Re: [PATCH 8/8] Add VM counters for transparent hugepages
From: Andrea Arcangeli
Date: Thu Feb 24 2011 - 20:35:12 EST
On Fri, Feb 25, 2011 at 02:12:05AM +0100, Andi Kleen wrote:
> On Fri, Feb 25, 2011 at 01:51:55AM +0100, Andrea Arcangeli wrote:
> > On Tue, Feb 22, 2011 at 05:52:02PM -0800, Andi Kleen wrote:
> > > + "thp_direct_alloc",
> > > + "thp_daemon_alloc",
> > > + "thp_direct_fallback",
> > > + "thp_daemon_alloc_failed",
> >
> > I've been wondering if we should do s/daemon/khugepaged/ or
>
> Fine by me.
>
> > s/daemon/collapse/.
> >
> > And s/direct/fault/.
>
> Fine for me too.
So this would be it. (incremental with previous patch I sent that
adjusts the location of THP_SPLIT)
===
Subject: thp: make vmstat more accurate
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
s/direct/fault/g s/daemon/collapse/g
It's better to account even if memcg fails if the allocation succeeded so
it gives a bit more accurate ratios on the effectiveness of the VM in
creating hugepages. This adds coverage to the not NUMA case and it actually
uses THP_COLLAPSE_ALLOC. The thp_collapse_alloc is closely related to the
/sys/kernel/mm/transparent_hugepage/khugepaged/pages_collapsed but just like
for memcg this also accounts when the strict _allocation_ succeed but the
collapse can't go through after releasing the mmap_sem for a little
(pages_collapsed only accounts when the collapse really went through in
addition to the strict THP allocation).
Output under heavy swap load with khugepaged scan_sleep_millisecs=0
(and new kswapd compaction logic) follows.
$ vmstat 1
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
5 10 3390416 147772 2108 8476 0 42196 0 42196 6908 610 0 1 88 11
1 12 3493968 153624 2104 8968 0 103552 0 103552 2664 901 0 6 41 52
1 13 3598636 158336 2104 8404 0 104668 0 104668 778 431 0 5 60 34
1 12 3377120 130148 2104 7576 184 42120 184 42120 998 399 0 5 38 57
0 11 2419352 149360 2104 8844 232 19936 232 19936 9028 718 3 4 83 11
0 13 2488964 139476 2104 8036 0 76184 0 76184 3340 1133 0 1 89 11
$ grep thp /proc/vmstat
thp_fault_alloc 44725
thp_fault_fallback 364
thp_collapse_alloc 59
thp_collapse_alloc_failed 3
thp_split 14223
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
include/linux/vmstat.h | 8 ++++----
mm/huge_memory.c | 27 +++++++++++++++++++--------
mm/vmstat.c | 8 ++++----
3 files changed, 27 insertions(+), 16 deletions(-)
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -59,10 +59,10 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
UNEVICTABLE_MLOCKFREED,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- THP_DIRECT_ALLOC,
- THP_DAEMON_ALLOC,
- THP_DIRECT_FALLBACK,
- THP_DAEMON_ALLOC_FAILED,
+ THP_FAULT_ALLOC,
+ THP_FAULT_FALLBACK,
+ THP_COLLAPSE_ALLOC,
+ THP_COLLAPSE_ALLOC_FAILED,
THP_SPLIT,
#endif
NR_VM_EVENT_ITEMS
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -681,14 +681,14 @@ int do_huge_pmd_anonymous_page(struct mm
page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
vma, haddr, numa_node_id(), 0);
if (unlikely(!page)) {
- count_vm_event(THP_DIRECT_FALLBACK);
+ count_vm_event(THP_FAULT_FALLBACK);
goto out;
}
+ count_vm_event(THP_FAULT_ALLOC);
if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
put_page(page);
goto out;
}
- count_vm_event(THP_DIRECT_ALLOC);
return __do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page);
}
out:
@@ -911,12 +911,13 @@ int do_huge_pmd_wp_page(struct mm_struct
new_page = NULL;
if (unlikely(!new_page)) {
- count_vm_event(THP_DIRECT_FALLBACK);
+ count_vm_event(THP_FAULT_FALLBACK);
ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
pmd, orig_pmd, page, haddr);
put_page(page);
goto out;
}
+ count_vm_event(THP_FAULT_ALLOC);
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
put_page(new_page);
@@ -924,7 +925,7 @@ int do_huge_pmd_wp_page(struct mm_struct
ret |= VM_FAULT_OOM;
goto out;
}
- count_vm_event(THP_DIRECT_ALLOC);
+
copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);
__SetPageUptodate(new_page);
@@ -1784,10 +1785,11 @@ static void collapse_huge_page(struct mm
node, __GFP_OTHER_NODE);
if (unlikely(!new_page)) {
up_read(&mm->mmap_sem);
- count_vm_event(THP_DAEMON_ALLOC_FAILED);
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
*hpage = ERR_PTR(-ENOMEM);
return;
}
+ count_vm_event(THP_COLLAPSE_ALLOC);
#endif
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
up_read(&mm->mmap_sem);
@@ -2152,8 +2154,11 @@ static void khugepaged_do_scan(struct pa
#ifndef CONFIG_NUMA
if (!*hpage) {
*hpage = alloc_hugepage(khugepaged_defrag());
- if (unlikely(!*hpage))
+ if (unlikely(!*hpage)) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
break;
+ }
+ count_vm_event(THP_COLLAPSE_ALLOC);
}
#else
if (IS_ERR(*hpage))
@@ -2193,8 +2198,11 @@ static struct page *khugepaged_alloc_hug
do {
hpage = alloc_hugepage(khugepaged_defrag());
- if (!hpage)
+ if (!hpage) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
khugepaged_alloc_sleep();
+ } else
+ count_vm_event(THP_COLLAPSE_ALLOC);
} while (unlikely(!hpage) &&
likely(khugepaged_enabled()));
return hpage;
@@ -2211,8 +2219,11 @@ static void khugepaged_loop(void)
while (likely(khugepaged_enabled())) {
#ifndef CONFIG_NUMA
hpage = khugepaged_alloc_hugepage();
- if (unlikely(!hpage))
+ if (unlikely(!hpage)) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
break;
+ }
+ count_vm_event(THP_COLLAPSE_ALLOC);
#else
if (IS_ERR(hpage)) {
khugepaged_alloc_sleep();
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -948,10 +948,10 @@ static const char * const vmstat_text[]
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- "thp_direct_alloc",
- "thp_daemon_alloc",
- "thp_direct_fallback",
- "thp_daemon_alloc_failed",
+ "thp_fault_alloc",
+ "thp_fault_fallback",
+ "thp_collapse_alloc",
+ "thp_collapse_alloc_failure",
"thp_split",
#endif
};
--
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