The patch titled
Subject: thp: merge page pre-alloc in khugepaged_loop into khugepaged_do_scan
has been added to the -mm tree. Its filename is
thp-merge-page-pre-alloc-in-khugepaged_loop-into-khugepaged_do_scan.patch
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------------------------------------------------------
From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
Subject: thp: merge page pre-alloc in khugepaged_loop into khugepaged_do_scan
There are two pre-alloc operations in these two function, the different is:
- it allows to sleep if page alloc fail in khugepaged_loop
- it exits immediately if page alloc fail in khugepaged_do_scan
Actually, in khugepaged_do_scan, we can allow the pre-alloc to sleep on
the first failure, then the operation in khugepaged_loop can be removed
Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 97 ++++++++++++++++++++-------------------------
1 file changed, 45 insertions(+), 52 deletions(-)
diff -puN mm/huge_memory.c~thp-merge-page-pre-alloc-in-khugepaged_loop-into-khugepaged_do_scan mm/huge_memory.c
--- a/mm/huge_memory.c~thp-merge-page-pre-alloc-in-khugepaged_loop-into-khugepaged_do_scan
+++ a/mm/huge_memory.c
@@ -2223,10 +2223,40 @@ static int khugepaged_wait_event(void)
kthread_should_stop();
}
-static void khugepaged_do_scan(struct page **hpage)
+static void khugepaged_alloc_sleep(void)
{
+ wait_event_freezable_timeout(khugepaged_wait, false,
+ msecs_to_jiffies(khugepaged_alloc_sleep_millisecs));
+}
+
+#ifndef CONFIG_NUMA
+static struct page *khugepaged_alloc_hugepage(bool *wait)
+{
+ struct page *hpage;
+
+ do {
+ hpage = alloc_hugepage(khugepaged_defrag());
+ if (!hpage) {
+ count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ if (!*wait)
+ return NULL;
+
+ *wait = false;
+ khugepaged_alloc_sleep();
+ } else
+ count_vm_event(THP_COLLAPSE_ALLOC);
+ } while (unlikely(!hpage) && likely(khugepaged_enabled()));
+
+ return hpage;
+}
+#endif
+
+static void khugepaged_do_scan(void)
+{
+ struct page *hpage = NULL;
unsigned int progress = 0, pass_through_head = 0;
unsigned int pages = khugepaged_pages_to_scan;
+ bool wait = true;
barrier(); /* write khugepaged_pages_to_scan to local stack */
@@ -2234,17 +2264,18 @@ static void khugepaged_do_scan(struct pa
cond_resched();
#ifndef CONFIG_NUMA
- if (!*hpage) {
- *hpage = alloc_hugepage(khugepaged_defrag());
- if (unlikely(!*hpage)) {
- count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+ if (!hpage)
+ hpage = khugepaged_alloc_hugepage(&wait);
+
+ if (unlikely(!hpage))
+ break;
+#else
+ if (IS_ERR(hpage)) {
+ if (!wait)
break;
- }
- count_vm_event(THP_COLLAPSE_ALLOC);
+ wait = false;
+ khugepaged_alloc_sleep();
}
-#else
- if (IS_ERR(*hpage))
- break;
#endif
if (unlikely(kthread_should_stop() || freezing(current)))
@@ -2256,37 +2287,16 @@ static void khugepaged_do_scan(struct pa
if (khugepaged_has_work() &&
pass_through_head < 2)
progress += khugepaged_scan_mm_slot(pages - progress,
- hpage);
+ &hpage);
else
progress = pages;
spin_unlock(&khugepaged_mm_lock);
}
-}
-static void khugepaged_alloc_sleep(void)
-{
- wait_event_freezable_timeout(khugepaged_wait, false,
- msecs_to_jiffies(khugepaged_alloc_sleep_millisecs));
+ if (!IS_ERR_OR_NULL(hpage))
+ put_page(hpage);
}
-#ifndef CONFIG_NUMA
-static struct page *khugepaged_alloc_hugepage(void)
-{
- struct page *hpage;
-
- do {
- hpage = alloc_hugepage(khugepaged_defrag());
- 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;
-}
-#endif
-
static void khugepaged_wait_work(void)
{
try_to_freeze();
@@ -2307,25 +2317,8 @@ static void khugepaged_wait_work(void)
static void khugepaged_loop(void)
{
- struct page *hpage = NULL;
-
while (likely(khugepaged_enabled())) {
-#ifndef CONFIG_NUMA
- hpage = khugepaged_alloc_hugepage();
- if (unlikely(!hpage))
- break;
-#else
- if (IS_ERR(hpage)) {
- khugepaged_alloc_sleep();
- hpage = NULL;
- }
-#endif
-
- khugepaged_do_scan(&hpage);
-
- if (!IS_ERR_OR_NULL(hpage))
- put_page(hpage);
-
+ khugepaged_do_scan();
khugepaged_wait_work();
}
}
_
Patches currently in -mm which might be from xiaoguangrong@xxxxxxxxxxxxxxxxxx are
linux-next.patch
thp-fix-the-count-of-thp_collapse_alloc.patch
thp-remove-unnecessary-check-in-start_khugepaged.patch
thp-move-khugepaged_mutex-out-of-khugepaged.patch
thp-remove-unnecessary-khugepaged_thread-check.patch
thp-remove-wake_up_interruptible-in-the-exit-path.patch
thp-remove-some-code-depend-on-config_numa.patch
thp-merge-page-pre-alloc-in-khugepaged_loop-into-khugepaged_do_scan.patch
thp-release-page-in-page-pre-alloc-path.patch
thp-introduce-khugepaged_prealloc_page-and-khugepaged_alloc_page.patch
thp-remove-khugepaged_loop.patch
thp-use-khugepaged_enabled-to-remove-duplicate-code.patch
thp-remove-unnecessary-set_recommended_min_free_kbytes.patch
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