From fe8e0c25cad28e8858ecfa5863333c70685a6811 Mon Sep 17 00:00:00 2001 From: Alexander van Heukelum Date: Mon, 6 Sep 2010 20:53:42 +0200 Subject: x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE The irq stacks, located in the percpu-area, need to be THREAD_SIZE aligned. Add the infrastucture to align percpu variables to larger-than-pagesize amounts within the percpu area, and use it to specify the alignment for the irq stacks. Also align the percpu area itself to THREAD_SIZE. This should make irq stacks work with 8K THREAD_SIZE. Signed-off-by: Alexander van Heukelum Cc: Tejun Heo Cc: hch@lst.de LKML-Reference: <1283799222.15941.1393621887@webmail.messagingengine.com> Signed-off-by: Ingo Molnar --- include/linux/percpu-defs.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/percpu-defs.h') diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index ce2dc655cd1d..ab20d119a85d 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -138,6 +138,18 @@ DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ __aligned(PAGE_SIZE) +/* + * Declaration/definition used for large per-CPU variables that must be + * aligned to something larger than the pagesize. + */ +#define DECLARE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ + DECLARE_PER_CPU_SECTION(type, name, "..page_aligned") \ + __aligned(size) + +#define DEFINE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ + DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ + __aligned(size) + /* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to -- cgit v1.2.3 From c957ef2c59e952803766ddc22e89981ab534606f Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 20 Oct 2010 11:07:02 +0800 Subject: percpu: Introduce a read-mostly percpu API Add a new readmostly percpu section and API. This can be used to avoid dirtying data lines which are generally not written to, which is especially important for data which may be accessed by processors other than the one for which the percpu area belongs to. [ hpa: moved it *after* the page-aligned section, for obvious reasons. ] Signed-off-by: Shaohua Li LKML-Reference: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com> Cc: Eric Dumazet Signed-off-by: H. Peter Anvin --- include/asm-generic/vmlinux.lds.h | 4 ++++ include/linux/percpu-defs.h | 9 +++++++++ 2 files changed, 13 insertions(+) (limited to 'include/linux/percpu-defs.h') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8a92a170fb7d..d7e7b21511b1 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -677,7 +677,9 @@ - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__per_cpu_start) = .; \ *(.data..percpu..first) \ + . = ALIGN(PAGE_SIZE); \ *(.data..percpu..page_aligned) \ + *(.data..percpu..readmostly) \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ VMLINUX_SYMBOL(__per_cpu_end) = .; \ @@ -703,6 +705,8 @@ VMLINUX_SYMBOL(__per_cpu_load) = .; \ VMLINUX_SYMBOL(__per_cpu_start) = .; \ *(.data..percpu..first) \ + . = ALIGN(PAGE_SIZE); \ + *(.data..percpu..readmostly) \ *(.data..percpu..page_aligned) \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index ce2dc655cd1d..27ef6b190ea6 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -138,6 +138,15 @@ DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ __aligned(PAGE_SIZE) +/* + * Declaration/definition used for per-CPU variables that must be read mostly. + */ +#define DECLARE_PER_CPU_READ_MOSTLY(type, name) \ + DECLARE_PER_CPU_SECTION(type, name, "..readmostly") + +#define DEFINE_PER_CPU_READ_MOSTLY(type, name) \ + DEFINE_PER_CPU_SECTION(type, name, "..readmostly") + /* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to -- cgit v1.2.3 From 47f19a0814e80e1d4e5c17d61b70fca85ea09162 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 27 Oct 2010 17:41:17 +0200 Subject: percpu: Remove the multi-page alignment facility [DECLARE|DEFINE]_PER_CPU_MULTIPAGE_ALIGNED never really worked because the head percpu section was only page aligned. Now that the last user is gone (32-bit IRQ stacks), remove the generic percpu facility. Cc: Brian Gerst Acked-by: Tejun Heo Acked-by: Linus Torvalds LKML-Reference: <1288158182-1753-1-git-send-email-brgerst@gmail.com> Signed-off-by: Ingo Molnar --- include/linux/percpu-defs.h | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'include/linux/percpu-defs.h') diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 018db9a62ffe..27ef6b190ea6 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -147,18 +147,6 @@ #define DEFINE_PER_CPU_READ_MOSTLY(type, name) \ DEFINE_PER_CPU_SECTION(type, name, "..readmostly") -/* - * Declaration/definition used for large per-CPU variables that must be - * aligned to something larger than the pagesize. - */ -#define DECLARE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ - DECLARE_PER_CPU_SECTION(type, name, "..page_aligned") \ - __aligned(size) - -#define DEFINE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ - DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ - __aligned(size) - /* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to -- cgit v1.2.3