From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753759Ab0L0NeI (ORCPT ); Mon, 27 Dec 2010 08:34:08 -0500 Received: from mail-bw0-f46.google.com ([209.85.214.46]:42506 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752938Ab0L0NeG (ORCPT ); Mon, 27 Dec 2010 08:34:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=kx+LRx6dD+3Gb86bI4dndZimRLOUJVST7xt42ZtiHTX/X9zzi9XW0nTYVytFEG3PGG TWM5VF3Ikt9LCFv4tqqinJLapl4fvOAdI0+jQ4/tTJ1qzfsMWME4WfUsfZKAg+bG2yry e1xo5i2EHZ5YlhlOUPlQ4u+1X4Pc1n+XqYYa8= Date: Mon, 27 Dec 2010 14:34:00 +0100 From: Tejun Heo To: Shaohua Li , Sam Ravnborg , lkml , "hpa@zytor.com" , Andrew Morton , eric.dumazet@gmail.com, arch@vger.kernel.org Subject: [PATCH percpu#for-next] percpu: align percpu readmostly subsection to cacheline Message-ID: <20101227133400.GC488@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently percpu readmostly subsection may share cachelines with other percpu subsections which may result in unnecessary cacheline bounce and performance degradation. This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR() linker macros, makes each arch linker scripts specify its cacheline size and use it to align percpu subsections. This is based on Shaohua's x86 only patch. Signed-off-by: Tejun Heo Cc: Shaohua Li --- Shaohua, can you please verify this achieves the same result? If no one objects, I'll route it through the percpu tree. Thanks. arch/alpha/kernel/vmlinux.lds.S | 2 +- arch/arm/kernel/vmlinux.lds.S | 2 +- arch/blackfin/kernel/vmlinux.lds.S | 2 +- arch/cris/kernel/vmlinux.lds.S | 2 +- arch/frv/kernel/vmlinux.lds.S | 2 +- arch/ia64/kernel/vmlinux.lds.S | 2 +- arch/m32r/kernel/vmlinux.lds.S | 2 +- arch/mips/kernel/vmlinux.lds.S | 2 +- arch/mn10300/kernel/vmlinux.lds.S | 2 +- arch/parisc/kernel/vmlinux.lds.S | 2 +- arch/powerpc/kernel/vmlinux.lds.S | 2 +- arch/s390/kernel/vmlinux.lds.S | 2 +- arch/sh/kernel/vmlinux.lds.S | 2 +- arch/sparc/kernel/vmlinux.lds.S | 2 +- arch/tile/kernel/vmlinux.lds.S | 2 +- arch/um/include/asm/common.lds.S | 2 +- arch/x86/kernel/vmlinux.lds.S | 4 ++-- arch/xtensa/kernel/vmlinux.lds.S | 2 +- include/asm-generic/vmlinux.lds.h | 35 ++++++++++++++++++++++------------- 19 files changed, 41 insertions(+), 32 deletions(-) diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S index 003ef4c..173518f 100644 --- a/arch/alpha/kernel/vmlinux.lds.S +++ b/arch/alpha/kernel/vmlinux.lds.S @@ -38,7 +38,7 @@ SECTIONS __init_begin = ALIGN(PAGE_SIZE); INIT_TEXT_SECTION(PAGE_SIZE) INIT_DATA_SECTION(16) - PERCPU(PAGE_SIZE) + PERCPU(64, PAGE_SIZE) /* Align to THREAD_SIZE rather than PAGE_SIZE here so any padding page needed for the THREAD_SIZE aligned init_task gets freed after init */ . = ALIGN(THREAD_SIZE); diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index cead889..67417d0 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -70,7 +70,7 @@ SECTIONS #endif } - PERCPU(PAGE_SIZE) + PERCPU(32, PAGE_SIZE) #ifndef CONFIG_XIP_KERNEL . = ALIGN(PAGE_SIZE); diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S index 4122678..c40d07f 100644 --- a/arch/blackfin/kernel/vmlinux.lds.S +++ b/arch/blackfin/kernel/vmlinux.lds.S @@ -136,7 +136,7 @@ SECTIONS . = ALIGN(16); INIT_DATA_SECTION(16) - PERCPU(4) + PERCPU(32, 4) .exit.data : { diff --git a/arch/cris/kernel/vmlinux.lds.S b/arch/cris/kernel/vmlinux.lds.S index 4422189..c62e134 100644 --- a/arch/cris/kernel/vmlinux.lds.S +++ b/arch/cris/kernel/vmlinux.lds.S @@ -107,7 +107,7 @@ SECTIONS #endif __vmlinux_end = .; /* Last address of the physical file. */ #ifdef CONFIG_ETRAX_ARCH_V32 - PERCPU(PAGE_SIZE) + PERCPU(32, PAGE_SIZE) .init.ramfs : { INIT_RAM_FS diff --git a/arch/frv/kernel/vmlinux.lds.S b/arch/frv/kernel/vmlinux.lds.S index 8b973f3..0daae8a 100644 --- a/arch/frv/kernel/vmlinux.lds.S +++ b/arch/frv/kernel/vmlinux.lds.S @@ -37,7 +37,7 @@ SECTIONS _einittext = .; INIT_DATA_SECTION(8) - PERCPU(4096) + PERCPU(L1_CACHE_BYTES, 