The patch titled
Subject: x86-64: fall back to regular page vmemmap on allocation failure
has been added to the -mm tree. Its filename is
x86-64-fall-back-to-regular-page-vmemmap-on-allocation-failure.patch
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: x86-64: fall back to regular page vmemmap on allocation failure
Memory hotplug can happen on a machine under load, memory shortness
and fragmentation, so huge page allocations for the vmemmap are not
guaranteed to succeed.
Try to fall back to regular pages before failing the hotplug event
completely.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Bernhard Schmidt <Bernhard.Schmidt@xxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: "Luck, Tony" <tony.luck@xxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/init_64.c | 49 +++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 20 deletions(-)
diff -puN arch/x86/mm/init_64.c~x86-64-fall-back-to-regular-page-vmemmap-on-allocation-failure arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~x86-64-fall-back-to-regular-page-vmemmap-on-allocation-failure
+++ a/arch/x86/mm/init_64.c
@@ -1285,11 +1285,14 @@ static int __meminit vmemmap_populate_hu
unsigned long end, int node)
{
unsigned long addr;
+ unsigned long next;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- for (addr = start; addr < end; addr += PMD_SIZE) {
+ for (addr = start; addr < end; addr = next) {
+ next = pmd_addr_end(addr, end);
+
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
@@ -1300,31 +1303,37 @@ static int __meminit vmemmap_populate_hu
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
- pte_t entry;
void *p;
p = vmemmap_alloc_block_buf(PMD_SIZE, node);
- if (!p)
- return -ENOMEM;
+ if (p) {
+ pte_t entry;
- entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
- PAGE_KERNEL_LARGE);
- set_pmd(pmd, __pmd(pte_val(entry)));
-
- /* check to see if we have contiguous blocks */
- if (p_end != p || node_start != node) {
- if (p_start)
- printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
- addr_start, addr_end-1, p_start, p_end-1, node_start);
- addr_start = addr;
- node_start = node;
- p_start = p;
+ entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
+ PAGE_KERNEL_LARGE);
+ set_pmd(pmd, __pmd(pte_val(entry)));
+
+ /* check to see if we have contiguous blocks */
+ if (p_end != p || node_start != node) {
+ if (p_start)
+ printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
+ addr_start, addr_end-1, p_start, p_end-1, node_start);
+ addr_start = addr;
+ node_start = node;
+ p_start = p;
+ }
+
+ addr_end = addr + PMD_SIZE;
+ p_end = p + PMD_SIZE;
+ continue;
}
-
- addr_end = addr + PMD_SIZE;
- p_end = p + PMD_SIZE;
- } else
+ } else if (pmd_large(*pmd)) {
vmemmap_verify((pte_t *)pmd, node, addr, next);
+ continue;
+ }
+ pr_warn_once("vmemmap: falling back to regular page backing\n");
+ if (vmemmap_populate_basepages(addr, next, node))
+ return -ENOMEM;
}
return 0;
}
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
memcg-keep-prevs-css-alive-for-the-whole-mem_cgroup_iter.patch
memcg-rework-mem_cgroup_iter-to-use-cgroup-iterators.patch
memcg-relax-memcg-iter-caching.patch
memcg-simplify-mem_cgroup_iter.patch
memcg-further-simplify-mem_cgroup_iter.patch
cgroup-remove-css_get_next.patch
memcg-do-not-check-for-do_swap_account-in-mem_cgroup_readwritereset.patch
mm-try-harder-to-allocate-vmemmap-blocks.patch
sparse-vmemmap-specify-vmemmap-population-range-in-bytes.patch
x86-64-remove-dead-debugging-code-for-pse-setups.patch
x86-64-use-vmemmap_populate_basepages-for-pse-setups.patch
x86-64-fall-back-to-regular-page-vmemmap-on-allocation-failure.patch
mm-memmap_init_zone-performance-improvement.patch
memcg-debugging-facility-to-access-dangling-memcgs.patch
ipc-refactor-msg-list-search-into-separate-function-fix.patch
debugging-keep-track-of-page-owners-fix-2-fix-fix-fix.patch
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