From 63cc8c75156462d4b42cbdd76c293b7eee7ddbfe Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 12 May 2008 15:44:40 +0200 Subject: percpu: introduce DEFINE_PER_CPU_PAGE_ALIGNED() macro While examining holes in percpu section I found this : c05f5000 D per_cpu__current_task c05f5000 D __per_cpu_start c05f5004 D per_cpu__cpu_number c05f5008 D per_cpu__irq_regs c05f500c d per_cpu__cpu_devices c05f5040 D per_cpu__cyc2ns c05f6000 d per_cpu__cpuid4_info c05f6004 d per_cpu__cache_kobject c05f6008 d per_cpu__index_kobject c05f7000 D per_cpu__gdt_page This is because gdt_page is a percpu variable, defined with a page alignement, and linker is doing its job, two times because of .o nesting in the build process. I introduced a new macro DEFINE_PER_CPU_PAGE_ALIGNED() to avoid wasting this space. All page aligned variables (only one at this time) are put in a separate subsection .data.percpu.page_aligned, at the very begining of percpu zone. Before patch , on a x86_32 machine : .data.percpu 30232 3227471872 .data.percpu 22168 3227471872 Thats 8064 bytes saved for each CPU. Signed-off-by: Eric Dumazet Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/percpu.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 4cdd393e71e1..2edacc8e6b8b 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -23,12 +23,19 @@ __attribute__((__section__(SHARED_ALIGNED_SECTION))) \ PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name \ ____cacheline_aligned_in_smp + +#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ + __attribute__((__section__(".data.percpu.page_aligned"))) \ + PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name #else #define DEFINE_PER_CPU(type, name) \ PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ DEFINE_PER_CPU(type, name) + +#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ + DEFINE_PER_CPU(type, name) #endif #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) -- cgit v1.2.3 From 268364a0f48aee2f851f9d1ef8a6cda0f3039ef1 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 4 Sep 2008 21:02:44 +0200 Subject: IO resources: add reserve_region_with_split() add reserve_region_with_split() to not lose e820 reserved entries if they overlap with existing IO regions: with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 - we get: e0000000-efffffff : PCI MMCONFIG 0 e0000000-efffffff : reserved and in /proc/iomem we get: found conflict for reserved [dd800000, efffffff], try to reserve with split __reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff] __reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff] initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs in dmesg various fixes and improvements suggested by Linus. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- include/linux/ioport.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 8d3b7a9afd17..fded376b94e3 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -108,6 +108,9 @@ extern struct resource iomem_resource; extern int request_resource(struct resource *root, struct resource *new); extern int release_resource(struct resource *new); +extern void reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name); extern int insert_resource(struct resource *parent, struct resource *new); extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new); extern int allocate_resource(struct resource *root, struct resource *new, -- cgit v1.2.3