On Tue, Oct 23, 2012 at 01:49:46PM -0600, Toshi Kani wrote:
> 1) The system has 4 CPUs
> $ lscpu -a -e
> CPU NODE SOCKET CORE L1d:L1i:L2 ONLINE
> 0 0 0 0 0:0:0 yes
> 1 0 1 1 1:1:1 yes
> 2 0 2 2 2:2:2 yes
> 3 0 3 3 3:3:3 yes
>
> 2) Eject cpu2
> # echo 1 > /sys/bus/acpi/devices/LNXCPU:02/eject
>
> 3) lscpu no longer recognizes cpu3 after cpu2 is ejected
> $ lscpu -a -e
> CPU NODE SOCKET CORE L1d:L1i:L2 ONLINE
> 0 0 0 0 0:0:0 yes
> 1 0 1 1 1:1:1 yes
>
> The following changes are made to address this issue.
> - Use maxcpus to allocate and parse bitmaps.
> - Set desc->ncpu from cpu/present, which includes both on-line
> and off-line CPUs.
In the directory tests we have a dump from some strange machine
tests/ts/lscpu/dumps/sparc64-UltraSparc-T1.tar.gz
where is 32 /sys/devices/system/cpu/cpu[0-9]* subdirectories, but the
present mask is 0-23, all the masks from the dump:
present: 0-23
possible: 0-31
online: 0-23
offline: 24-31
count: 32 (means ls -d sys/devices/system/cpu/cpu[0-9]* | wc -l)
strange, right? But I guess we can ignore this dump, according to
kernel Documentation/cpu-hotplug.txt the cpu[0-9]* subdirectories
have to follow the present mask. Maybe the dump is broken or so..
Note that many of our old dumps in the tests/ts/lscpu/dumps don't
contain /sys/devices/system/cpu/{present,online,possible} masks, but
I will drop these incomplete dumps.
> - desc->coremaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
> - desc->socketmaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
> + desc->coremaps = xcalloc(maxcpus, sizeof(cpu_set_t *));
> + desc->socketmaps = xcalloc(maxcpus, sizeof(cpu_set_t *));
[...]
> - for (i = 0; i < desc->ncpus; i++) {
> + for (i = 0; i < maxcpus; i++) {
> read_topology(desc, i);
> read_cache(desc, i);
> read_polarization(desc, i);
What about to read /sys/devices/system/cpu/possible to determine the
maximal possible number of CPUs on the machine. It seems like
overkill to follow the maximal size of the cpu_set_t mask (=maxcpus).
The "possible" mask is static and no affected by hot-plug.
See the patch below.
Karel
diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 25a0273..5b1a0af 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -150,7 +150,9 @@ struct lscpu_desc {
int dispatching; /* none, horizontal or vertical */
int mode; /* rm, lm or/and tm */
- int ncpus; /* number of CPUs */
+ int ncpuspos; /* maximal possible CPUs */
+ int ncpus; /* number of present CPUs */
+ cpu_set_t *present; /* mask with present CPUs */
cpu_set_t *online; /* mask with online CPUs */
int nnodes; /* number of NUMA modes */
