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authorRickard Green <[email protected]>2010-08-16 19:38:33 +0200
committerRickard Green <[email protected]>2010-08-18 18:00:34 +0200
commit1b273b618002d65159453fdfb9520a9476e4423a (patch)
tree1bb787ea400e726e575237274e347bd928787e84
parentbdfd2aaa1d402b3dd393a7820432f8f76e248ee1 (diff)
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Make it possible to reread and update detected CPU information
Calling erlang:system_info/1 with the new argument 'update_cpu_info' will make the runtime system reread and update the internally stored CPU information. For more information see the documentation of erlang:system_info(update_cpu_info).
-rw-r--r--erts/doc/src/erlang.xml55
-rw-r--r--erts/emulator/beam/erl_bif_info.c24
-rw-r--r--erts/emulator/beam/erl_process.c35
-rw-r--r--erts/emulator/beam/erl_process.h1
-rw-r--r--erts/include/internal/erl_misc_utils.h4
-rw-r--r--erts/lib_src/common/erl_misc_utils.c212
6 files changed, 258 insertions, 73 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 54a0a80536..cb3112acfe 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -5533,7 +5533,7 @@ true</pre>
<c>CpuTopology</c> type to change.
</p>
</item>
- <tag><c>{cpu_topology, defined}</c></tag>
+ <tag><marker id="system_info_cpu_topology_defined"><c>{cpu_topology, defined}</c></marker></tag>
<item>
<p>Returns the user defined <c>CpuTopology</c>. For more
information see the documentation of
@@ -5543,7 +5543,7 @@ true</pre>
argument.
</p>
</item>
- <tag><c>{cpu_topology, detected}</c></tag>
+ <tag><marker id="system_info_cpu_topology_detected"><c>{cpu_topology, detected}</c></marker></tag>
<item>
<p>Returns the automatically detected <c>CpuTopology</c>. The
emulator currently only detects the CPU topology on some newer
@@ -5727,11 +5727,34 @@ true</pre>
information see the <seealso marker="erts:crash_dump">"How to interpret the Erlang crash dumps"</seealso> chapter
in the ERTS User's Guide.</p>
</item>
- <tag><c>logical_processors</c></tag>
+ <tag><marker id="logical_processors"><c>logical_processors</c></marker></tag>
<item>
- <p>Returns the number of logical processors detected on the
- system as an integer or the atom <c>unknown</c> if the
- emulator wasn't able to detect any.
+ <p>Returns the detected number of logical processors configured
+ on the system. The return value is either an integer, or
+ the atom <c>unknown</c> if the emulator wasn't able to
+ detect logical processors configured.
+ </p>
+ </item>
+ <tag><marker id="logical_processors_available"><c>logical_processors_available</c></marker></tag>
+ <item>
+ <p>Returns the detected number of logical processors available to
+ the Erlang runtime system. The return value is either an
+ integer, or the atom <c>unknown</c> if the emulator wasn't
+ able to detect logical processors available. The number
+ of logical processors available is less than or equal to
+ the number of <seealso marker="#logical_processors_online">logical
+ processors online</seealso>.
+ </p>
+ </item>
+ <tag><marker id="logical_processors_online"><c>logical_processors_online</c></marker></tag>
+ <item>
+ <p>Returns the detected number of logical processors online on
+ the system. The return value is either an integer,
+ or the atom <c>unknown</c> if the emulator wasn't able to
+ detect logical processors online. The number of logical
+ processors online is less than or equal to the number of
+ <seealso marker="#logical_processors">logical processors
+ configured</seealso>.
</p>
</item>
<tag><c>machine</c></tag>
@@ -5936,6 +5959,26 @@ true</pre>
<c>get_tcw</c> in "Match Specifications in Erlang",
<seealso marker="erts:match_spec#get_tcw">ERTS User's Guide</seealso>.</p>
</item>
+ <tag><marker id="update_cpu_info"><c>update_cpu_info</c></marker></tag>
+ <item>
+ <p>The runtime system rereads the CPU information available and
+ updates its internally stored information about the
+ <seealso marker="#system_info_cpu_topology_detected">detected CPU
+ topology</seealso> and the amount of logical processors
+ <seealso marker="#logical_processors">configured</seealso>,
+ <seealso marker="#logical_processors_online">online</seealso>, and
+ <seealso marker="#logical_processors_available">available</seealso>.
+ If the CPU information has changed since the last time it was read,
+ the atom <c>changed</c> is returned; otherwise, the atom
+ <c>unchanged</c> is returned. If the CPU information has changed
+ you probably want to
+ <seealso marker="#system_flag_schedulers_online">adjust the amount
+ of schedulers online</seealso>. You typically want to have as
+ many schedulers online as
+ <seealso marker="#logical_processors_available">logical processors
+ available</seealso>.
