1instrument(3) Erlang Module Definition instrument(3)
2
6 instrument - Analysis and Utility Functions for Instrumentation
7
9 The module instrument contains support for studying the resource usage
10 in an Erlang runtime system. Currently, only the allocation of memory
11 can be studied.
12 Note:
14 Note that this whole module is experimental, and the representations
15 used as well as the functionality is likely to change in the future.
16
19 block_histogram() = tuple()
20 A histogram of block sizes where each interval's upper bound is
22 twice as high as the one before it.
23 The upper bound of the first interval is provided by the func‐
25 tion that returned the histogram, and the last interval has no
26 upper bound.
27 allocation_summary() =
29 {HistogramStart :: integer() >= 0,
30 UnscannedSize :: integer() >= 0,
31 Allocations ::
32 #{Origin :: atom() =>
33 #{Type :: atom() => block_histogram()}}}
34 A summary of allocated block sizes (including their headers)
36 grouped by their Origin and Type.
37 Origin is generally which NIF or driver that allocated the
39 blocks, or 'system' if it could not be determined.
40 Type is the allocation category that the blocks belong to, e.g.
42 db_term, message or binary.
43 If one or more carriers could not be scanned in full without
45 harming the responsiveness of the system, UnscannedSize is the
46 number of bytes that had to be skipped.
47 carrier_info_list() =
49 {HistogramStart :: integer() >= 0,
50 Carriers ::
51 [{AllocatorType :: atom(),
52 TotalSize :: integer() >= 0,
53 UnscannedSize :: integer() >= 0,
54 AllocatedSize :: integer() >= 0,
55 AllocatedCount :: integer() >= 0,
56 InPool :: boolean(),
57 FreeBlocks :: block_histogram()}]}
58 AllocatorType is the type of the allocator that employs this
60 carrier.
61 TotalSize is the total size of the carrier, including its
63 header.
64 AllocatedSize is the combined size of the carrier's allocated
66 blocks, including their headers.
67 AllocatedCount is the number of allocated blocks in the carrier.
69 InPool is whether the carrier is in the migration pool.
71 FreeBlocks is a histogram of the free block sizes in the car‐
73 rier.
74 If the carrier could not be scanned in full without harming the
76 responsiveness of the system, UnscannedSize is the number of
77 bytes that had to be skipped.
78
80 allocations() -> {ok, Result} | {error, Reason}
81 Types:
83 Result = allocation_summary()
85 Reason = not_enabled
86 Shorthand for allocations(#{}).
88 allocations(Options) -> {ok, Result} | {error, Reason}
90 Types:
92 Result = allocation_summary()
94 Reason = not_enabled
95 Options =
96 #{scheduler_ids => [integer() >= 0],
97 allocator_types => [atom()],
98 histogram_start => integer() >= 1,
99 histogram_width => integer() >= 1}
100 Returns a summary of all tagged allocations in the system,
102 optionally filtered by allocator type and scheduler id.
103 Only binaries and allocations made by NIFs and drivers are
105 tagged by default, but this can be configured an a per-allocator
106 basis with the +M<S>atags emulator option.
107 If tagged allocations are not enabled on any of the specified
109 allocator types, the call will fail with {error, not_enabled}.
110 The following options can be used:
112 allocator_types:
114 The allocator types that will be searched. Defaults to all
115 alloc_util allocators.
116 scheduler_ids:
118 The scheduler ids whose allocator instances will be
119 searched. A scheduler id of 0 will refer to the global
120 instance that is not tied to any particular scheduler.
121 Defaults to all schedulers and the global instance.
122 histogram_start:
124 The upper bound of the first interval in the allocated block
125 size histograms. Defaults to 128.
126 histogram_width:
128 The number of intervals in the allocated block size his‐
129 tograms. Defaults to 18.
130 Example:
132 > instrument:allocations(#{ histogram_start => 128, histogram_width => 15 }).
134 {ok,{128,0,
135 #{udp_inet =>
136 #{driver_event_state => {0,0,0,0,0,0,0,0,0,1,0,0,0,0,0}},
137 system =>
138 #{heap => {0,0,0,0,20,4,2,2,2,3,0,1,0,0,1},
139 db_term => {271,3,1,52,80,1,0,0,0,0,0,0,0,0,0},
140 code => {0,0,0,5,3,6,11,22,19,20,10,2,1,0,0},
141 binary => {18,0,0,0,7,0,0,1,0,0,0,0,0,0,0},
142 message => {0,40,78,2,2,0,0,0,0,0,0,0,0,0,0},
143 ... }
144 spawn_forker =>
145 #{driver_select_data_state =>
146 {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},
147 ram_file_drv => #{drv_binary => {0,0,0,0,0,0,1,0,0,0,0,0,0,0,0}},
148 prim_file =>
149 #{process_specific_data => {2,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
150 nif_trap_export_entry => {0,4,0,0,0,0,0,0,0,0,0,0,0,0,0},
151 monitor_extended => {0,1,0,0,0,0,0,0,0,0,0,0,0,0,0},
152 drv_binary => {0,0,0,0,0,0,1,0,3,5,0,0,0,1,0},
153 binary => {0,4,0,0,0,0,0,0,0,0,0,0,0,0,0}},
154 prim_buffer =>
155 #{nif_internal => {0,4,0,0,0,0,0,0,0,0,0,0,0,0,0},
156 binary => {0,4,0,0,0,0,0,0,0,0,0,0,0,0,0}}}}}
157 carriers() -> {ok, Result} | {error, Reason}
160 Types:
162 Result = carrier_info_list()
164 Reason = not_enabled
165 Shorthand for carriers(#{}).
167 carriers(Options) -> {ok, Result} | {error, Reason}
169 Types:
171 Result = carrier_info_list()
173 Reason = not_enabled
174 Options =
175 #{scheduler_ids => [integer() >= 0],
176 allocator_types => [atom()],
177 histogram_start => integer() >= 1,
178 histogram_width => integer() >= 1}
179 Returns a summary of all carriers in the system, optionally fil‐
181 tered by allocator type and scheduler id.
182 If the specified allocator types are not enabled, the call will
184 fail with {error, not_enabled}.
185 The following options can be used:
187 allocator_types:
189 The allocator types that will be searched. Defaults to all
190 alloc_util allocators.
191 scheduler_ids:
193 The scheduler ids whose allocator instances will be
194 searched. A scheduler id of 0 will refer to the global
195 instance that is not tied to any particular scheduler.
196 Defaults to all schedulers and the global instance.
197 histogram_start:
199 The upper bound of the first interval in the free block size
200 histograms. Defaults to 512.
201 histogram_width:
203 The number of intervals in the free block size histograms.
204 Defaults to 14.
205 Example:
207 > instrument:carriers(#{ histogram_start => 512, histogram_width => 8 }).
209 {ok,{512,
210 [{ll_alloc,1048576,0,1048344,71,false,{0,0,0,0,0,0,0,0}},
211 {binary_alloc,1048576,0,324640,13,false,{3,0,0,1,0,0,0,2}},
212 {eheap_alloc,2097152,0,1037200,45,false,{2,1,1,3,4,3,2,2}},
213 {fix_alloc,32768,0,29544,82,false,{22,0,0,0,0,0,0,0}},
214 {...}|...]}}
215
218 erts_alloc(3), erl(1)
219Ericsson AB tools 3.1.0.1 instrument(3)