@@ -204,8 +206,11 @@ struct lscpu_modifier {
static int maxcpus; /* size in bits of kernel cpu mask */
#define is_cpu_online(_d, _cpu) \
- ((_d) && (_d)->online ? \
- CPU_ISSET_S((_cpu), CPU_ALLOC_SIZE(maxcpus), (_d)->online) : 0)
+ ((_d) && (_d)->online ? \
+ CPU_ISSET_S((_cpu), CPU_ALLOC_SIZE(maxcpus), (_d)->online) : 0)
+#define is_cpu_present(_d, _cpu) \
+ ((_d) && (_d)->present ? \
+ CPU_ISSET_S((_cpu), CPU_ALLOC_SIZE(maxcpus), (_d)->present) : 0)
/*
* IDs
@@ -334,16 +339,13 @@ read_basicinfo(struct lscpu_desc *desc, struct lscpu_modifier *mod)
FILE *fp = path_fopen("r", 1, _PATH_PROC_CPUINFO);
char buf[BUFSIZ];
struct utsname utsbuf;
+ size_t setsize;
/* architecture */
if (uname(&utsbuf) == -1)
err(EXIT_FAILURE, _("error: uname failed"));
desc->arch = xstrdup(utsbuf.machine);
- /* count CPU(s) */
- while(path_exist(_PATH_SYS_SYSTEM "/cpu/cpu%d", desc->ncpus))
- desc->ncpus++;
-
/* details */
while (fgets(buf, sizeof(buf), fp) != NULL) {
if (lookup(buf, "vendor", &desc->vendor)) ;
@@ -391,11 +393,27 @@ read_basicinfo(struct lscpu_desc *desc, struct lscpu_modifier *mod)
if (maxcpus <= 0)
/* error or we are reading some /sys snapshot instead of the
* real /sys, let's use any crazy number... */
- maxcpus = desc->ncpus > 2048 ? desc->ncpus : 2048;
+ maxcpus = 2048;
+
+ setsize = CPU_ALLOC_SIZE(maxcpus);
+
+ if (path_exist(_PATH_SYS_SYSTEM "/cpu/possible")) {
+ cpu_set_t *tmp = path_cpulist(maxcpus, _PATH_SYS_SYSTEM "/cpu/possible");
+ desc->ncpuspos = CPU_COUNT_S(setsize, tmp);
+ cpuset_free(tmp);
+ } else
+ err(EXIT_FAILURE, _("failed to determine number of CPUs: %s"),
+ _PATH_SYS_SYSTEM "/cpu/possible");
+
+
+ /* get mask for present CPUs */
+ if (path_exist(_PATH_SYS_SYSTEM "/cpu/present")) {
+ desc->present = path_cpulist(maxcpus, _PATH_SYS_SYSTEM "/cpu/present");
+ desc->ncpus = CPU_COUNT_S(setsize, desc->present);
+ }
/* get mask for online CPUs */
if (path_exist(_PATH_SYS_SYSTEM "/cpu/online")) {
- size_t setsize = CPU_ALLOC_SIZE(maxcpus);
desc->online = path_cpulist(maxcpus, _PATH_SYS_SYSTEM "/cpu/online");
desc->nthreads = CPU_COUNT_S(setsize, desc->online);
}
@@ -626,16 +644,16 @@ read_topology(struct lscpu_desc *desc, int num)
*/
if (!desc->nthreads)
desc->nthreads = nbooks * nsockets * ncores * nthreads;
- /* For each map we make sure that it can have up to ncpus
+ /* For each map we make sure that it can have up to ncpuspos
* entries. This is because we cannot reliably calculate the
* number of cores, sockets and books on all architectures.
* E.g. completely virtualized architectures like s390 may
* have multiple sockets of different sizes.
