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[WIP DNM] linux/sysfs: use opendir() to list cpu caches #629

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[WIP DNM] linux/sysfs: use opendir() to list cpu caches #629

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08ccb1c
tests/linux/gather: ignore gp_index/obj IDs
bgoglin Oct 20, 2023
ac86c4f
WIP linux/sysfs: use opendir() to list cpu caches
bgoglin Oct 20, 2023
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27 changes: 18 additions & 9 deletions hwloc/topology-linux.c
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Expand Up @@ -5032,11 +5032,18 @@ look_sysfscpu(struct hwloc_topology *topology,

/* look at the caches */
if (topology->want_some_cpu_caches) {
for(j=0; j<10; j++) {
DIR *cachesdir;
struct dirent *dirent;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/", i);
cachesdir = hwloc_opendir(str, data->root_fd);
if (cachesdir) {
while ((dirent = readdir(cachesdir)) != NULL) {
char str2[20]; /* enough for a level number (one digit) or a type (Data/Instruction/Unified) */
hwloc_bitmap_t cacheset;

sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/shared_cpu_map", i, j);
if (strncmp(dirent->d_name, "index", 5))
continue;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/shared_cpu_map", i, dirent->d_name);
cacheset = hwloc__alloc_read_path_as_cpumask(str, data->root_fd);
if (cacheset) {
if (hwloc_bitmap_iszero(cacheset)) {
Expand Down Expand Up @@ -5066,14 +5073,14 @@ look_sysfscpu(struct hwloc_topology *topology,
struct hwloc_obj *cache;

/* get the cache level depth */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/level", i, j); /* contains %u at least up to 4.19 */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/level", i, dirent->d_name); /* contains %u at least up to 4.19 */
if (hwloc_read_path_as_uint(str, &depth, data->root_fd) < 0) {
hwloc_bitmap_free(cacheset);
continue;
}

/* cache type */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/type", i, j);
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/type", i, dirent->d_name);
if (hwloc_read_path_by_length(str, str2, sizeof(str2), data->root_fd) > 0) {
if (!strncmp(str2, "Data", 4))
ctype = HWLOC_OBJ_CACHE_DATA;
Expand All @@ -5084,7 +5091,7 @@ look_sysfscpu(struct hwloc_topology *topology,
}

/* cache id */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/id", i, j);
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/id", i, dirent->d_name);
hwloc_read_path_as_uint(str, &id, data->root_fd);

otype = hwloc_cache_type_by_depth_type(depth, ctype);
Expand All @@ -5099,7 +5106,7 @@ look_sysfscpu(struct hwloc_topology *topology,

/* get the cache size */
kB = 0;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/size", i, j); /* contains %uK at least up to 4.19 */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/size", i, dirent->d_name); /* contains %uK at least up to 4.19 */
hwloc_read_path_as_uint(str, &kB, data->root_fd);
/* KNL reports L3 with size=0 and full cpuset in cpuid.
* Let hwloc_linux_try_add_knl_mcdram_cache() detect it better.
Expand All @@ -5111,19 +5118,19 @@ look_sysfscpu(struct hwloc_topology *topology,

/* get the line size */
linesize = 0;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/coherency_line_size", i, j); /* contains %u at least up to 4.19 */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/coherency_line_size", i, dirent->d_name); /* contains %u at least up to 4.19 */
hwloc_read_path_as_uint(str, &linesize, data->root_fd);

/* get the number of sets and lines per tag.
* don't take the associativity directly in "ways_of_associativity" because
* some archs (ia64, ppc) put 0 there when fully-associative, while others (x86) put something like -1 there.
*/
sets = 0;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/number_of_sets", i, j); /* contains %u at least up to 4.19 */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/number_of_sets", i, dirent->d_name); /* contains %u at least up to 4.19 */
hwloc_read_path_as_uint(str, &sets, data->root_fd);

lines_per_tag = 1;
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/index%d/physical_line_partition", i, j); /* contains %u at least up to 4.19 */
sprintf(str, "/sys/devices/system/cpu/cpu%d/cache/%s/physical_line_partition", i, dirent->d_name); /* contains %u at least up to 4.19 */
hwloc_read_path_as_uint(str, &lines_per_tag, data->root_fd);

/* first cpu in this cache, add the cache */
Expand All @@ -5147,6 +5154,8 @@ look_sysfscpu(struct hwloc_topology *topology,
}
hwloc_bitmap_free(cacheset);
}
closedir(cachesdir);
}
}

} hwloc_bitmap_foreach_end();
Expand Down
11 changes: 9 additions & 2 deletions tests/hwloc/linux/gather/test-gather-topology.sh.in
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Expand Up @@ -62,7 +62,11 @@ export HWLOC_FSROOT=//

echo "Saving current system topology to XML..."
# ignore DAXDevice info attr because it won't appear in save2.xml unless we pass --io to gather below
if ! "$lstopo" --no-io -.xml | grep -v DAXDevice > "$tmpdir/save1.xml" ; then
if ! "$lstopo" --no-io -.xml \
| sed -e 's/ id="obj[0-9]*"//' \
| sed -e 's/ gp_index="[0-9]*"//' \
| grep -v DAXDevice \
> "$tmpdir/save1.xml" ; then
error "Failed"
exit 1
fi
Expand All @@ -85,7 +89,10 @@ export HWLOC_FSROOT="$tmpdir/save"
rm -f "$tmpdir/save/proc/hwloc-nofile-info"

echo "Saving tarball topology to XML..."
if ! "$lstopo" --no-io "$tmpdir/save2.xml" ; then
if ! "$lstopo" --no-io -.xml \
| sed -e 's/ id="obj[0-9]*"//' \
| sed -e 's/ gp_index="[0-9]*"//' \
> "$tmpdir/save2.xml" ; then
error "Failed"
exit 1
fi
Expand Down