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kswiecickikswiecicki
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Add memspace "lowest latency"
This memspace is analogous to the 'highest bandwidth' memspace in its composition, but it focuses on the NUMA nodes with best latency.
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10 files changed

+209
-13
lines changed

10 files changed

+209
-13
lines changed

‎include/umf/memspace.h‎

Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -61,6 +61,11 @@ umf_memspace_handle_t umfMemspaceHighestCapacityGet(void);
6161
///
6262
umf_memspace_handle_t umfMemspaceHighestBandwidthGet(void);
6363

64+
/// \brief Retrieves predefined lowest latency memspace.
65+
/// \return lowest latency memspace handle on success or NULL on failure.
66+
///
67+
umf_memspace_handle_t umfMemspaceLowestLatencyGet(void);
68+
6469
#ifdef __cplusplus
6570
}
6671
#endif

‎src/CMakeLists.txt‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -84,7 +84,8 @@ set(UMF_SOURCES_COMMON_LINUX_MACOSX
8484
memspaces/memspace_numa.c
8585
memspaces/memspace_host_all.c
8686
memspaces/memspace_highest_capacity.c
87-
memspaces/memspace_highest_bandwidth.c)
87+
memspaces/memspace_highest_bandwidth.c
88+
memspaces/memspace_lowest_latency.c)
8889

8990
set(UMF_SOURCES_LINUX ${UMF_SOURCES_LINUX} ${UMF_SOURCES_COMMON_LINUX_MACOSX}
9091
provider/provider_os_memory_linux.c)

‎src/libumf.map‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -36,6 +36,7 @@ UMF_1.0 {
3636
umfMemspaceHighestBandwidthGet;
3737
umfMemspaceHighestCapacityGet;
3838
umfMemspaceHostAllGet;
39+
umfMemspaceLowestLatencyGet;
3940
umfOpenIPCHandle;
4041
umfOsMemoryProviderOps;
4142
umfPoolAlignedMalloc;

‎src/libumf_linux.c‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -30,6 +30,7 @@ void __attribute__((destructor)) umfDestroy(void) {
3030
umfMemspaceHostAllDestroy();
3131
umfMemspaceHighestCapacityDestroy();
3232
umfMemspaceHighestBandwidthDestroy();
33+
umfMemspaceLowestLatencyDestroy();
3334
umfDestroyTopology();
3435
}
3536

‎src/memory_target.c‎

Lines changed: 12 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -97,3 +97,15 @@ umfMemoryTargetGetBandwidth(umf_memory_target_handle_t srcMemoryTarget,
9797
return srcMemoryTarget->ops->get_bandwidth(
9898
srcMemoryTarget->priv, dstMemoryTarget->priv, bandwidth);
9999
}
100+
101+
umf_result_t
102+
umfMemoryTargetGetLatency(umf_memory_target_handle_t srcMemoryTarget,
103+
umf_memory_target_handle_t dstMemoryTarget,
104+
size_t *latency) {
105+
if (!srcMemoryTarget || !dstMemoryTarget || !latency) {
106+
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
107+
}
108+
109+
return srcMemoryTarget->ops->get_latency(srcMemoryTarget->priv,
110+
dstMemoryTarget->priv, latency);
111+
}

‎src/memory_target.h‎

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -39,6 +39,10 @@ umf_result_t
3939
umfMemoryTargetGetBandwidth(umf_memory_target_handle_t srcMemoryTarget,
4040
umf_memory_target_handle_t dstMemoryTarget,
4141
size_t *bandwidth);
42+
umf_result_t
43+
umfMemoryTargetGetLatency(umf_memory_target_handle_t srcMemoryTarget,
44+
umf_memory_target_handle_t dstMemoryTarget,
45+
size_t *latency);
4246

4347
#ifdef __cplusplus
4448
}

‎src/memory_target_ops.h‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -41,6 +41,8 @@ typedef struct umf_memory_target_ops_t {
4141
umf_result_t (*get_capacity)(void *memoryTarget, size_t *capacity);
4242
umf_result_t (*get_bandwidth)(void *srcMemoryTarget, void *dstMemoryTarget,
4343
size_t *bandwidth);
44+
umf_result_t (*get_latency)(void *srcMemoryTarget, void *dstMemoryTarget,
45+
size_t *latency);
4446
} umf_memory_target_ops_t;
4547

4648
#ifdef __cplusplus

‎src/memory_targets/memory_target_numa.c‎

Lines changed: 78 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -167,13 +167,26 @@ static umf_result_t numa_get_capacity(void *memTarget, size_t *capacity) {
167167
return UMF_RESULT_SUCCESS;
168168
}
169169

170-
static umf_result_t numa_get_bandwidth(void *srcMemoryTarget,
171-
void *dstMemoryTarget,
172-
size_t *bandwidth) {
173-
if (!srcMemoryTarget || !dstMemoryTarget || !bandwidth) {
174-
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
170+
typedef enum memattr_type {
171+
MEMATTR_TYPE_BANDWIDTH,
172+
MEMATTR_TYPE_LATENCY
173+
} memattr_type;
174+
175+
static size_t memattr_get_worst_value(memattr_type type) {
176+
switch (type) {
177+
case MEMATTR_TYPE_BANDWIDTH:
178+
return 0;
179+
case MEMATTR_TYPE_LATENCY:
180+
return SIZE_MAX;
181+
default:
182+
assert(0); // Should not be reachable
183+
return 0;
175184
}
185+
}
176186

