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s390/smp: reduce size of struct pcpu 

Reduce the size of struct pcpu, since the pcpu_devices array consists
of NR_CPUS elements of type struct pcpu. For most machines this is just
a waste of memory.
So let's try to make it a bit smaller.
This saves 16k with performance_defconfig.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2015-02-11 12:31:03 +01:00 committed by Martin Schwidefsky
parent da0c636ea7
commit 2f859d0dad
1 changed files with 27 additions and 27 deletions
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54
arch/s390/kernel/smp.c
View File

@ -59,14 +59,13 @@ enum {
CPU_STATE_CONFIGURED,
};
static DEFINE_PER_CPU(struct cpu *, cpu_device);
struct pcpu {
struct cpu *cpu;
struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
unsigned long async_stack; /* async stack for the cpu */
unsigned long panic_stack; /* panic stack for the cpu */
unsigned long ec_mask; /* bit mask for ec_xxx functions */
int state; /* physical cpu state */
int polarization; /* physical polarization */
signed char state; /* physical cpu state */
signed char polarization; /* physical polarization */
u16 address; /* physical cpu address */
};
@ -173,25 +172,30 @@ static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
pcpu_sigp_retry(pcpu, order, 0);
}
#define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
#define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE)
static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
{
unsigned long async_stack, panic_stack;
struct _lowcore *lc;
if (pcpu != &pcpu_devices[0]) {
pcpu->lowcore = (struct _lowcore *)
__get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
pcpu->panic_stack = __get_free_page(GFP_KERNEL);
if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
panic_stack = __get_free_page(GFP_KERNEL);
if (!pcpu->lowcore || !panic_stack || !async_stack)
goto out;
} else {
async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET;
panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET;
}
lc = pcpu->lowcore;
memcpy(lc, &S390_lowcore, 512);
memset((char *) lc + 512, 0, sizeof(*lc) - 512);
lc->async_stack = pcpu->async_stack + ASYNC_SIZE
- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
lc->async_stack = async_stack + ASYNC_FRAME_OFFSET;
lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET;
lc->cpu_nr = cpu;
lc->spinlock_lockval = arch_spin_lockval(cpu);
#ifndef CONFIG_64BIT
@ -212,8 +216,8 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
return 0;
out:
if (pcpu != &pcpu_devices[0]) {
free_page(pcpu->panic_stack);
free_pages(pcpu->async_stack, ASYNC_ORDER);
free_page(panic_stack);
free_pages(async_stack, ASYNC_ORDER);
free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
}
return -ENOMEM;
@ -235,11 +239,11 @@ static void pcpu_free_lowcore(struct pcpu *pcpu)
#else
vdso_free_per_cpu(pcpu->lowcore);
#endif
if (pcpu != &pcpu_devices[0]) {
free_page(pcpu->panic_stack);
free_pages(pcpu->async_stack, ASYNC_ORDER);
free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
}
if (pcpu == &pcpu_devices[0])
return;
free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET);
free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER);
free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
}
#endif /* CONFIG_HOTPLUG_CPU */
@ -366,7 +370,8 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
void smp_call_ipl_cpu(void (*func)(void *), void *data)
{
pcpu_delegate(&pcpu_devices[0], func, data,
pcpu_devices->panic_stack + PAGE_SIZE);
pcpu_devices->lowcore->panic_stack -
PANIC_FRAME_OFFSET + PAGE_SIZE);
}
int smp_find_processor_id(u16 address)
@ -935,10 +940,6 @@ void __init smp_prepare_boot_cpu(void)
pcpu->state = CPU_STATE_CONFIGURED;
pcpu->address = stap();
pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
S390_lowcore.percpu_offset = __per_cpu_offset[0];
smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
set_cpu_present(0, true);
@ -1078,8 +1079,7 @@ static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
void *hcpu)
{
unsigned int cpu = (unsigned int)(long)hcpu;
struct cpu *c = pcpu_devices[cpu].cpu;
struct device *s = &c->dev;
struct device *s = &per_cpu(cpu_device, cpu)->dev;
int err = 0;
switch (action & ~CPU_TASKS_FROZEN) {
@ -1102,7 +1102,7 @@ static int smp_add_present_cpu(int cpu)
c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return -ENOMEM;
pcpu_devices[cpu].cpu = c;
per_cpu(cpu_device, cpu) = c;
s = &c->dev;
c->hotpluggable = 1;
rc = register_cpu(c, cpu);