Module Name: src
Committed By: maxv
Date: Thu Jun 15 06:32:52 UTC 2017
Modified Files:
src/sys/arch/x86/x86: pmap.c
Log Message:
Reorder these loops to reduce the number of enter->flush. I figured out
yesterday that this has a clear impact: a system with 16TB of hard-coded
ram has a 4-second black screen when booting. Now we're down to < 0.5s.
It could be optimized more, but verily I don't have a machine with P1GB
right now.
To generate a diff of this commit:
cvs rdiff -u -r1.246 -r1.247 src/sys/arch/x86/x86/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/x86/pmap.c
diff -u src/sys/arch/x86/x86/pmap.c:1.246 src/sys/arch/x86/x86/pmap.c:1.247
--- src/sys/arch/x86/x86/pmap.c:1.246 Wed Jun 14 14:17:15 2017
+++ src/sys/arch/x86/x86/pmap.c Thu Jun 15 06:32:52 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.246 2017/06/14 14:17:15 maxv Exp $ */
+/* $NetBSD: pmap.c,v 1.247 2017/06/15 06:32:52 maxv Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.246 2017/06/14 14:17:15 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.247 2017/06/15 06:32:52 maxv Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -1443,8 +1443,8 @@ pmap_init_directmap(struct pmap *kpm)
pt_entry_t *pte;
pd_entry_t *pde;
phys_ram_seg_t *mc;
- size_t nL4e, nL3e;
- int i;
+ size_t nL4e, nL3e, pn, npd;
+ int i, n;
const pd_entry_t pteflags = PG_V | PG_KW | pmap_pg_nx;
@@ -1503,36 +1503,37 @@ pmap_init_directmap(struct pmap *kpm)
/* Allocate L2. */
L2page_pa = pmap_bootstrap_palloc(nL3e);
- /* Zero out the L2 pages. */
+ KASSERT(pmap_largepages != 0);
+
+ /* Large pages are supported. Just create L2. */
for (i = 0; i < nL3e; i++) {
pdp = L2page_pa + i * PAGE_SIZE;
*pte = (pdp & PG_FRAME) | pteflags;
pmap_update_pg(tmpva);
memset((void *)tmpva, 0, PAGE_SIZE);
- }
- KASSERT(pmap_largepages != 0);
-
- /* Large pages are supported. Just create L2. */
- for (i = 0; i < NPDPG * nL3e; i++) {
- pdp = (paddr_t)&(((pd_entry_t *)L2page_pa)[i]);
- *pte = (pdp & PG_FRAME) | pteflags;
- pmap_update_pg(tmpva);
-
- pde = (pd_entry_t *)(tmpva + (pdp & ~PG_FRAME));
- *pde = ((paddr_t)i << L2_SHIFT) | pteflags |
- PG_U | PG_PS | PG_G;
+ pde = (pd_entry_t *)tmpva;
+ for (n = 0; n < NPDPG; n++) {
+ pn = (i * NPDPG) + n;
+ pde[n] = ((paddr_t)pn << L2_SHIFT) | pteflags |
+ PG_U | PG_PS | PG_G;
+ }
}
/* Fill in the L3 entries, linked to L2. */
- for (i = 0; i < nL3e; i++) {
- pdp = (paddr_t)&(((pd_entry_t *)L3page_pa)[i]);
+ for (i = 0; i < nL4e; i++) {
+ pdp = L3page_pa + i * PAGE_SIZE;
*pte = (pdp & PG_FRAME) | pteflags;
pmap_update_pg(tmpva);
- pde = (pd_entry_t *)(tmpva + (pdp & ~PG_FRAME));
- *pde = (L2page_pa + (i << PAGE_SHIFT)) | pteflags | PG_U;
+ pde = (pd_entry_t *)tmpva;
+ npd = (i == nL4e - 1) ? (nL3e % NPDPG) : NPDPG;
+ for (n = 0; n < npd; n++) {
+ pn = (i * NPDPG) + n;
+ pde[n] = (L2page_pa + (pn << PAGE_SHIFT)) |
+ pteflags | PG_U;
+ }
}
}
