diff options
| author | Mike Travis <travis@sgi.com> | 2009-01-11 06:58:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-11 19:13:25 +0100 |
| commit | c7a3589e7a1f8fdbd2536fe1bfa60b37f5121c69 (patch) | |
| tree | facf804f00b7de20fd5d79dde7e46c78e3b1ed5c /drivers/xen | |
| parent | cpumask: reduce stack usage in find_lowest_rq (diff) | |
| download | linux-c7a3589e7a1f8fdbd2536fe1bfa60b37f5121c69.tar.xz linux-c7a3589e7a1f8fdbd2536fe1bfa60b37f5121c69.zip | |
Xen: reduce memory required for cpu_evtchn_mask
Impact: reduce memory usage.
Reduce this significant gain in the amount of memory used
when NR_CPUS bumped from 128 to 4096 by allocating the
array based on nr_cpu_ids:
65536 +2031616 2097152 +3100% cpu_evtchn_mask(.bss)
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: virtualization@lists.osdl.org
Cc: xen-devel@lists.xensource.com
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/events.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index e0767ff35d6c..ed7527b3745a 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -75,7 +75,14 @@ enum { static int evtchn_to_irq[NR_EVENT_CHANNELS] = { [0 ... NR_EVENT_CHANNELS-1] = -1 }; -static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG]; +struct cpu_evtchn_s { + unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG]; +}; +static struct cpu_evtchn_s *cpu_evtchn_mask_p; +static inline unsigned long *cpu_evtchn_mask(int cpu) +{ + return cpu_evtchn_mask_p[cpu].bits; +} static u8 cpu_evtchn[NR_EVENT_CHANNELS]; /* Reference counts for bindings to IRQs. */ @@ -115,7 +122,7 @@ static inline unsigned long active_evtchns(unsigned int cpu, unsigned int idx) { return (sh->evtchn_pending[idx] & - cpu_evtchn_mask[cpu][idx] & + cpu_evtchn_mask(cpu)[idx] & ~sh->evtchn_mask[idx]); } @@ -128,8 +135,8 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu) cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu)); #endif - __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]); - __set_bit(chn, cpu_evtchn_mask[cpu]); + __clear_bit(chn, cpu_evtchn_mask(cpu_evtchn[chn])); + __set_bit(chn, cpu_evtchn_mask(cpu)); cpu_evtchn[chn] = cpu; } @@ -147,7 +154,7 @@ static void init_evtchn_cpu_bindings(void) #endif memset(cpu_evtchn, 0, sizeof(cpu_evtchn)); - memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0])); + memset(cpu_evtchn_mask(0), ~0, sizeof(cpu_evtchn_mask(0))); } static inline unsigned int cpu_from_evtchn(unsigned int evtchn) @@ -822,6 +829,10 @@ static struct irq_chip xen_dynamic_chip __read_mostly = { void __init xen_init_IRQ(void) { int i; + size_t size = nr_cpu_ids * sizeof(struct cpu_evtchn_s); + + cpu_evtchn_mask_p = kmalloc(size, GFP_KERNEL); + BUG_ON(cpu_evtchn_mask == NULL); init_evtchn_cpu_bindings(); |