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Use pmap_bootstrap_valloc and simplify. By the way, I think the cache

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stuff is wrong, since the pte is not necessarily aligned to 64 bytes, so
nothing guarantees there is no false sharing.
This commit is contained in:
maxv 2016-12-17 13:43:33 +00:00
parent 1b6aaa82cd
commit 663ef5ea2b
1 changed files with 24 additions and 37 deletions
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61
sys/arch/x86/x86/pmap.c
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@ -1,4 +1,4 @@
/* $NetBSD: pmap.c,v 1.232 2016/12/16 19:52:22 maxv Exp $ */
/* $NetBSD: pmap.c,v 1.233 2016/12/17 13:43:33 maxv Exp $ */
/*-
* Copyright (c) 2008, 2010, 2016 The NetBSD Foundation, Inc.
@ -171,7 +171,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.232 2016/12/16 19:52:22 maxv Exp $");
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.233 2016/12/17 13:43:33 maxv Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@ -1351,46 +1351,33 @@ pmap_bootstrap(vaddr_t kva_start)
/*
* Now we allocate the "special" VAs which are used for tmp mappings
* by the pmap (and other modules). We allocate the VAs by advancing
* virtual_avail (note that there are no pages mapped at these VAs).
* we find the PTE that maps the allocated VA via the linear PTE
* mapping.
* by pmap. We allocate the VAs, and find the PTE that maps them via
* the linear PTE mapping.
*/
pt_entry_t *pte = PTE_BASE + pl1_i(virtual_avail);
vaddr_t cpuva_base;
pt_entry_t *pte;
#ifdef MULTIPROCESSOR
/*
* Waste some VA space to avoid false sharing of cache lines
* for page table pages: Give each possible CPU a cache line
* of PTE's (8) to play with, though we only need 4. We could
* recycle some of this waste by putting the idle stacks here
* as well; we could waste less space if we knew the largest
* CPU ID beforehand.
* Waste some VA space to avoid false sharing of cache lines for page
* table pages: give each possible CPU a cache line of 8 PTEs to play
* with, though we only need 4.
*/
csrcp = (char *) virtual_avail; csrc_pte = pte;
cdstp = (char *) virtual_avail+PAGE_SIZE; cdst_pte = pte+1;
zerop = (char *) virtual_avail+PAGE_SIZE*2; zero_pte = pte+2;
ptpp = (char *) virtual_avail+PAGE_SIZE*3; ptp_pte = pte+3;
virtual_avail += PAGE_SIZE * maxcpus * NPTECL;
pte += maxcpus * NPTECL;
cpuva_base = pmap_bootstrap_valloc(maxcpus * NPTECL);
#else
csrcp = (void *) virtual_avail; csrc_pte = pte; /* allocate */
virtual_avail += PAGE_SIZE; pte++; /* advance */
cdstp = (void *) virtual_avail; cdst_pte = pte;
virtual_avail += PAGE_SIZE; pte++;
zerop = (void *) virtual_avail; zero_pte = pte;
virtual_avail += PAGE_SIZE; pte++;
ptpp = (void *) virtual_avail; ptp_pte = pte;
virtual_avail += PAGE_SIZE; pte++;
cpuva_base = pmap_bootstrap_valloc(4);
#endif
pte = PTE_BASE + pl1_i(cpuva_base);
/* Values used to index the array */
csrcp = (char *)cpuva_base;
csrc_pte = pte;
cdstp = (char *)cpuva_base + PAGE_SIZE;
cdst_pte = pte + 1;
zerop = (char *)cpuva_base + PAGE_SIZE * 2;
zero_pte = pte + 2;
ptpp = (char *)cpuva_base + PAGE_SIZE * 3;
ptp_pte = pte + 3;
if (VM_MIN_KERNEL_ADDRESS == KERNBASE) {
early_zerop = zerop;
@ -3152,8 +3139,8 @@ pmap_copy_page(paddr_t srcpa, paddr_t dstpa)
kpreempt_disable();
id = cpu_number();
spte = PTESLEW(csrc_pte,id);
dpte = PTESLEW(cdst_pte,id);
spte = PTESLEW(csrc_pte, id);
dpte = PTESLEW(cdst_pte, id);
csrcva = VASLEW(csrcp, id);
cdstva = VASLEW(cdstp, id);