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mmap(): faster pre-allocation for anonymous private mappings

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This commit is contained in:
Balazs Gerofi
2016-12-30 17:18:44 +09:00
parent ec75095073
commit 47a8b5bda5
1 changed files with 37 additions and 15 deletions
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52
kernel/syscall.c
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@ -1152,6 +1152,7 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
struct process *proc = thread->proc;
struct mckfd *fdp = NULL;
int pgshift;
struct vm_range *range = NULL;
dkprintf("do_mmap(%lx,%lx,%x,%x,%d,%lx)\n",
addr0, len0, prot, flags, fd, off0);
@ -1235,8 +1236,8 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
vrflags |= (flags & MAP_LOCKED)? VR_LOCKED: 0;
vrflags |= VR_DEMAND_PAGING;
if (flags & MAP_ANONYMOUS) {
if (!anon_on_demand) {
populated_mapping = 1;
if (!anon_on_demand && (flags & MAP_PRIVATE)) {
vrflags &= ~VR_DEMAND_PAGING;
}
#ifdef USE_NOCACHE_MMAP
#define X_MAP_NOCACHE MAP_32BIT
@ -1253,6 +1254,8 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
/* XXX: Intel MPI 128MB mapping.. */
if (len == 134217728) {
kprintf("%s: 128MB mapping -> no prefault\n",
__FUNCTION__, len);
populated_mapping = 0;
}
@ -1310,19 +1313,35 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
goto out;
}
}
/* Prepopulated ANONYMOUS mapping */
else if (!(vrflags & VR_DEMAND_PAGING)
&& ((vrflags & VR_PROT_MASK) != VR_PROT_NONE)) {
npages = len >> PAGE_SHIFT;
p = ihk_mc_alloc_aligned_pages(npages, p2align, IHK_MC_AP_NOWAIT);
if (p == NULL) {
ekprintf("do_mmap:allocate_pages(%d,%d) failed.\n",
ekprintf("%s: warning: failed to allocate %d contiguous pages"
" (pgshift: %d), enabling demand paging\n",
__FUNCTION__,
npages, p2align);
error = -ENOMEM;
goto out;
/* Give demand paging a chance */
vrflags |= VR_DEMAND_PAGING;
populated_mapping = 0;
error = zeroobj_create(&memobj);
if (error) {
ekprintf("%s: zeroobj_create failed, error: %d\n",
__FUNCTION__, error);
goto out;
}
}
else {
dkprintf("%s: 0x%x:%lu MAP_ANONYMOUS "
"allocated %d pages, p2align: %lx\n",
__FUNCTION__, addr, len, npages, p2align);
phys = virt_to_phys(p);
}
dkprintf("%s: 0x%x:%lu allocated %d pages, p2align: %lx\n",
__FUNCTION__, addr, len, npages, p2align);
phys = virt_to_phys(p);
}
else if (flags & MAP_SHARED) {
memset(&ads, 0, sizeof(ads));
@ -1355,7 +1374,7 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
vrflags |= VRFLAG_PROT_TO_MAXPROT(PROT_TO_VR_FLAG(maxprot));
error = add_process_memory_range(thread->vm, addr, addr+len, phys,
vrflags, memobj, off, pgshift, NULL);
vrflags, memobj, off, pgshift, &range);
if (error) {
kprintf("%s: add_process_memory_range failed for 0x%lx:%lu"
" flags: %lx, vrflags: %lx, pgshift: %d, error: %d\n",
@ -1364,15 +1383,18 @@ do_mmap(const intptr_t addr0, const size_t len0, const int prot,
goto out;
}
/* Determine pre-populated size */
populate_len = len;
memobj_lock(memobj);
if (memobj->status == MEMOBJ_TO_BE_PREFETCHED) {
memobj->status = MEMOBJ_READY;
populated_mapping = 1;
populate_len = memobj->size;
if (!(flags & MAP_ANONYMOUS)) {
memobj_lock(memobj);
if (memobj->status == MEMOBJ_TO_BE_PREFETCHED) {
memobj->status = MEMOBJ_READY;
populated_mapping = 1;
populate_len = memobj->size;
}
memobj_unlock(memobj);
}
memobj_unlock(memobj);
error = 0;
p = NULL;