+ </p>
+ </item>
<tag><marker id="system_info_version"><c>version</c></marker></tag>
<item>
<p>Returns a string containing the version number of the
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 5128776c47..d5ae3d2174 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2316,6 +2316,15 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
} else if (ERTS_IS_ATOM_STR("cpu_topology", BIF_ARG_1)) {
res = erts_get_cpu_topology_term(BIF_P, am_used);
BIF_TRAP1(erts_format_cpu_topology_trap, BIF_P, res);
+ } else if (ERTS_IS_ATOM_STR("update_cpu_info", BIF_ARG_1)) {
+ if (erts_update_cpu_info()) {
+ ERTS_DECL_AM(changed);
+ BIF_RET(AM_changed);
+ }
+ else {
+ ERTS_DECL_AM(unchanged);
+ BIF_RET(AM_unchanged);
+ }
#if defined(__GNUC__) && defined(HAVE_SOLARIS_SPARC_PERFMON)
} else if (ERTS_IS_ATOM_STR("ultrasparc_read_tick1", BIF_ARG_1)) {
register unsigned high asm("%l0");
@@ -2387,7 +2396,10 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
}
/* Arguments that are unusual follow ... */
else if (ERTS_IS_ATOM_STR("logical_processors", BIF_ARG_1)) {
- int no = erts_get_cpu_configured(erts_cpuinfo);
+ int no;
+ erts_smp_rwmtx_rlock(&erts_cpu_bind_rwmtx);
+ no = erts_get_cpu_configured(erts_cpuinfo);
+ erts_smp_rwmtx_runlock(&erts_cpu_bind_rwmtx);
if (no > 0)
BIF_RET(make_small((Uint) no));
else {
@@ -2396,7 +2408,10 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
}
}
else if (ERTS_IS_ATOM_STR("logical_processors_online", BIF_ARG_1)) {
- int no = erts_get_cpu_online(erts_cpuinfo);
+ int no;
+ erts_smp_rwmtx_rlock(&erts_cpu_bind_rwmtx);
+ no = erts_get_cpu_online(erts_cpuinfo);
+ erts_smp_rwmtx_runlock(&erts_cpu_bind_rwmtx);
if (no > 0)
BIF_RET(make_small((Uint) no));
else {
@@ -2405,7 +2420,10 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
}
}
else if (ERTS_IS_ATOM_STR("logical_processors_available", BIF_ARG_1)) {
- int no = erts_get_cpu_available(erts_cpuinfo);
+ int no;
+ erts_smp_rwmtx_rlock(&erts_cpu_bind_rwmtx);
+ no = erts_get_cpu_available(erts_cpuinfo);
+ erts_smp_rwmtx_runlock(&erts_cpu_bind_rwmtx);
if (no > 0)
BIF_RET(make_small((Uint) no));
else {
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index a644520442..457e283034 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -3962,7 +3962,7 @@ check_cpu_bind(ErtsSchedulerData *esdp)
goto unbind;
}
}
- else if (cpu_id < 0 && scheduler2cpu_map[esdp->no].bound_id >= 0) {
+ else if (cpu_id < 0) /* && scheduler2cpu_map[esdp->no].bound_id >= 0) */ {
unbind:
/* Get rid of old binding */
res = erts_unbind_from_cpu(erts_cpuinfo);
@@ -5521,6 +5521,39 @@ late_cpu_bind_init(void)
}
}
+int
+erts_update_cpu_info(void)
+{
+ int changed;
+ erts_smp_rwmtx_rwlock(&erts_cpu_bind_rwmtx);
+ changed = erts_cpu_info_update(erts_cpuinfo);
+ if (changed) {
+ erts_cpu_topology_t *cpudata;
+ int cpudata_size;
+ erts_free(ERTS_ALC_T_CPUDATA, system_cpudata);
+
+ system_cpudata_size = erts_get_cpu_topology_size(erts_cpuinfo);
+ system_cpudata = erts_alloc(ERTS_ALC_T_CPUDATA,
+ (sizeof(erts_cpu_topology_t)
+ * system_cpudata_size));
+
+ if (!erts_get_cpu_topology(erts_cpuinfo, system_cpudata)
+ || ERTS_INIT_CPU_TOPOLOGY_OK != verify_topology(system_cpudata,
+ system_cpudata_size)) {
+ erts_free(ERTS_ALC_T_CPUDATA, system_cpudata);
+ system_cpudata = NULL;
+ system_cpudata_size = 0;
+ }
+
+ create_tmp_cpu_topology_copy(&cpudata, &cpudata_size);
+ ASSERT(cpudata);
+ signal_schedulers_bind_change(cpudata, cpudata_size);
+ destroy_tmp_cpu_topology_copy(cpudata);
+ }
+ erts_smp_rwmtx_rwunlock(&erts_cpu_bind_rwmtx);
+ return changed;
+}
+
#ifdef ERTS_SMP
static void
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index c3fef6d38e..0cc4a715ad 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -1025,6 +1025,7 @@ int erts_init_scheduler_bind_type(char *how);
#define ERTS_INIT_CPU_TOPOLOGY_MISSING 9
int erts_init_cpu_topology(char *topology_str);
+int erts_update_cpu_info(void);
void erts_pre_init_process(void);
void erts_late_init_process(void);
diff --git a/erts/include/internal/erl_misc_utils.h b/erts/include/internal/erl_misc_utils.h
index 6b875ff824..dda2cab5c6 100644
--- a/erts/include/internal/erl_misc_utils.h
+++ b/erts/include/internal/erl_misc_utils.h
@@ -1,7 +1,7 @@
/*
* %CopyrightBegin%
*
- * Copyright Ericsson AB 2006-2009. All Rights Reserved.
