Commit b6e3590f authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Andi Kleen

[PATCH] x86: Allow percpu variables to be page-aligned

Let's allow page-alignment in general for per-cpu data (wanted by Xen, and
Ingo suggested KVM as well).

Because larger alignments can use more room, we increase the max per-cpu
memory to 64k rather than 32k: it's getting a little tight.
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent de90c5ce
......@@ -69,7 +69,7 @@ SECTIONS
. = ALIGN(8);
SECURITY_INIT
. = ALIGN(64);
. = ALIGN(8192);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -59,7 +59,7 @@ SECTIONS
usr/built-in.o(.init.ramfs)
__initramfs_end = .;
#endif
. = ALIGN(64);
. = ALIGN(4096);
__per_cpu_start = .;
*(.data.percpu)
__per_cpu_end = .;
......
......@@ -91,6 +91,7 @@ SECTIONS
}
SECURITY_INIT
. = ALIGN (8192);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -57,6 +57,7 @@ SECTIONS
__alt_instructions_end = .;
.altinstr_replacement : { *(.altinstr_replacement) }
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -194,7 +194,7 @@ SECTIONS
__initramfs_end = .;
}
#endif
. = ALIGN(L1_CACHE_BYTES);
. = ALIGN(4096);
.data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) {
__per_cpu_start = .;
*(.data.percpu)
......
......@@ -110,7 +110,7 @@ SECTIONS
__initramfs_end = .;
#endif
. = ALIGN(32);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -119,7 +119,7 @@ SECTIONS
.init.ramfs : { *(.init.ramfs) }
__initramfs_end = .;
#endif
. = ALIGN(32);
. = ALIGN(_PAGE_SIZE);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -181,7 +181,7 @@ SECTIONS
.init.ramfs : { *(.init.ramfs) }
__initramfs_end = .;
#endif
. = ALIGN(32);
. = ALIGN(ASM_PAGE_SIZE);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -582,14 +582,14 @@ void __init setup_per_cpu_areas(void)
char *ptr;
/* Copy section for each CPU (we discard the original) */
size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
size = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);
#ifdef CONFIG_MODULES
if (size < PERCPU_ENOUGH_ROOM)
size = PERCPU_ENOUGH_ROOM;
#endif
for_each_possible_cpu(i) {
ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size);
ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);
if (!ptr)
panic("Cannot allocate cpu data for CPU %d\n", i);
......
......@@ -139,11 +139,7 @@ SECTIONS
__initramfs_end = .;
}
#endif
#ifdef CONFIG_PPC32
. = ALIGN(32);
#else
. = ALIGN(128);
#endif
. = ALIGN(PAGE_SIZE);
.data.percpu : {
__per_cpu_start = .;
*(.data.percpu)
......
......@@ -130,7 +130,7 @@ SECTIONS
__ftr_fixup : { *(__ftr_fixup) }
__stop___ftr_fixup = .;
. = ALIGN(32);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -107,7 +107,7 @@ SECTIONS
. = ALIGN(2);
__initramfs_end = .;
#endif
. = ALIGN(256);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -54,7 +54,7 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
.data.page_aligned : { *(.data.page_aligned) }
. = ALIGN(L1_CACHE_BYTES);
. = ALIGN(PAGE_SIZE);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -85,7 +85,7 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
.data.page_aligned : C_PHYS(.data.page_aligned) { *(.data.page_aligned) }
. = ALIGN(L1_CACHE_BYTES);
. = ALIGN(PAGE_SIZE);
__per_cpu_start = .;
.data.percpu : C_PHYS(.data.percpu) { *(.data.percpu) }
__per_cpu_end = . ;
......
......@@ -65,7 +65,7 @@ SECTIONS
__initramfs_end = .;
#endif
. = ALIGN(32);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -1343,11 +1343,11 @@ void __init setup_per_cpu_areas(void)
/* Copy section for each CPU (we discard the original) */
goal = PERCPU_ENOUGH_ROOM;
__per_cpu_shift = 0;
for (size = 1UL; size < goal; size <<= 1UL)
__per_cpu_shift = PAGE_SHIFT;
for (size = PAGE_SIZE; size < goal; size <<= 1UL)
__per_cpu_shift++;
ptr = alloc_bootmem(size * NR_CPUS);
ptr = alloc_bootmem_pages(size * NR_CPUS);
__per_cpu_base = ptr - __per_cpu_start;
......
......@@ -103,9 +103,9 @@ void __init setup_per_cpu_areas(void)
if (!NODE_DATA(cpu_to_node(i))) {
printk("cpu with no node %d, num_online_nodes %d\n",
i, num_online_nodes());
ptr = alloc_bootmem(size);
ptr = alloc_bootmem_pages(size);
} else {
ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size);
ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);
}
if (!ptr)
panic("Cannot allocate cpu data for CPU %d\n", i);
......
......@@ -195,7 +195,7 @@ SECTIONS
__initramfs_end = .;
#endif
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -198,7 +198,7 @@ SECTIONS
__ftr_fixup : { *(__ftr_fixup) }
__stop___ftr_fixup = .;
. = ALIGN(32);
. = ALIGN(4096);
__per_cpu_start = .;
.data.percpu : { *(.data.percpu) }
__per_cpu_end = .;
......
......@@ -369,12 +369,8 @@ static void __init setup_per_cpu_areas(void)
unsigned long nr_possible_cpus = num_possible_cpus();
/* Copy section for each CPU (we discard the original) */
size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
#ifdef CONFIG_MODULES
if (size < PERCPU_ENOUGH_ROOM)
size = PERCPU_ENOUGH_ROOM;
#endif
ptr = alloc_bootmem(size * nr_possible_cpus);
size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
ptr = alloc_bootmem_pages(size * nr_possible_cpus);
for_each_possible_cpu(i) {
__per_cpu_offset[i] = ptr - __per_cpu_start;
......
......@@ -346,10 +346,10 @@ static void *percpu_modalloc(unsigned long size, unsigned long align,
unsigned int i;
void *ptr;
if (align > SMP_CACHE_BYTES) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
name, align, SMP_CACHE_BYTES);
align = SMP_CACHE_BYTES;
if (align > PAGE_SIZE) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
ptr = __per_cpu_start;
......
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