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Add option to use logical cores for default threads
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Binh Vo committed Jun 16, 2021
1 parent 0152435 commit 93c027e
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Showing 4 changed files with 117 additions and 47 deletions.
134 changes: 89 additions & 45 deletions programs/util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1103,7 +1103,7 @@ FileNamesTable* UTIL_createFNT_fromROTable(const char** filenames, size_t nbFile


/*-****************************************
* count the number of physical cores
* count the number of cores
******************************************/

#if defined(_WIN32) || defined(WIN32)
Expand All @@ -1112,10 +1112,26 @@ FileNamesTable* UTIL_createFNT_fromROTable(const char** filenames, size_t nbFile

typedef BOOL(WINAPI* LPFN_GLPI)(PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);

int UTIL_countPhysicalCores(void)
DWORD CountSetBits(ULONG_PTR bitMask)
{
DWORD LSHIFT = sizeof(ULONG_PTR)*8 - 1;
DWORD bitSetCount = 0;
ULONG_PTR bitTest = (ULONG_PTR)1 << LSHIFT;
DWORD i;

for (i = 0; i <= LSHIFT; ++i)
{
bitSetCount += ((bitMask & bitTest)?1:0);
bitTest/=2;
}

return bitSetCount;
}

int UTIL_countCores(int logical)
{
static int numPhysicalCores = 0;
if (numPhysicalCores != 0) return numPhysicalCores;
static int numCores = 0;
if (numCores != 0) return numCores;

{ LPFN_GLPI glpi;
BOOL done = FALSE;
Expand Down Expand Up @@ -1161,7 +1177,10 @@ int UTIL_countPhysicalCores(void)
while (byteOffset + sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) <= returnLength) {

if (ptr->Relationship == RelationProcessorCore) {
numPhysicalCores++;
if (logical)
numCores += CountSetBits(ptr->ProcessorMask);
else
numCores++;
}

ptr++;
Expand All @@ -1170,17 +1189,17 @@ int UTIL_countPhysicalCores(void)

free(buffer);

return numPhysicalCores;
return numCores;
}

failed:
/* try to fall back on GetSystemInfo */
{ SYSTEM_INFO sysinfo;
GetSystemInfo(&sysinfo);
numPhysicalCores = sysinfo.dwNumberOfProcessors;
if (numPhysicalCores == 0) numPhysicalCores = 1; /* just in case */
numCores = sysinfo.dwNumberOfProcessors;
if (numCores == 0) numCores = 1; /* just in case */
}
return numPhysicalCores;
return numCores;
}

#elif defined(__APPLE__)
Expand All @@ -1189,24 +1208,24 @@ int UTIL_countPhysicalCores(void)

/* Use apple-provided syscall
* see: man 3 sysctl */
int UTIL_countPhysicalCores(void)
int UTIL_countCores(int logical)
{
static S32 numPhysicalCores = 0; /* apple specifies int32_t */
if (numPhysicalCores != 0) return numPhysicalCores;
static S32 numCores = 0; /* apple specifies int32_t */
if (numCores != 0) return numCores;

{ size_t size = sizeof(S32);
int const ret = sysctlbyname("hw.physicalcpu", &numPhysicalCores, &size, NULL, 0);
int const ret = sysctlbyname(logical ? "hw.logicalcpu" : "hw.physicalcpu", &numCores, &size, NULL, 0);
if (ret != 0) {
if (errno == ENOENT) {
/* entry not present, fall back on 1 */
numPhysicalCores = 1;
numCores = 1;
} else {
perror("zstd: can't get number of physical cpus");
perror("zstd: can't get number of cpus");
exit(1);
}
}

return numPhysicalCores;
return numCores;
}
}

Expand All @@ -1215,16 +1234,16 @@ int UTIL_countPhysicalCores(void)
/* parse /proc/cpuinfo
* siblings / cpu cores should give hyperthreading ratio
* otherwise fall back on sysconf */
int UTIL_countPhysicalCores(void)
int UTIL_countCores(int logical)
{
static int numPhysicalCores = 0;
static int numCores = 0;

if (numPhysicalCores != 0) return numPhysicalCores;
if (numCores != 0) return numCores;

numPhysicalCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numPhysicalCores == -1) {
numCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numCores == -1) {
/* value not queryable, fall back on 1 */
return numPhysicalCores = 1;
return numCores = 1;
}