4096) . = ALIGN(PAGE_SIZE); __init_end = .; diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S index 5a4d044..787de4a 100644 --- a/arch/ia64/kernel/vmlinux.lds.S +++ b/arch/ia64/kernel/vmlinux.lds.S @@ -198,7 +198,7 @@ SECTIONS { /* Per-cpu data: */ . = ALIGN(PERCPU_PAGE_SIZE); - PERCPU_VADDR(PERCPU_ADDR, :percpu) + PERCPU_VADDR(SMP_CACHE_BYTES, PERCPU_ADDR, :percpu) __phys_per_cpu_start = __per_cpu_load; /* * ensure percpu data fits diff --git a/arch/m32r/kernel/vmlinux.lds.S b/arch/m32r/kernel/vmlinux.lds.S index 7da94ea..c194d64 100644 --- a/arch/m32r/kernel/vmlinux.lds.S +++ b/arch/m32r/kernel/vmlinux.lds.S @@ -53,7 +53,7 @@ SECTIONS __init_begin = .; INIT_TEXT_SECTION(PAGE_SIZE) INIT_DATA_SECTION(16) - PERCPU(PAGE_SIZE) + PERCPU(32, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; /* freed after init ends here */ diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index f25df73..fd5d045 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -108,7 +108,7 @@ SECTIONS EXIT_DATA } - PERCPU(PAGE_SIZE) + PERCPU(1 << CONFIG_MIPS_L1_CACHE_SHIFT, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; /* freed after init ends here */ diff --git a/arch/mn10300/kernel/vmlinux.lds.S b/arch/mn10300/kernel/vmlinux.lds.S index febbeee..968bcd2 100644 --- a/arch/mn10300/kernel/vmlinux.lds.S +++ b/arch/mn10300/kernel/vmlinux.lds.S @@ -70,7 +70,7 @@ SECTIONS .exit.text : { EXIT_TEXT; } .exit.data : { EXIT_DATA; } - PERCPU(PAGE_SIZE) + PERCPU(32, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; /* freed after init ends here */ diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index d64a6bb..8f1e4ef 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -145,7 +145,7 @@ SECTIONS EXIT_DATA } - PERCPU(PAGE_SIZE) + PERCPU(L1_CACHE_BYTES, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; /* freed after init ends here */ diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 8a0deef..b9150f0 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -160,7 +160,7 @@ SECTIONS INIT_RAM_FS } - PERCPU(PAGE_SIZE) + PERCPU(L1_CACHE_BYTES, PAGE_SIZE) . = ALIGN(8); .machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) { diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index a68ac10..1bc18cd 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -77,7 +77,7 @@ SECTIONS . = ALIGN(PAGE_SIZE); INIT_DATA_SECTION(0x100) - PERCPU(PAGE_SIZE) + PERCPU(0x100, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; /* freed after init ends here */ diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S index 7f8a709..af4d461 100644 --- a/arch/sh/kernel/vmlinux.lds.S +++ b/arch/sh/kernel/vmlinux.lds.S @@ -66,7 +66,7 @@ SECTIONS __machvec_end = .; } - PERCPU(PAGE_SIZE) + PERCPU(L1_CACHE_BYTES, PAGE_SIZE) /* * .exit.text is discarded at runtime, not link time, to deal with diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S index 0c1e678..92b557a 100644 --- a/arch/sparc/kernel/vmlinux.lds.S +++ b/arch/sparc/kernel/vmlinux.lds.S @@ -108,7 +108,7 @@ SECTIONS __sun4v_2insn_patch_end = .; } - PERCPU(PAGE_SIZE) + PERCPU(SMP_CACHE_BYTES, PAGE_SIZE) . = ALIGN(PAGE_SIZE); __init_end = .; diff --git a/arch/tile/kernel/vmlinux.lds.S b/arch/tile/kernel/vmlinux.lds.S index 25fdc0c..c6ce378 100644 --- a/arch/tile/kernel/vmlinux.lds.S +++ b/arch/tile/kernel/vmlinux.lds.S @@ -63,7 +63,7 @@ SECTIONS *(.init.page) } :data =0 INIT_DATA_SECTION(16) - PERCPU(PAGE_SIZE) + PERCPU(L2_CACHE_BYTES, PAGE_SIZE) . = ALIGN(PAGE_SIZE); VMLINUX_SYMBOL(_einitdata) = .; diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S index ac55b9e..34bede8 100644 --- a/arch/um/include/asm/common.lds.S +++ b/arch/um/include/asm/common.lds.S @@ -42,7 +42,7 @@ INIT_SETUP(0) } - PERCPU(32) + PERCPU(32, 32) .initcall.init : { INIT_CALLS diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e03530a..68cf1c0 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -226,7 +226,7 @@ SECTIONS * output