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freebsd-skq/sys/i386/include/pcpu.h
Konstantin Belousov ded29bd9a5 Optimize i386 pmap_extract_and_hold(). 
In particular, stop using pmap_pte() to read non-promoted pte while
walking the page table.  pmap_pte() needs to shoot down the kernel
mapping globally which causes IPI broadcast.  Since
pmap_extract_and_hold() is used for slow copyin(9), it is very
significant hit for the 4/4 kernels.

Instead, create single purpose per-processor page frame and use it to
locally map page table page inside the critical section, to avoid
reuse of the frame by other thread if context switched.

Measurement demostrated very significant improvements in any load that
utilizes copyin/copyout.

Found and benchmarked by:	bde
Sponsored by:	The FreeBSD Foundation
2018-05-25 16:29:22 +00:00

257 lines
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) Peter Wemm
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_PCPU_H_
#define _MACHINE_PCPU_H_
#ifndef _SYS_CDEFS_H_
#error "sys/cdefs.h is a prerequisite for this file"
#endif
#include <machine/segments.h>
#include <machine/tss.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
/*
* The SMP parts are setup in pmap.c and machdep.c for the BSP, and
* pmap.c and mp_machdep.c sets up the data for the AP's to "see" when
* they awake. The reason for doing it via a struct is so that an
* array of pointers to each CPU's data can be set up for things like
* "check curproc on all other processors"
*/
#define PCPU_MD_FIELDS \
char pc_monitorbuf[128] __aligned(128); /* cache line */ \
struct pcpu *pc_prvspace; /* Self-reference */ \
struct pmap *pc_curpmap; \
struct segment_descriptor pc_common_tssd; \
struct segment_descriptor *pc_tss_gdt; \
struct segment_descriptor *pc_fsgs_gdt; \
struct i386tss *pc_common_tssp; \
u_int pc_kesp0; \
u_int pc_trampstk; \
int pc_currentldt; \
u_int pc_acpi_id; /* ACPI CPU id */ \
u_int pc_apic_id; \
int pc_private_tss; /* Flag indicating private tss*/\
u_int pc_cmci_mask; /* MCx banks for CMCI */ \
u_int pc_vcpu_id; /* Xen vCPU ID */ \
struct mtx pc_cmap_lock; \
void *pc_cmap_pte1; \
void *pc_cmap_pte2; \
caddr_t pc_cmap_addr1; \
caddr_t pc_cmap_addr2; \
vm_offset_t pc_qmap_addr; /* KVA for temporary mappings */\
vm_offset_t pc_copyout_maddr; \
vm_offset_t pc_copyout_saddr; \
struct mtx pc_copyout_mlock; \
struct sx pc_copyout_slock; \
char *pc_copyout_buf; \
vm_offset_t pc_pmap_eh_va; \
caddr_t pc_pmap_eh_ptep; \
uint32_t pc_smp_tlb_done; /* TLB op acknowledgement */ \
uint32_t pc_ibpb_set; \
char __pad[538]
#ifdef _KERNEL
#if defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF)
/*
* Evaluates to the byte offset of the per-cpu variable name.
*/
#define __pcpu_offset(name) \
__offsetof(struct pcpu, name)
/*
* Evaluates to the type of the per-cpu variable name.
*/
#define __pcpu_type(name) \
__typeof(((struct pcpu *)0)->name)
/*
* Evaluates to the address of the per-cpu variable name.
*/
#define __PCPU_PTR(name) __extension__ ({ \
__pcpu_type(name) *__p; \
\
__asm __volatile("movl %%fs:%1,%0; addl %2,%0" \
: "=r" (__p) \
: "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace))), \
"i" (__pcpu_offset(name))); \
\
__p; \
})
/*
* Evaluates to the value of the per-cpu variable name.
*/
#define __PCPU_GET(name) __extension__ ({ \
__pcpu_type(name) __res; \
struct __s { \
u_char __b[MIN(sizeof(__res), 4)]; \
} __s; \
\
if (sizeof(__res) == 1 || sizeof(__res) == 2 || \