/* try to determine if there's hyperthreading */
Expand All @@ -1238,7 +1257,7 @@ int UTIL_countPhysicalCores(void)

if (cpuinfo == NULL) {
/* fall back on the sysconf value */
return numPhysicalCores;
return numCores;
}

/* assume the cpu cores/siblings values will be constant across all
Expand Down Expand Up @@ -1271,13 +1290,13 @@ int UTIL_countPhysicalCores(void)
ratio = siblings / cpu_cores;
}

if (ratio && numPhysicalCores > ratio) {
numPhysicalCores = numPhysicalCores / ratio;
if (ratio && numCores > ratio && !logical) {
numCores = numCores / ratio;
}

failed:
fclose(cpuinfo);
return numPhysicalCores;
return numCores;
}
}

Expand All @@ -1288,59 +1307,84 @@ int UTIL_countPhysicalCores(void)

/* Use physical core sysctl when available
* see: man 4 smp, man 3 sysctl */
int UTIL_countPhysicalCores(void)
int UTIL_countCores(int logical)
{
static int numPhysicalCores = 0; /* freebsd sysctl is native int sized */
if (numPhysicalCores != 0) return numPhysicalCores;
static int numCores = 0; /* freebsd sysctl is native int sized */
#if __FreeBSD_version >= 1300008
static int perCore = 1;
#endif
if (numCores != 0) return numCores;

#if __FreeBSD_version >= 1300008
{ size_t size = sizeof(numPhysicalCores);
int ret = sysctlbyname("kern.smp.cores", &numPhysicalCores, &size, NULL, 0);
if (ret == 0) return numPhysicalCores;
{ size_t size = sizeof(numCores);
int ret = sysctlbyname("kern.smp.cores", &numCores, &size, NULL, 0);
if (ret == 0) {
if (logical) {
ret = sysctlbyname("kern.smp.threads_per_core", &perCore, &size, NULL, 0);
/* default to physical cores if logical cannot be read */
if (ret == 0)
numCores *= perCore;
}

return numCores;
}
if (errno != ENOENT) {
perror("zstd: can't get number of physical cpus");
perror("zstd: can't get number of cpus");
exit(1);
}
/* sysctl not present, fall through to older sysconf method */
}
#else
/* suppress unused parameter warning */
(void) logical;
#endif

numPhysicalCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numPhysicalCores == -1) {
numCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numCores == -1) {
/* value not queryable, fall back on 1 */
numPhysicalCores = 1;
numCores = 1;
}
return numPhysicalCores;
return numCores;
}

#elif defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__CYGWIN__)

/* Use POSIX sysconf
* see: man 3 sysconf */
int UTIL_countPhysicalCores(void)
int UTIL_countCores(int logical)
{
static int numPhysicalCores = 0;
static int numCores = 0;

if (numPhysicalCores != 0) return numPhysicalCores;
if (numCores != 0) return numCores;

numPhysicalCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numPhysicalCores == -1) {
numCores = (int)sysconf(_SC_NPROCESSORS_ONLN);
if (numCores == -1) {
/* value not queryable, fall back on 1 */
return numPhysicalCores = 1;
return numCores = 1;
}
return numPhysicalCores;
return numCores;
}

#else

int UTIL_countPhysicalCores(void)
int UTIL_countCores(int logical)
{
/* assume 1 */
return 1;
}

#endif

int UTIL_countPhysicalCores(void)
{
return UTIL_countCores(0);
}

int UTIL_countLogicalCores(void)
{
return UTIL_countCores(1);
}

#if defined (__cplusplus)
}
#endif
6 changes: 6 additions & 0 deletions programs/util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -289,13 +289,19 @@ void UTIL_refFilename(FileNamesTable* fnt, const char* filename);
FileNamesTable*
UTIL_createExpandedFNT(const char* const* filenames, size_t nbFilenames, int followLinks);

