Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932246AbVKKIjo (ORCPT ); Fri, 11 Nov 2005 03:39:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932253AbVKKIj2 (ORCPT ); Fri, 11 Nov 2005 03:39:28 -0500 Received: from i121.durables.org ([64.81.244.121]:9166 "EHLO waste.org") by vger.kernel.org with ESMTP id S932233AbVKKIgH (ORCPT ); Fri, 11 Nov 2005 03:36:07 -0500 Date: Fri, 11 Nov 2005 02:35:53 -0600 From: Matt Mackall To: Andrew Morton , linux-kernel@vger.kernel.org X-PatchBomber: http://selenic.com/scripts/mailpatches In-Reply-To: <9.282480653@selenic.com> Message-Id: <10.282480653@selenic.com> Subject: [PATCH 9/15] misc: Make sysenter support optional Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5630 Lines: 161 This adds configurable sysenter support on x86. This saves about 5k on small systems. text data bss dec hex 3330172 529036 190556 4049764 3dcb64 baseline 3329604 524164 190556 4044324 3db624 sysenter $ bloat-o-meter vmlinux{-baseline,} add/remove: 0/2 grow/shrink: 0/3 up/down: 0/-316 (-316) function old new delta __restore_processor_state 76 62 -14 identify_cpu 520 500 -20 create_elf_tables 923 883 -40 sysenter_setup 113 - -113 enable_sep_cpu 129 - -129 Most of the savings is not including the vsyscall DSO which doesn't show up with bloat-o-meter: $ size arch/i386/kernel/vsyscall.o text data bss dec hex filename 0 4826 0 4826 12da arch/i386/kernel/vsyscall.o $ nm arch/i386/kernel/vsyscall.o 00000961 T vsyscall_int80_end 00000000 T vsyscall_int80_start 000012da T vsyscall_sysenter_end 00000961 T vsyscall_sysenter_start Signed-off-by: Matt Mackall Index: 2.6.14-misc/arch/i386/kernel/Makefile =================================================================== --- 2.6.14-misc.orig/arch/i386/kernel/Makefile 2005-11-11 00:32:13.000000000 -0800 +++ 2.6.14-misc/arch/i386/kernel/Makefile 2005-11-11 00:32:17.000000000 -0800 @@ -29,7 +29,7 @@ obj-$(CONFIG_X86_NUMAQ) += numaq.o obj-$(CONFIG_X86_SUMMIT_NUMA) += summit.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_MODULES) += module.o -obj-y += sysenter.o vsyscall.o +obj-$(CONFIG_SYSENTER) += sysenter.o vsyscall.o obj-$(CONFIG_ACPI_SRAT) += srat.o obj-$(CONFIG_HPET_TIMER) += time_hpet.o obj-$(CONFIG_EFI) += efi.o efi_stub.o Index: 2.6.14-misc/arch/i386/kernel/entry.S =================================================================== --- 2.6.14-misc.orig/arch/i386/kernel/entry.S 2005-11-11 00:32:13.000000000 -0800 +++ 2.6.14-misc/arch/i386/kernel/entry.S 2005-11-11 00:32:17.000000000 -0800 @@ -177,6 +177,7 @@ need_resched: # sysenter call handler stub ENTRY(sysenter_entry) +#ifdef CONFIG_SYSENTER movl TSS_sysenter_esp0(%esp),%esp sysenter_past_esp: sti @@ -219,7 +220,7 @@ sysenter_past_esp: xorl %ebp,%ebp sti sysexit - +#endif # system call handler stub ENTRY(system_call) @@ -506,6 +507,8 @@ device_not_available_emulate: * by hand onto the new stack - while updating the return eip past * the instruction that would have done it for sysenter. */ + +#ifdef CONFIG_SYSENTER #define FIX_STACK(offset, ok, label) \ cmpw $__KERNEL_CS,4(%esp); \ jne ok; \ @@ -514,6 +517,10 @@ label: \ pushfl; \ pushl $__KERNEL_CS; \ pushl $sysenter_past_esp +#else +#define FIX_STACK(offset, ok, label) \ +label: +#endif KPROBE_ENTRY(debug) cmpl $sysenter_entry,(%esp) Index: 2.6.14-misc/arch/i386/power/cpu.c =================================================================== --- 2.6.14-misc.orig/arch/i386/power/cpu.c 2005-11-11 00:31:55.000000000 -0800 +++ 2.6.14-misc/arch/i386/power/cpu.c 2005-11-11 00:32:17.000000000 -0800 @@ -109,11 +109,13 @@ void __restore_processor_state(struct sa loadsegment(gs, ctxt->gs); loadsegment(ss, ctxt->ss); +#ifdef CONFIG_SYSENTER /* * sysenter MSRs */ if (boot_cpu_has(X86_FEATURE_SEP)) enable_sep_cpu(); +#endif fix_processor_context(); do_fpu_end(); Index: 2.6.14-misc/include/asm-i386/elf.h =================================================================== --- 2.6.14-misc.orig/include/asm-i386/elf.h 2005-11-11 00:32:01.000000000 -0800 +++ 2.6.14-misc/include/asm-i386/elf.h 2005-11-11 00:32:17.000000000 -0800 @@ -134,11 +134,13 @@ extern int dump_task_extended_fpu (struc #define VSYSCALL_ENTRY ((unsigned long) &__kernel_vsyscall) extern void __kernel_vsyscall; +#ifdef CONFIG_SYSENTER #define ARCH_DLINFO \ do { \ NEW_AUX_ENT(AT_SYSINFO, VSYSCALL_ENTRY); \ NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL_BASE); \ } while (0) +#endif /* * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out Index: 2.6.14-misc/init/Kconfig =================================================================== --- 2.6.14-misc.orig/init/Kconfig 2005-11-11 00:32:13.000000000 -0800 +++ 2.6.14-misc/init/Kconfig 2005-11-11 00:32:17.000000000 -0800 @@ -357,6 +357,14 @@ config VM86 XFree86 to initialize some video cards via BIOS. Disabling this option saves about 6k. +config SYSENTER + depends X86 + default y + bool "Enable syscalls via sysenter" if EMBEDDED + help + Disabling this feature removes sysenter handling as well as + vsyscall fixmaps. + config CC_OPTIMIZE_FOR_SIZE bool "Optimize for size" if EMBEDDED default y if ARM || H8300 Index: 2.6.14-misc/arch/i386/kernel/cpu/common.c =================================================================== --- 2.6.14-misc.orig/arch/i386/kernel/cpu/common.c 2005-11-11 00:32:13.000000000 -0800 +++ 2.6.14-misc/arch/i386/kernel/cpu/common.c 2005-11-11 00:32:40.000000000 -0800 @@ -429,9 +429,11 @@ void __devinit identify_cpu(struct cpuin /* Init Machine Check Exception if available. */ mcheck_init(c); +#ifdef CONFIG_SYSENTER if (c == &boot_cpu_data) sysenter_setup(); enable_sep_cpu(); +#endif if (c == &boot_cpu_data) mtrr_bp_init(); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/