187+
static umf_result_t query_attribute_value(void *srcMemoryTarget,
188+
void *dstMemoryTarget, size_t *value,
189+
memattr_type type) {
177190
hwloc_topology_t topology = umfGetTopology();
178191
if (!topology) {
179192
return UMF_RESULT_ERROR_NOT_SUPPORTED;
@@ -195,23 +208,75 @@ static umf_result_t numa_get_bandwidth(void *srcMemoryTarget,
195208

196209
// Given NUMA nodes aren't local, HWLOC returns an error in such case.
197210
if (!hwloc_bitmap_intersects(srcNumaNode->cpuset, dstNumaNode->cpuset)) {
198-
*bandwidth = 0;
211+
// Since we want to skip such query, we return the worst possible
212+
// value for given memory attribute.
213+
*value = memattr_get_worst_value(type);
199214
return UMF_RESULT_SUCCESS;
200215
}
201216

217+
enum hwloc_memattr_id_e hwlocMemAttrType = INT_MAX;
218+
switch (type) {
219+
case MEMATTR_TYPE_BANDWIDTH:
220+
hwlocMemAttrType = HWLOC_MEMATTR_ID_BANDWIDTH;
221+
break;
222+
case MEMATTR_TYPE_LATENCY:
223+
hwlocMemAttrType = HWLOC_MEMATTR_ID_LATENCY;
224+
break;
225+
default:
226+
assert(0); // Shouldn't be reachable.
227+
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
228+
}
229+
202230
struct hwloc_location initiator = {.location.cpuset = srcNumaNode->cpuset,
203231
.type = HWLOC_LOCATION_TYPE_CPUSET};
204-
hwloc_uint64_t value = 0;
205-
int ret = hwloc_memattr_get_value(topology, HWLOC_MEMATTR_ID_BANDWIDTH,
206-
dstNumaNode, &initiator, 0, &value);
232+
233+
hwloc_uint64_t memAttrValue = 0;
234+
int ret = hwloc_memattr_get_value(topology, hwlocMemAttrType, dstNumaNode,
235+
&initiator, 0, &memAttrValue);
207236
if (ret) {
208-
LOG_ERR("Retrieving bandwidth for initiator node %u to node %u failed.",
209-
srcNumaNode->os_index, dstNumaNode->os_index);
210237
return (errno == EINVAL) ? UMF_RESULT_ERROR_NOT_SUPPORTED
211238
: UMF_RESULT_ERROR_UNKNOWN;
212239
}
213240

214-
*bandwidth = value;
241+
*value = memAttrValue;
242+
243+
return UMF_RESULT_SUCCESS;
244+
}
245+
246+
static umf_result_t numa_get_bandwidth(void *srcMemoryTarget,
247+
void *dstMemoryTarget,
248+
size_t *bandwidth) {
249+
if (!srcMemoryTarget || !dstMemoryTarget || !bandwidth) {
250+
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
251+
}
252+
253+
umf_result_t ret = query_attribute_value(srcMemoryTarget, dstMemoryTarget,
254+
bandwidth, MEMATTR_TYPE_BANDWIDTH);
255+
if (ret) {
256+
LOG_ERR("Retrieving bandwidth for initiator node %u to node %u failed.",
257+
((struct numa_memory_target_t *)srcMemoryTarget)->physical_id,
258+
((struct numa_memory_target_t *)dstMemoryTarget)->physical_id);
259+
return ret;
260+
}
261+
262+
return UMF_RESULT_SUCCESS;
263+
}
264+
265+
static umf_result_t numa_get_latency(void *srcMemoryTarget,
266+
void *dstMemoryTarget, size_t *latency) {
267+
if (!srcMemoryTarget || !dstMemoryTarget || !latency) {
268+
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
269+
}
270+
271+
umf_result_t ret = query_attribute_value(srcMemoryTarget, dstMemoryTarget,
272+
latency, MEMATTR_TYPE_LATENCY);
273+
if (ret) {
274+
LOG_ERR("Retrieving latency for initiator node %u to node %u failed.",
275+
((struct numa_memory_target_t *)srcMemoryTarget)->physical_id,
276+
((struct numa_memory_target_t *)dstMemoryTarget)->physical_id);
277+
return ret;
278+
}
279+
215280
return UMF_RESULT_SUCCESS;
216281
}
217282

@@ -223,5 +288,6 @@ struct umf_memory_target_ops_t UMF_MEMORY_TARGET_NUMA_OPS = {
223288
.clone = numa_clone,
224289
.get_capacity = numa_get_capacity,
225290
.get_bandwidth = numa_get_bandwidth,
291+
.get_latency = numa_get_latency,
226292
.memory_provider_create_from_memspace =
227293
numa_memory_provider_create_from_memspace};

