TP_ARGS(dpage_shift),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, dpage_shift)
+ ),
+
+ TP_fast_assign(
+ __entry->dpage_shift = dpage_shift;
+ ),
+
+ TP_printk("dpage_shift %lu", __entry->dpage_shift)
+);
+
+TRACE_EVENT(dmem_alloc_pages_node,
+ TP_PROTO(phys_addr_t addr, int node, int try_max, int result_nr),
+ TP_ARGS(addr, node, try_max, result_nr),
+
+ TP_STRUCT__entry(
+ __field(phys_addr_t, addr)
+ __field(int, node)
+ __field(int, try_max)
+ __field(int, result_nr)
+ ),
+
+ TP_fast_assign(
+ __entry->addr = addr;
+ __entry->node = node;
+ __entry->try_max = try_max;
+ __entry->result_nr = result_nr;
+ ),
+
+ TP_printk("addr %#lx node %d try_max %d result_nr %d",
+ (unsigned long)__entry->addr, __entry->node,
+ __entry->try_max, __entry->result_nr)
+);
+
+TRACE_EVENT(dmem_free_pages,
+ TP_PROTO(phys_addr_t addr, int dpages_nr),
+ TP_ARGS(addr, dpages_nr),
+
+ TP_STRUCT__entry(
+ __field(phys_addr_t, addr)
+ __field(int, dpages_nr)
+ ),
+
+ TP_fast_assign(
+ __entry->addr = addr;
+ __entry->dpages_nr = dpages_nr;
+ ),
+
+ TP_printk("addr %#lx dpages_nr %d", (unsigned long)__entry->addr,
+ __entry->dpages_nr)
+);
+#endif
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/mm/dmem.c b/mm/dmem.c
index a77a064..aa34bf2 100644
--- a/mm/dmem.c
+++ b/mm/dmem.c
@@ -18,6 +18,8 @@
#include <linux/debugfs.h>
#include <linux/notifier.h>

+#define CREATE_TRACE_POINTS
+#include <trace/events/dmem.h>
/*
* There are two kinds of page in dmem management:
* - nature page, it's the CPU's page size, i.e, 4K on x86
@@ -559,6 +561,8 @@ int dmem_alloc_init(unsigned long dpage_shift)

mutex_lock(&dmem_pool.lock);

+ trace_dmem_alloc_init(dpage_shift);
+
if (dmem_pool.dpage_shift) {
/*
* double init on the same page size is okay
@@ -686,6 +690,7 @@ int dmem_alloc_init(unsigned long dpage_shift)
}
}

+ trace_dmem_alloc_pages_node(addr, node, try_max, *result_nr);
mutex_unlock(&dmem_pool.lock);
}
return addr;
@@ -791,6 +796,7 @@ void dmem_free_pages(phys_addr_t addr, unsigned int dpages_nr)

mutex_lock(&dmem_pool.lock);

+ trace_dmem_free_pages(addr, dpages_nr);
WARN_ON(!dmem_pool.dpage_shift);

dregion = find_dmem_region(addr, &pdnode);
--
1.8.3.1