mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-01 10:46:48 +07:00
26799a6311
The pda rework (commit 3461b0af02)
to remove static boot cpu pdas introduced a performance bug.
_boot_cpu_pda is the actual pda used by the boot cpu and is definitely
not "__read_mostly" and ended up polluting the read mostly section with
writes. This bug caused regression of about 8-10% on certain syscall
intensive workloads.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Acked-by: Mike Travis <travis@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
148 lines
3.7 KiB
C
148 lines
3.7 KiB
C
/*
|
|
* prepare to run common code
|
|
*
|
|
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/linkage.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/start_kernel.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/desc.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/kdebug.h>
|
|
#include <asm/e820.h>
|
|
#include <asm/bios_ebda.h>
|
|
#include <asm/trampoline.h>
|
|
|
|
/* boot cpu pda */
|
|
static struct x8664_pda _boot_cpu_pda;
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* We install an empty cpu_pda pointer table to indicate to early users
|
|
* (numa_set_node) that the cpu_pda pointer table for cpus other than
|
|
* the boot cpu is not yet setup.
|
|
*/
|
|
static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
|
|
#else
|
|
static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
|
|
#endif
|
|
|
|
void __init x86_64_init_pda(void)
|
|
{
|
|
_cpu_pda = __cpu_pda;
|
|
cpu_pda(0) = &_boot_cpu_pda;
|
|
pda_init(0);
|
|
}
|
|
|
|
static void __init zap_identity_mappings(void)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(0UL);
|
|
pgd_clear(pgd);
|
|
__flush_tlb_all();
|
|
}
|
|
|
|
/* Don't add a printk in there. printk relies on the PDA which is not initialized
|
|
yet. */
|
|
static void __init clear_bss(void)
|
|
{
|
|
memset(__bss_start, 0,
|
|
(unsigned long) __bss_stop - (unsigned long) __bss_start);
|
|
}
|
|
|
|
static void __init copy_bootdata(char *real_mode_data)
|
|
{
|
|
char * command_line;
|
|
|
|
memcpy(&boot_params, real_mode_data, sizeof boot_params);
|
|
if (boot_params.hdr.cmd_line_ptr) {
|
|
command_line = __va(boot_params.hdr.cmd_line_ptr);
|
|
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
|
|
}
|
|
}
|
|
|
|
void __init x86_64_start_kernel(char * real_mode_data)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Build-time sanity checks on the kernel image and module
|
|
* area mappings. (these are purely build-time and produce no code)
|
|
*/
|
|
BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
|
|
BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
|
|
BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
|
|
BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
|
|
BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
|
|
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
|
|
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
|
|
(__START_KERNEL & PGDIR_MASK)));
|
|
BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
|
|
|
|
/* clear bss before set_intr_gate with early_idt_handler */
|
|
clear_bss();
|
|
|
|
/* Make NULL pointers segfault */
|
|
zap_identity_mappings();
|
|
|
|
/* Cleanup the over mapped high alias */
|
|
cleanup_highmap();
|
|
|
|
for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
|
|
#ifdef CONFIG_EARLY_PRINTK
|
|
set_intr_gate(i, &early_idt_handlers[i]);
|
|
#else
|
|
set_intr_gate(i, early_idt_handler);
|
|
#endif
|
|
}
|
|
load_idt((const struct desc_ptr *)&idt_descr);
|
|
|
|
if (console_loglevel == 10)
|
|
early_printk("Kernel alive\n");
|
|
|
|
x86_64_init_pda();
|
|
|
|
x86_64_start_reservations(real_mode_data);
|
|
}
|
|
|
|
void __init x86_64_start_reservations(char *real_mode_data)
|
|
{
|
|
copy_bootdata(__va(real_mode_data));
|
|
|
|
reserve_trampoline_memory();
|
|
|
|
reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
|
|
|
|
#ifdef CONFIG_BLK_DEV_INITRD
|
|
/* Reserve INITRD */
|
|
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
|
|
unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
|
|
unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
|
|
unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
|
|
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
|
|
}
|
|
#endif
|
|
|
|
reserve_ebda_region();
|
|
|
|
/*
|
|
* At this point everything still needed from the boot loader
|
|
* or BIOS or kernel text should be early reserved or marked not
|
|
* RAM in e820. All other memory is free game.
|
|
*/
|
|
|
|
start_kernel();
|
|
}
|