+ * Copyright Ericsson AB 2006-2010. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
@@ -34,7 +34,7 @@ typedef struct {
erts_cpu_info_t *erts_cpu_info_create(void);
void erts_cpu_info_destroy(erts_cpu_info_t *cpuinfo);
-void erts_cpu_info_update(erts_cpu_info_t *cpuinfo);
+int erts_cpu_info_update(erts_cpu_info_t *cpuinfo);
int erts_get_cpu_configured(erts_cpu_info_t *cpuinfo);
int erts_get_cpu_online(erts_cpu_info_t *cpuinfo);
int erts_get_cpu_available(erts_cpu_info_t *cpuinfo);
diff --git a/erts/lib_src/common/erl_misc_utils.c b/erts/lib_src/common/erl_misc_utils.c
index d2ef7140a5..6346fe361d 100644
--- a/erts/lib_src/common/erl_misc_utils.c
+++ b/erts/lib_src/common/erl_misc_utils.c
@@ -62,10 +62,10 @@
#if defined(HAVE_SCHED_xETAFFINITY)
# include <sched.h>
# define ERTS_HAVE_MISC_UTIL_AFFINITY_MASK__
-#define ERTS_MU_GET_PROC_AFFINITY__(CPUINFOP) \
+#define ERTS_MU_GET_PROC_AFFINITY__(CPUINFOP, CPUSET) \
(sched_getaffinity((CPUINFOP)->pid, \
sizeof(cpu_set_t), \
- &(CPUINFOP)->cpuset) != 0 ? -errno : 0)
+ (CPUSET)) != 0 ? -errno : 0)
#define ERTS_MU_SET_THR_AFFINITY__(SETP) \
(sched_setaffinity(0, sizeof(cpu_set_t), (SETP)) != 0 ? -errno : 0)
#elif defined(__WIN32__)
@@ -99,6 +99,26 @@
static int read_topology(erts_cpu_info_t *cpuinfo);
+#if defined(ERTS_HAVE_MISC_UTIL_AFFINITY_MASK__)
+static int
+cpu_sets_are_eq(cpu_set_t *x, cpu_set_t *y)
+{
+ int i;
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (CPU_ISSET(i, x)) {
+ if (!CPU_ISSET(i, y))
+ return 0;
+ }
+ else {
+ if (CPU_ISSET(i, y))
+ return 0;
+ }
+ }
+ return 1;
+}
+
+#endif
+
int
erts_milli_sleep(long ms)
{
@@ -137,15 +157,15 @@ struct erts_cpu_info_t_ {
#if defined(__WIN32__)
static __forceinline int
-get_proc_affinity(erts_cpu_info_t *cpuinfo)
+get_proc_affinity(erts_cpu_info_t *cpuinfo, cpu_set_t *cpuset)
{
DWORD pamask, samask;
if (GetProcessAffinityMask(GetCurrentProcess(), &pamask, &samask)) {
- cpuinfo->cpuset = (cpu_set_t) pamask;
+ *cpuset = (cpu_set_t) pamask;
return 0;
}
else {
- cpuinfo->cpuset = (cpu_set_t) 0;
+ *cpuset = (cpu_set_t) 0;
return -erts_get_last_win_errno();
}
}
@@ -179,6 +199,9 @@ erts_cpu_info_create(void)
#endif
cpuinfo->topology_size = 0;
cpuinfo->topology = NULL;
+ cpuinfo->configured = -1;
+ cpuinfo->online = -1;
+ cpuinfo->available = -1;
erts_cpu_info_update(cpuinfo);
return cpuinfo;
}
@@ -203,34 +226,40 @@ erts_cpu_info_destroy(erts_cpu_info_t *cpuinfo)
}
}
-void
+int
erts_cpu_info_update(erts_cpu_info_t *cpuinfo)
{
- cpuinfo->configured = 0;
- cpuinfo->online = 0;
- cpuinfo->available = 0;
+ int changed = 0;
+ int configured = 0;
+ int online = 0;
+ int available = 0;
+ erts_cpu_topology_t *old_topology;
+ int old_topology_size;
+#if defined(ERTS_HAVE_MISC_UTIL_AFFINITY_MASK__)
