diff options
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index ef3a2cd3fe64..38e2b2a470a5 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -241,24 +241,31 @@ static ssize_t __init setup_pcpu_remap(size_t static_size) * Embedding allocator * * The first chunk is sized to just contain the static area plus - * PERCPU_DYNAMIC_RESERVE and allocated as a contiguous area using - * bootmem allocator and used as-is without being mapped into vmalloc - * area. This enables the first chunk to piggy back on the linear - * physical PMD mapping and doesn't add any additional pressure to - * TLB. + * module and dynamic reserves, and allocated as a contiguous area + * using bootmem allocator and used as-is without being mapped into + * vmalloc area. This enables the first chunk to piggy back on the + * linear physical PMD mapping and doesn't add any additional pressure + * to TLB. Note that if the needed size is smaller than the minimum + * unit size, the leftover is returned to the bootmem allocator. */ static void *pcpue_ptr __initdata; +static size_t pcpue_size __initdata; static size_t pcpue_unit_size __initdata; static struct page * __init pcpue_get_page(unsigned int cpu, int pageno) { - return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size - + ((size_t)pageno << PAGE_SHIFT)); + size_t off = (size_t)pageno << PAGE_SHIFT; + + if (off >= pcpue_size) + return NULL; + + return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size + off); } static ssize_t __init setup_pcpu_embed(size_t static_size) { unsigned int cpu; + size_t dyn_size; /* * If large page isn't supported, there's no benefit in doing @@ -269,25 +276,30 @@ static ssize_t __init setup_pcpu_embed(size_t static_size) return -EINVAL; /* allocate and copy */ - pcpue_unit_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE); - pcpue_unit_size = max_t(size_t, pcpue_unit_size, PCPU_MIN_UNIT_SIZE); + pcpue_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE); + pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE); + dyn_size = pcpue_size - static_size; + pcpue_ptr = pcpu_alloc_bootmem(0, num_possible_cpus() * pcpue_unit_size, PAGE_SIZE); if (!pcpue_ptr) return -ENOMEM; - for_each_possible_cpu(cpu) - memcpy(pcpue_ptr + cpu * pcpue_unit_size, __per_cpu_load, - static_size); + for_each_possible_cpu(cpu) { + void *ptr = pcpue_ptr + cpu * pcpue_unit_size; + + free_bootmem(__pa(ptr + pcpue_size), + pcpue_unit_size - pcpue_size); + memcpy(ptr, __per_cpu_load, static_size); + } /* we're ready, commit */ pr_info("PERCPU: Embedded %zu pages at %p, static data %zu bytes\n", - pcpue_unit_size >> PAGE_SHIFT, pcpue_ptr, static_size); + pcpue_size >> PAGE_SHIFT, pcpue_ptr, static_size); return pcpu_setup_first_chunk(pcpue_get_page, static_size, - pcpue_unit_size, - pcpue_unit_size - static_size, pcpue_ptr, - NULL); + pcpue_unit_size, dyn_size, + pcpue_ptr, NULL); } /* |