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vm: restartability improvements (#2)

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also allocate vm pagetables dynamic-only.

further improves restart survivability.

Change-Id: Iac44845d9bd434408b23755274fa890a7b851373
This commit is contained in:
Ben Gras 2015-01-16 16:42:28 +01:00 committed by David van Moolenbroek
parent 10e6ba68d2
commit 683f1fcab3
1 changed files with 34 additions and 6 deletions
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40
minix/servers/vm/pagetable.c
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@ -856,11 +856,6 @@ int pt_writemap(struct vmproc * vmp,
*/
assert(pt->pt_pt[pde]);
#if SANITYCHECKS
/* We don't expect to overwrite a page. */
if(!(writemapflags & (WMF_OVERWRITE|WMF_VERIFY)))
assert(!(pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT));
#endif
if(writemapflags & (WMF_WRITEFLAGSONLY|WMF_FREE)) {
#if defined(__i386__)
physaddr = pt->pt_pt[pde][pte] & ARCH_VM_ADDR_MASK;
@ -1072,12 +1067,28 @@ void pt_allocate_kernel_mapped_pagetables(void)
}
}
static void pt_copy(pt_t *dst, pt_t *src)
{
int pde;
for(pde=0; pde < kern_start_pde; pde++) {
if(!(src->pt_dir[pde] & ARCH_VM_PDE_PRESENT)) {
continue;
}
assert(!(src->pt_dir[pde] & ARCH_VM_BIGPAGE));
if(!src->pt_pt[pde]) { panic("pde %d empty\n", pde); }
if(pt_ptalloc(dst, pde, 0) != OK)
panic("pt_ptalloc failed");
memcpy(dst->pt_pt[pde], src->pt_pt[pde],
ARCH_VM_PT_ENTRIES * sizeof(*dst->pt_pt[pde]));
}
}
/*===========================================================================*
* pt_init *
*===========================================================================*/
void pt_init(void)
{
pt_t *newpt;
pt_t *newpt, newpt_dyn;
int s, r, p;
phys_bytes phys;
vir_bytes sparepages_mem;
@ -1307,6 +1318,9 @@ void pt_init(void)
* pages though, as the physical addresses will change on liveupdate. So we
* re-do part of the initialization now with purely dynamically allocated
* memory. First throw out the static pool.
*
* Then allocate the kernel-shared-pagetables and VM pagetables with dynamic
* memory.
*/
alloc_cycle(); /* Make sure allocating works */
@ -1321,6 +1335,20 @@ void pt_init(void)
panic("VMCTL_FLUSHTLB failed");
}
/* Recreate VM page table with dynamic-only allocations */
memset(&newpt_dyn, 0, sizeof(newpt_dyn));
pt_new(&newpt_dyn);
pt_copy(&newpt_dyn, newpt);
memcpy(newpt, &newpt_dyn, sizeof(*newpt));
pt_bind(newpt, &vmproc[VM_PROC_NR]); /* Recalculate */
pt_mapkernel(newpt); /* Rewrite pagetable info */
/* Flush TLB just in case any of those mappings have been touched */
if((sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
panic("VMCTL_FLUSHTLB failed");
}
/* All OK. */
return;
}