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Commit | Line | Data |
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00e5a55c BS |
1 | From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
2 | Subject: LTTng instrumentation - swap | |
3 | ||
4 | Original patch header: | |
5 | LTTng instrumentation - swap | |
6 | ||
7 | Instrumentation of waits caused by swap activity. Also instrumentation | |
8 | swapon/swapoff events to keep track of active swap partitions. | |
9 | ||
10 | Those tracepoints are used by LTTng. | |
11 | ||
12 | About the performance impact of tracepoints (which is comparable to markers), | |
13 | even without immediate values optimizations, tests done by Hideo Aoki on ia64 | |
14 | show no regression. His test case was using hackbench on a kernel where | |
15 | scheduler instrumentation (about 5 events in code scheduler code) was added. | |
16 | See the "Tracepoints" patch header for performance result detail. | |
17 | ||
18 | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | |
19 | CC: linux-mm@kvack.org | |
20 | CC: Dave Hansen <haveblue@us.ibm.com> | |
21 | CC: Masami Hiramatsu <mhiramat@redhat.com> | |
22 | CC: 'Peter Zijlstra' <peterz@infradead.org> | |
23 | CC: "Frank Ch. Eigler" <fche@redhat.com> | |
24 | CC: 'Ingo Molnar' <mingo@elte.hu> | |
25 | CC: 'Hideo AOKI' <haoki@redhat.com> | |
26 | CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com> | |
27 | CC: 'Steven Rostedt' <rostedt@goodmis.org> | |
28 | CC: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> | |
29 | ||
30 | Acked-by: Jan Blunck <jblunck@suse.de> | |
31 | --- | |
32 | --- | |
33 | include/trace/swap.h | 20 ++++++++++++++++++++ | |
34 | mm/memory.c | 3 +++ | |
35 | mm/page_io.c | 2 ++ | |
36 | mm/swapfile.c | 3 +++ | |
37 | 4 files changed, 28 insertions(+) | |
38 | ||
39 | --- /dev/null | |
40 | +++ b/include/trace/swap.h | |
41 | @@ -0,0 +1,20 @@ | |
42 | +#ifndef _TRACE_SWAP_H | |
43 | +#define _TRACE_SWAP_H | |
44 | + | |
45 | +#include <linux/swap.h> | |
46 | +#include <linux/tracepoint.h> | |
47 | + | |
48 | +DEFINE_TRACE(swap_in, | |
49 | + TPPROTO(struct page *page, swp_entry_t entry), | |
50 | + TPARGS(page, entry)); | |
51 | +DEFINE_TRACE(swap_out, | |
52 | + TPPROTO(struct page *page), | |
53 | + TPARGS(page)); | |
54 | +DEFINE_TRACE(swap_file_open, | |
55 | + TPPROTO(struct file *file, char *filename), | |
56 | + TPARGS(file, filename)); | |
57 | +DEFINE_TRACE(swap_file_close, | |
58 | + TPPROTO(struct file *file), | |
59 | + TPARGS(file)); | |
60 | + | |
61 | +#endif | |
62 | --- a/mm/memory.c | |
63 | +++ b/mm/memory.c | |
64 | @@ -64,6 +64,8 @@ | |
65 | ||
66 | #include "internal.h" | |
67 | ||
68 | +#include <trace/swap.h> | |
69 | + | |
70 | #ifndef CONFIG_NEED_MULTIPLE_NODES | |
71 | /* use the per-pgdat data instead for discontigmem - mbligh */ | |
72 | unsigned long max_mapnr; | |
73 | @@ -2420,6 +2422,7 @@ static int do_swap_page(struct mm_struct | |
74 | /* Had to read the page from swap area: Major fault */ | |
75 | ret = VM_FAULT_MAJOR; | |
76 | count_vm_event(PGMAJFAULT); | |
77 | + trace_swap_in(page, entry); | |
78 | } | |
79 | ||
80 | if (mem_cgroup_charge(page, mm, GFP_KERNEL)) { | |
81 | --- a/mm/page_io.c | |
82 | +++ b/mm/page_io.c | |
83 | @@ -17,6 +17,7 @@ | |
84 | #include <linux/bio.h> | |
85 | #include <linux/swapops.h> | |
86 | #include <linux/writeback.h> | |
87 | +#include <trace/swap.h> | |
88 | #include <asm/pgtable.h> | |
89 | ||
90 | static struct bio *get_swap_bio(gfp_t gfp_flags, pgoff_t index, | |
91 | @@ -114,6 +115,7 @@ int swap_writepage(struct page *page, st | |
92 | rw |= (1 << BIO_RW_SYNC); | |
93 | count_vm_event(PSWPOUT); | |
94 | set_page_writeback(page); | |
95 | + trace_swap_out(page); | |
96 | unlock_page(page); | |
97 | submit_bio(rw, bio); | |
98 | out: | |
99 | --- a/mm/swapfile.c | |
100 | +++ b/mm/swapfile.c | |
101 | @@ -36,6 +36,7 @@ | |
102 | #include <asm/pgtable.h> | |
103 | #include <asm/tlbflush.h> | |
104 | #include <linux/swapops.h> | |
105 | +#include <trace/swap.h> | |
106 | ||
107 | static DEFINE_SPINLOCK(swap_lock); | |
108 | static unsigned int nr_swapfiles; | |
109 | @@ -1325,6 +1326,7 @@ SYSCALL_DEFINE1(swapoff, const char __us | |
110 | swap_map = p->swap_map; | |
111 | p->swap_map = NULL; | |
112 | p->flags = 0; | |
113 | + trace_swap_file_close(swap_file); | |
114 | spin_unlock(&swap_lock); | |
115 | mutex_unlock(&swapon_mutex); | |
116 | vfree(swap_map); | |
117 | @@ -1704,6 +1706,7 @@ SYSCALL_DEFINE2(swapon, const char __use | |
118 | } else { | |
119 | swap_info[prev].next = p - swap_info; | |
120 | } | |
121 | + trace_swap_file_open(swap_file, name); | |
122 | spin_unlock(&swap_lock); | |
123 | mutex_unlock(&swapon_mutex); | |
124 | error = 0; |