diff options
| author | Heiko Carstens | 2014-03-10 14:50:16 +0100 |
|---|---|---|
| committer | Martin Schwidefsky | 2014-03-17 15:53:06 +0100 |
| commit | cf813db0b448b45b454f0983329c3c7b007f9ab7 (patch) | |
| tree | 2ccbddbc0c1494d92e4fa4f1c2f7d337595e1dd2 /arch/s390 | |
| parent | 36a554021b44d146178ae98e598c9502a1269f7d (diff) | |
s390/smp: limit number of cpus in possible cpu mask
Limit the number of bits to the maximum number of cpus a machine
can have.
possible_cpu_mask typically will have more bits set than a machine
may physically have. This results in wasted memory during per-cpu
memory allocations, if the possible mask contains more cpus than
physically possible for a given configuration.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/sclp.h | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/smp.c | 8 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h index abaca2275c7a..2f5e9932b4de 100644 --- a/arch/s390/include/asm/sclp.h +++ b/arch/s390/include/asm/sclp.h @@ -46,6 +46,7 @@ int sclp_cpu_configure(u8 cpu); int sclp_cpu_deconfigure(u8 cpu); unsigned long long sclp_get_rnmax(void); unsigned long long sclp_get_rzm(void); +unsigned int sclp_get_max_cpu(void); int sclp_sdias_blk_count(void); int sclp_sdias_copy(void *dest, int blk_num, int nr_blks); int sclp_chp_configure(struct chp_id chpid); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index a7125b62a9a6..8827883310dd 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -773,11 +773,11 @@ void __noreturn cpu_die(void) void __init smp_fill_possible_mask(void) { - unsigned int possible, cpu; + unsigned int possible, sclp, cpu; - possible = setup_possible_cpus; - if (!possible) - possible = MACHINE_IS_VM ? 64 : nr_cpu_ids; + sclp = sclp_get_max_cpu() ?: nr_cpu_ids; + possible = setup_possible_cpus ?: nr_cpu_ids; + possible = min(possible, sclp); for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) set_cpu_possible(cpu, true); } |