PHDR, so the next output section - .init.text - should * start another segment - init. */ - PERCPU_VADDR(0, :percpu) + PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu) #endif INIT_TEXT_SECTION(PAGE_SIZE) @@ -301,7 +301,7 @@ SECTIONS } #if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP) - PERCPU(THREAD_SIZE) + PERCPU(INTERNODE_CACHE_BYTES, THREAD_SIZE) #endif . = ALIGN(PAGE_SIZE); diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S index 9b52615..a282006 100644 --- a/arch/xtensa/kernel/vmlinux.lds.S +++ b/arch/xtensa/kernel/vmlinux.lds.S @@ -155,7 +155,7 @@ SECTIONS INIT_RAM_FS } - PERCPU(PAGE_SIZE) + PERCPU(XCHAL_ICACHE_LINESIZE, PAGE_SIZE) /* We need this dummy segment here */ diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bd69d79..aa1339e 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -15,7 +15,7 @@ * HEAD_TEXT_SECTION * INIT_TEXT_SECTION(PAGE_SIZE) * INIT_DATA_SECTION(...) - * PERCPU(PAGE_SIZE) + * PERCPU(CACHELINE_SIZE, PAGE_SIZE) * __init_end = .; * * _stext = .; @@ -666,13 +666,18 @@ /** * PERCPU_VADDR - define output section for percpu area + * @cacheline: cacheline size * @vaddr: explicit base address (optional) * @phdr: destination PHDR (optional) * - * Macro which expands to output section for percpu area. If @vaddr - * is not blank, it specifies explicit base address and all percpu - * symbols will be offset from the given address. If blank, @vaddr - * always equals @laddr + LOAD_OFFSET. + * Macro which expands to output section for percpu area. + * + * @cacheline is used to align subsections to avoid false cacheline + * sharing between subsections for different purposes. + * + * If @vaddr is not blank, it specifies explicit base address and all + * percpu symbols will be offset from the given address. If blank, + * @vaddr always equals @laddr + LOAD_OFFSET. * * @phdr defines the output PHDR to use if not blank. Be warned that * output PHDR is sticky. If @phdr is specified, the next output @@ -683,7 +688,7 @@ * If there is no need to put the percpu section at a predetermined * address, use PERCPU(). */ -#define PERCPU_VADDR(vaddr, phdr) \ +#define PERCPU_VADDR(cacheline, vaddr, phdr) \ VMLINUX_SYMBOL(__per_cpu_load) = .; \ .data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load) \ - LOAD_OFFSET) { \ @@ -691,7 +696,9 @@ *(.data..percpu..first) \ . = ALIGN(PAGE_SIZE); \ *(.data..percpu..page_aligned) \ + . = ALIGN(cacheline); \ *(.data..percpu..readmostly) \ + . = ALIGN(cacheline); \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ VMLINUX_SYMBOL(__per_cpu_end) = .; \ @@ -700,18 +707,18 @@ /** * PERCPU - define output section for percpu area, simple version + * @cacheline: cacheline size * @align: required alignment * - * Align to @align and outputs output section for percpu area. This - * macro doesn't maniuplate @vaddr or @phdr and __per_cpu_load and + * Align to @align and outputs output section for percpu area. This macro + * doesn't manipulate @vaddr or @phdr and __per_cpu_load and * __per_cpu_start will be identical. * - * This macro is equivalent to ALIGN(align); PERCPU_VADDR( , ) except - * that __per_cpu_load is defined as a relative symbol against - * .data..percpu which is required for relocatable x86_32 - * configuration. + * This macro is equivalent to ALIGN(@align); PERCPU_VADDR(@cacheline,,) + * except that __per_cpu_load is defined as a relative symbol against + * .data..percpu which is required for relocatable x86_32 configuration. */ -#define PERCPU(align) \ +#define PERCPU(cacheline, align) \ . = ALIGN(align); \ .data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__per_cpu_load) = .; \ @@ -719,7 +726,9 @@ *(.data..percpu..first) \ . = ALIGN(PAGE_SIZE); \ *(.data..percpu..page_aligned) \ + . = ALIGN(cacheline); \ *(.data..percpu..readmostly) \ + . = ALIGN(cacheline); \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ VMLINUX_SYMBOL(__per_cpu_end) = .; \