*/
- desc->coremaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
- desc->socketmaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
+ desc->coremaps = xcalloc(desc->ncpuspos, sizeof(cpu_set_t *));
+ desc->socketmaps = xcalloc(desc->ncpuspos, sizeof(cpu_set_t *));
if (book_siblings)
- desc->bookmaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
+ desc->bookmaps = xcalloc(desc->ncpuspos, sizeof(cpu_set_t *));
}
add_cpuset_to_array(desc->socketmaps, &desc->nsockets, core_siblings);
@@ -653,7 +671,7 @@ read_polarization(struct lscpu_desc *desc, int num)
if (!path_exist(_PATH_SYS_CPU "/cpu%d/polarization", num))
return;
if (!desc->polarization)
- desc->polarization = xcalloc(desc->ncpus, sizeof(int));
+ desc->polarization = xcalloc(desc->ncpuspos, sizeof(int));
path_getstr(mode, sizeof(mode), _PATH_SYS_CPU "/cpu%d/polarization", num);
if (strncmp(mode, "vertical:low", sizeof(mode)) == 0)
desc->polarization[num] = POLAR_VLOW;
@@ -673,7 +691,7 @@ read_address(struct lscpu_desc *desc, int num)
if (!path_exist(_PATH_SYS_CPU "/cpu%d/address", num))
return;
if (!desc->addresses)
- desc->addresses = xcalloc(desc->ncpus, sizeof(int));
+ desc->addresses = xcalloc(desc->ncpuspos, sizeof(int));
desc->addresses[num] = path_getnum(_PATH_SYS_CPU "/cpu%d/address", num);
}
@@ -683,7 +701,7 @@ read_configured(struct lscpu_desc *desc, int num)
if (!path_exist(_PATH_SYS_CPU "/cpu%d/configure", num))
return;
if (!desc->configured)
- desc->configured = xcalloc(desc->ncpus, sizeof(int));
+ desc->configured = xcalloc(desc->ncpuspos, sizeof(int));
desc->configured[num] = path_getnum(_PATH_SYS_CPU "/cpu%d/configure", num);
}
@@ -756,7 +774,7 @@ read_cache(struct lscpu_desc *desc, int num)
num, i);
if (!ca->sharedmaps)
- ca->sharedmaps = xcalloc(desc->ncpus, sizeof(cpu_set_t *));
+ ca->sharedmaps = xcalloc(desc->ncpuspos, sizeof(cpu_set_t *));
add_cpuset_to_array(ca->sharedmaps, &ca->nsharedmaps, map);
}
}
@@ -982,13 +1000,15 @@ print_parsable(struct lscpu_desc *desc, int cols[], int ncols,
/*
* Data
*/
- for (i = 0; i < desc->ncpus; i++) {
+ for (i = 0; i < desc->ncpuspos; i++) {
int c;
if (!mod->offline && desc->online && !is_cpu_online(desc, i))
continue;
if (!mod->online && desc->online && is_cpu_online(desc, i))
continue;
+ if (desc->present && !is_cpu_present(desc, i))
+ continue;
for (c = 0; c < ncols; c++) {
if (mod->compat && cols[c] == COL_CACHE) {
if (!desc->ncaches)
@@ -1026,7 +1046,7 @@ print_readable(struct lscpu_desc *desc, int cols[], int ncols,
tt_define_column(tt, xstrdup(data), 0, 0);
}
- for (i = 0; i < desc->ncpus; i++) {
+ for (i = 0; i < desc->ncpuspos; i++) {
int c;
struct tt_line *line;
@@ -1034,6 +1054,8 @@ print_readable(struct lscpu_desc *desc, int cols[], int ncols,
continue;
if (!mod->online && desc->online && is_cpu_online(desc, i))
continue;
+ if (desc->present && !is_cpu_present(desc, i))
+ continue;
line = tt_add_line(tt, NULL);
@@ -1117,8 +1139,8 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
if (!set)
err(EXIT_FAILURE, _("failed to callocate cpu set"));
CPU_ZERO_S(setsize, set);
- for (i = 0; i < desc->ncpus; i++) {
- if (!is_cpu_online(desc, i))
+ for (i = 0; i < desc->ncpuspos; i++) {
+ if (!is_cpu_online(desc, i) && is_cpu_present(desc, i))
CPU_SET_S(i, setsize, set);
}
print_cpuset(mod->hex ? _("Off-line CPU(s) mask:") :
@@ -1339,7 +1361,7 @@ int main(int argc, char *argv[])
read_basicinfo(desc, mod);
- for (i = 0; i < desc->ncpus; i++) {
+ for (i = 0; i < desc->ncpuspos; i++) {
read_topology(desc, i);
read_cache(desc, i);
read_polarization(desc, i);
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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