sizeof(__res) == 4) { \
__asm __volatile("mov %%fs:%1,%0" \
: "=r" (__s) \
: "m" (*(struct __s *)(__pcpu_offset(name)))); \
*(struct __s *)(void *)&__res = __s; \
} else { \
__res = *__PCPU_PTR(name); \
} \
__res; \
})
/*
* Adds a value of the per-cpu counter name. The implementation
* must be atomic with respect to interrupts.
*/
#define __PCPU_ADD(name, val) do { \
__pcpu_type(name) __val; \
struct __s { \
u_char __b[MIN(sizeof(__val), 4)]; \
} __s; \
\
__val = (val); \
if (sizeof(__val) == 1 || sizeof(__val) == 2 || \
sizeof(__val) == 4) { \
__s = *(struct __s *)(void *)&__val; \
__asm __volatile("add %1,%%fs:%0" \
: "=m" (*(struct __s *)(__pcpu_offset(name))) \
: "r" (__s)); \
} else \
*__PCPU_PTR(name) += __val; \
} while (0)
/*
* Increments the value of the per-cpu counter name. The implementation
* must be atomic with respect to interrupts.
*/
#define __PCPU_INC(name) do { \
CTASSERT(sizeof(__pcpu_type(name)) == 1 || \
sizeof(__pcpu_type(name)) == 2 || \
sizeof(__pcpu_type(name)) == 4); \
if (sizeof(__pcpu_type(name)) == 1) { \
__asm __volatile("incb %%fs:%0" \
: "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
: "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
} else if (sizeof(__pcpu_type(name)) == 2) { \
__asm __volatile("incw %%fs:%0" \
: "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
: "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
} else if (sizeof(__pcpu_type(name)) == 4) { \
__asm __volatile("incl %%fs:%0" \
: "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
: "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
} \
} while (0)
/*
* Sets the value of the per-cpu variable name to value val.
*/
#define __PCPU_SET(name, val) do { \
__pcpu_type(name) __val; \
struct __s { \
u_char __b[MIN(sizeof(__val), 4)]; \
} __s; \
\
__val = (val); \
if (sizeof(__val) == 1 || sizeof(__val) == 2 || \
sizeof(__val) == 4) { \
__s = *(struct __s *)(void *)&__val; \
__asm __volatile("mov %1,%%fs:%0" \
: "=m" (*(struct __s *)(__pcpu_offset(name))) \
: "r" (__s)); \
} else { \
*__PCPU_PTR(name) = __val; \
} \
} while (0)
#define get_pcpu() __extension__ ({ \
struct pcpu *__pc; \
\
__asm __volatile("movl %%fs:%1,%0" \
: "=r" (__pc) \
: "m" (*(struct pcpu *)(__pcpu_offset(pc_prvspace)))); \
__pc; \
})
#define PCPU_GET(member) __PCPU_GET(pc_ ## member)
#define PCPU_ADD(member, val) __PCPU_ADD(pc_ ## member, val)
#define PCPU_INC(member) __PCPU_INC(pc_ ## member)
#define PCPU_PTR(member) __PCPU_PTR(pc_ ## member)
#define PCPU_SET(member, val) __PCPU_SET(pc_ ## member, val)
#define OFFSETOF_CURTHREAD 0
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wnull-dereference"
#endif
static __inline __pure2 struct thread *
__curthread(void)
{
struct thread *td;
__asm("movl %%fs:%1,%0" : "=r" (td)
: "m" (*(char *)OFFSETOF_CURTHREAD));
return (td);
}
#ifdef __clang__
#pragma clang diagnostic pop
#endif
#define curthread (__curthread())
#define OFFSETOF_CURPCB 16
static __inline __pure2 struct pcb *
__curpcb(void)
{
struct pcb *pcb;
__asm("movl %%fs:%1,%0" : "=r" (pcb) : "m" (*(char *)OFFSETOF_CURPCB));
return (pcb);
}
#define curpcb (__curpcb())
#define IS_BSP() (PCPU_GET(cpuid) == 0)
#else /* defined(__GNUCLIKE_ASM) && defined(__GNUCLIKE___TYPEOF) */
#error "this file needs to be ported to your compiler"
#endif /* __GNUCLIKE_ASM etc. */
#endif /* _KERNEL */
#endif /* !_MACHINE_PCPU_H_ */
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