+ cpu_set_t cpuset;
+#endif
#ifdef __WIN32__
{
int i;
SYSTEM_INFO sys_info;
GetSystemInfo(&sys_info);
- cpuinfo->configured = (int) sys_info.dwNumberOfProcessors;
+ configured = (int) sys_info.dwNumberOfProcessors;
for (i = 0; i < sizeof(DWORD)*8; i++)
if (sys_info.dwActiveProcessorMask & (((DWORD) 1) << i))
- cpuinfo->online++;
+ online++;
}
#elif !defined(NO_SYSCONF) && (defined(_SC_NPROCESSORS_CONF) \
|| defined(_SC_NPROCESSORS_ONLN))
#ifdef _SC_NPROCESSORS_CONF
- cpuinfo->configured = (int) sysconf(_SC_NPROCESSORS_CONF);
- if (cpuinfo->configured < 0)
- cpuinfo->configured = 0;
+ configured = (int) sysconf(_SC_NPROCESSORS_CONF);
+ if (configured < 0)
+ configured = 0;
#endif
#ifdef _SC_NPROCESSORS_ONLN
- cpuinfo->online = (int) sysconf(_SC_NPROCESSORS_ONLN);
- if (cpuinfo->online < 0)
- cpuinfo->online = 0;
+ online = (int) sysconf(_SC_NPROCESSORS_ONLN);
+ if (online < 0)
+ online = 0;
#endif
#elif defined(HAVE_SYS_SYSCTL_H) && defined(CTL_HW) && (defined(HW_NCPU) \
|| defined(HW_AVAILCPU))
@@ -242,71 +271,138 @@ erts_cpu_info_update(erts_cpu_info_t *cpuinfo)
len = sizeof(int);
mib[0] = CTL_HW;
mib[1] = HW_NCPU;
- if (sysctl(&mib[0], 2, &cpuinfo->configured, &len, NULL, 0) < 0)
- cpuinfo->configured = 0;
+ if (sysctl(&mib[0], 2, &configured, &len, NULL, 0) < 0)
+ configured = 0;
#endif
#ifdef HW_AVAILCPU
len = sizeof(int);
mib[0] = CTL_HW;
mib[1] = HW_AVAILCPU;
- if (sysctl(&mib[0], 2, &cpuinfo->online, &len, NULL, 0) < 0)
- cpuinfo->online = 0;
+ if (sysctl(&mib[0], 2, &online, &len, NULL, 0) < 0)
+ online = 0;
#endif
}
#endif
- if (cpuinfo->online > cpuinfo->configured)
- cpuinfo->online = cpuinfo->configured;
+ if (online > configured)
+ online = configured;
+
+ if (cpuinfo->configured != configured)
+ changed = 1;
+ if (cpuinfo->online != online)
+ changed = 1;
#if defined(ERTS_HAVE_MISC_UTIL_AFFINITY_MASK__)
- if (ERTS_MU_GET_PROC_AFFINITY__(cpuinfo) == 0) {
- int i, c, cn, si;
- c = cn = 0;
- si = sizeof(cpuinfo->affinity_str_buf) - 1;
- cpuinfo->affinity_str_buf[si] = '\0';
- for (i = 0; i < CPU_SETSIZE; i++) {
- if (CPU_ISSET(i, &cpuinfo->cpuset)) {
- c |= 1 << cn;
- cpuinfo->available++;
+ if (ERTS_MU_GET_PROC_AFFINITY__(cpuinfo, &cpuset) == 0) {
+ if (!changed && !cpu_sets_are_eq(&cpuset, &cpuinfo->cpuset))
+ changed = 1;
+
+ if (!changed)
+ available = cpuinfo->available;
+ else {
+ int i, c, cn, si;
+
+ memcpy((void *) &cpuinfo->cpuset,
+ (void *) &cpuset,
+ sizeof(cpu_set_t));
+
+ c = cn = 0;
+ si = sizeof(cpuinfo->affinity_str_buf) - 1;
+ cpuinfo->affinity_str_buf[si] = '\0';
+ for (i = 0; i < CPU_SETSIZE; i++) {
+ if (CPU_ISSET(i, &cpuinfo->cpuset)) {
+ c |= 1 << cn;
+ available++;
+ }
+ cn++;
+ if (cn == 4) {