‎src/memspace_internal.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -60,6 +60,7 @@ void umfMemspaceDestroy(umf_memspace_handle_t hMemspace);
6060
void umfMemspaceHostAllDestroy(void);
6161
void umfMemspaceHighestCapacityDestroy(void);
6262
void umfMemspaceHighestBandwidthDestroy(void);
63+
void umfMemspaceLowestLatencyDestroy(void);
6364

6465
#ifdef __cplusplus
6566
}

‎src/memspaces/memspace_lowest_latency.c‎

Lines changed: 103 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,103 @@
1+
/*
2+
*
3+
* Copyright (C) 2024 Intel Corporation
4+
*
5+
* Under the Apache License v2.0 with LLVM Exceptions. See LICENSE.TXT.
6+
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7+
*
8+
*/
9+
10+
#include <assert.h>
11+
#include <ctype.h>
12+
#include <hwloc.h>
13+
#include <stdlib.h>
14+
15+
#include "base_alloc_global.h"
16+
#include "memory_target_numa.h"
17+
#include "memspace_internal.h"
18+
#include "memspace_numa.h"
19+
#include "topology.h"
20+
#include "utils_common.h"
21+
#include "utils_concurrency.h"
22+
#include "utils_log.h"
23+
24+
static umf_result_t getBestLatencyTarget(umf_memory_target_handle_t initiator,
25+
umf_memory_target_handle_t *nodes,
26+
size_t numNodes,
27+
umf_memory_target_handle_t *target) {
28+
size_t bestNodeIdx = 0;
29+
size_t bestLatency = SIZE_MAX;
30+
for (size_t nodeIdx = 0; nodeIdx < numNodes; nodeIdx++) {
31+
size_t latency = SIZE_MAX;
32+
umf_result_t ret =
33+
umfMemoryTargetGetLatency(initiator, nodes[nodeIdx], &latency);
34+
if (ret) {
35+
return ret;
36+
}
37+
38+
if (latency < bestLatency) {
39+
bestNodeIdx = nodeIdx;
40+
bestLatency = latency;
41+
}
42+
}
43+
44+
*target = nodes[bestNodeIdx];
45+
46+
return UMF_RESULT_SUCCESS;
47+
}
48+
49+
static umf_result_t
50+
umfMemspaceLowestLatencyCreate(umf_memspace_handle_t *hMemspace) {
51+
if (!hMemspace) {
52+
return UMF_RESULT_ERROR_INVALID_ARGUMENT;
53+
}
54+
55+
umf_memspace_handle_t hostAllMemspace = umfMemspaceHostAllGet();
56+
if (!hostAllMemspace) {
57+
return UMF_RESULT_ERROR_UNKNOWN;
58+
}
59+
60+
umf_memspace_handle_t lowLatencyMemspace = NULL;
61+
umf_result_t ret = umfMemspaceFilter(hostAllMemspace, getBestLatencyTarget,
62+
&lowLatencyMemspace);
63+
if (ret != UMF_RESULT_SUCCESS) {
64+
// HWLOC could possibly return an 'EINVAL' error, which in this context
65+
// means that the HMAT is unavailable and we can't obtain the
66+
// 'latency' value of any NUMA node.
67+
return ret;
68+
}
69+
70+
*hMemspace = lowLatencyMemspace;
71+
return UMF_RESULT_SUCCESS;
72+
}
73+
74+
static umf_memspace_handle_t UMF_MEMSPACE_LOWEST_LATENCY = NULL;
75+
static UTIL_ONCE_FLAG UMF_MEMSPACE_LOWEST_LATENCY_INITIALIZED =
76+
UTIL_ONCE_FLAG_INIT;
77+
78+
void umfMemspaceLowestLatencyDestroy(void) {
79+
if (UMF_MEMSPACE_LOWEST_LATENCY) {
80+
umfMemspaceDestroy(UMF_MEMSPACE_LOWEST_LATENCY);
81+
UMF_MEMSPACE_LOWEST_LATENCY = NULL;
82+
}
83+
}
84+
85+
static void umfMemspaceLowestLatencyInit(void) {
86+
umf_result_t ret =
87+
umfMemspaceLowestLatencyCreate(&UMF_MEMSPACE_LOWEST_LATENCY);
88+
if (ret != UMF_RESULT_SUCCESS) {
89+
LOG_ERR("Creating the lowest latency memspace failed with a %u error\n",
90+
ret);
91+
assert(ret == UMF_RESULT_ERROR_NOT_SUPPORTED);
92+
}
93+
94+
#if defined(_WIN32) && !defined(UMF_SHARED_LIBRARY)
95+
atexit(umfMemspaceLowestLatencyDestroy);
96+
#endif
97+
}
98+
99+
umf_memspace_handle_t umfMemspaceLowestLatencyGet(void) {
100+
util_init_once(&UMF_MEMSPACE_LOWEST_LATENCY_INITIALIZED,
101+
umfMemspaceLowestLatencyInit);
102+
return UMF_MEMSPACE_LOWEST_LATENCY;
103+
}

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