#if defined(_WIN32) || defined(WIN32)
DWORD CountSetBits(ULONG_PTR bitMask);
#endif

/*-****************************************
* System
******************************************/

int UTIL_countCores(int logical);

int UTIL_countPhysicalCores(void);

int UTIL_countLogicalCores(void);

#if defined (__cplusplus)
}
Expand Down
22 changes: 20 additions & 2 deletions programs/zstdcli.c
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Original file line number Diff line number Diff line change
Expand Up @@ -213,6 +213,7 @@ static void usage_advanced(const char* programName)
DISPLAYOUT( " -T# : spawns # compression threads (default: 1, 0==# cores) \n");
DISPLAYOUT( " -B# : select size of each job (default: 0==automatic) \n");
DISPLAYOUT( "--single-thread : use a single thread for both I/O and compression (result slightly different than -T1) \n");
DISPLAYOUT( "--auto-threads={physical,logical} (default: physical} : use either physical cores or logical cores as default when specifying -T=0 \n");
DISPLAYOUT( "--rsyncable : compress using a rsync-friendly method (-B sets block size) \n");
# endif
DISPLAYOUT( "--exclude-compressed: only compress files that are not already compressed \n");
Expand Down Expand Up @@ -761,6 +762,9 @@ int main(int const argCount, const char* argv[])
separateFiles = 0,
setRealTimePrio = 0,
singleThread = 0,
#ifdef ZSTD_MULTITHREAD
defaultLogicalCores = 0,
#endif
showDefaultCParams = 0,
ultra=0,
contentSize=1;
Expand Down Expand Up @@ -950,6 +954,15 @@ int main(int const argCount, const char* argv[])
if (longCommandWArg(&argument, "--target-compressed-block-size=")) { targetCBlockSize = readSizeTFromChar(&argument); continue; }
if (longCommandWArg(&argument, "--size-hint=")) { srcSizeHint = readSizeTFromChar(&argument); continue; }
if (longCommandWArg(&argument, "--output-dir-flat")) { NEXT_FIELD(outDirName); continue; }
#ifdef ZSTD_MULTITHREAD
if (longCommandWArg(&argument, "--auto-threads")) {
const char* threadDefault = NULL;
NEXT_FIELD(threadDefault);
if (strcmp(threadDefault, "logical") == 0)
defaultLogicalCores = 1;
continue;
}
#endif
#ifdef UTIL_HAS_MIRRORFILELIST
if (longCommandWArg(&argument, "--output-dir-mirror")) { NEXT_FIELD(outMirroredDirName); continue; }
#endif
Expand Down Expand Up @@ -1156,8 +1169,13 @@ int main(int const argCount, const char* argv[])
#ifdef ZSTD_MULTITHREAD
if ((nbWorkers==0) && (!singleThread)) {
/* automatically set # workers based on # of reported cpus */
nbWorkers = UTIL_countPhysicalCores();
DISPLAYLEVEL(3, "Note: %d physical core(s) detected \n", nbWorkers);
if (defaultLogicalCores) {
nbWorkers = UTIL_countLogicalCores();
DISPLAYLEVEL(3, "Note: %d logical core(s) detected \n", nbWorkers);
} else {
nbWorkers = UTIL_countPhysicalCores();
DISPLAYLEVEL(3, "Note: %d physical core(s) detected \n", nbWorkers);
}
}
#else
(void)singleThread; (void)nbWorkers;
Expand Down
2 changes: 2 additions & 0 deletions tests/playTests.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -1351,6 +1351,8 @@ if [ -n "$hasMT" ]
then
println "\n===> zstdmt round-trip tests "
roundTripTest -g4M "1 -T0"
roundTripTest -g4M "1 -T0 --auto-threads=physical"
roundTripTest -g4M "1 -T0 --auto-threads=logical"
roundTripTest -g8M "3 -T2"
roundTripTest -g8M "19 --long"
roundTripTest -g8000K "2 --threads=2"
Expand Down

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