+ cpuinfo->affinity_str_buf[--si] = (c < 10
+ ? '0' + c
+ : 'A' + c - 10);
+ c = cn = 0;
+ }
}
- cn++;
- if (cn == 4) {
+ if (c)
cpuinfo->affinity_str_buf[--si] = (c < 10
? '0' + c
: 'A' + c - 10);
- c = cn = 0;
- }
+ while (cpuinfo->affinity_str_buf[si] == '0')
+ si++;
+ cpuinfo->affinity_str = &cpuinfo->affinity_str_buf[si];
}
- if (c)
- cpuinfo->affinity_str_buf[--si] = (c < 10
- ? '0' + c
- : 'A' + c - 10);
- while (cpuinfo->affinity_str_buf[si] == '0')
- si++;
- cpuinfo->affinity_str = &cpuinfo->affinity_str_buf[si];
}
#elif defined(HAVE_PSET_INFO)
{
- uint_t numcpus = cpuinfo->configured;
- if (cpuinfo->cpuids)
- free(cpuinfo->cpuids);
- cpuinfo->cpuids = malloc(sizeof(processorid_t)*numcpus);
- if (cpuinfo->cpuids) {
- if (pset_info(PS_MYID, NULL, &numcpus, &cpuinfo->cpuids) == 0)
- cpuinfo->available = (int) numcpus;
- if (cpuinfo->available < 0) {
- free(cpuinfo->cpuid);
- cpuinfo->available = 0;
+ processorid_t *cpuids;
+ uint_t numcpus = configured;
+ cpuids = malloc(sizeof(processorid_t)*numcpus);
+ if (cpuids) {
+ if (pset_info(PS_MYID, NULL, &numcpus, &cpuids) == 0)
+ available = (int) numcpus;
+ if (available < 0) {
+ free(cpuids);
+ cpuids = NULL;
+ available = 0;
}
}
+ if (!cpuids) {
+ if (cpuinfo->cpuids)
+ changed = 1;
+ }
+ else {
+ if (cpuinfo->cpuids)
+ changed = 1;
+ if (memcmp((void *) cpuinfo->cpuids,
+ (void *) cpuids,
+ sizeof(processorid_t)*numcpus) != 0)
+ changed = 1;
+
+ }
+ if (!changed) {
+ if (cpuids)
+ free(cpuids);
+ }
+ else {
+ if (cpuinfo->cpuids)
+ free(cpuinfo->cpuids);
+ cpuinfo->cpuids = cpuids;
+ }
}
#endif
- if (cpuinfo->available > cpuinfo->online)
- cpuinfo->available = cpuinfo->online;
+ if (available > online)
+ available = online;
+
+ if (cpuinfo->available != available)
+ changed = 1;
+
+ cpuinfo->configured = configured;
+ cpuinfo->online = online;
+ cpuinfo->available = available;
+
+ old_topology = cpuinfo->topology;
+ old_topology_size = cpuinfo->topology_size;
+ cpuinfo->topology = NULL;
read_topology(cpuinfo);
+ if (cpuinfo->topology_size != old_topology_size
+ || (old_topology_size != 0
+ && memcmp((void *) cpuinfo->topology,
+ (void *) old_topology,
+ (sizeof(erts_cpu_topology_t)
+ * old_topology_size)) != 0)) {
+ changed = 1;
+ if (old_topology)
+ free(old_topology);
+ }
+ else {
+ if (cpuinfo->topology)
+ free(cpuinfo->topology);
+ cpuinfo->topology = old_topology;
+ }
+
+ return changed;
}
int
@@ -641,9 +737,6 @@ read_topology(erts_cpu_info_t *cpuinfo)
errno = 0;
- if (cpuinfo->topology)
- free(cpuinfo->topology);
-
if (cpuinfo->configured < 1)
goto error;
@@ -896,9 +989,6 @@ read_topology(erts_cpu_info_t *cpuinfo)
errno = 0;
- if (cpuinfo->topology)
- free(cpuinfo->topology);
-
if (cpuinfo->configured < 1)
goto error;