The patch titled
thp: freeze khugepaged and ksmd
has been added to the -mm tree. Its filename is
thp-freeze-khugepaged-and-ksmd.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: thp: freeze khugepaged and ksmd
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
It's unclear why schedule friendly kernel threads can't be taken away by
the CPU through the scheduler itself. It's safer to stop them as they can
trigger memory allocation, if kswapd also freezes itself to avoid
generating I/O they have too.
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 14 ++++++++++++--
mm/ksm.c | 8 ++++++--
2 files changed, 18 insertions(+), 4 deletions(-)
diff -puN mm/huge_memory.c~thp-freeze-khugepaged-and-ksmd mm/huge_memory.c
--- a/mm/huge_memory.c~thp-freeze-khugepaged-and-ksmd
+++ a/mm/huge_memory.c
@@ -15,6 +15,7 @@
#include <linux/mm_inline.h>
#include <linux/kthread.h>
#include <linux/khugepaged.h>
+#include <linux/freezer.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
@@ -2085,6 +2086,9 @@ static void khugepaged_do_scan(struct pa
break;
#endif
+ if (unlikely(kthread_should_stop() || freezing(current)))
+ break;
+
spin_lock(&khugepaged_mm_lock);
if (!khugepaged_scan.mm_slot)
pass_through_head++;
@@ -2147,6 +2151,9 @@ static void khugepaged_loop(void)
if (hpage)
put_page(hpage);
#endif
+ try_to_freeze();
+ if (unlikely(kthread_should_stop()))
+ break;
if (khugepaged_has_work()) {
DEFINE_WAIT(wait);
if (!khugepaged_scan_sleep_millisecs)
@@ -2157,8 +2164,8 @@ static void khugepaged_loop(void)
khugepaged_scan_sleep_millisecs));
remove_wait_queue(&khugepaged_wait, &wait);
} else if (khugepaged_enabled())
- wait_event_interruptible(khugepaged_wait,
- khugepaged_wait_event());
+ wait_event_freezable(khugepaged_wait,
+ khugepaged_wait_event());
}
}
@@ -2166,6 +2173,7 @@ static int khugepaged(void *none)
{
struct mm_slot *mm_slot;
+ set_freezable();
set_user_nice(current, 19);
/* serialize with start_khugepaged() */
@@ -2180,6 +2188,8 @@ static int khugepaged(void *none)
mutex_lock(&khugepaged_mutex);
if (!khugepaged_enabled())
break;
+ if (unlikely(kthread_should_stop()))
+ break;
}
spin_lock(&khugepaged_mm_lock);
diff -puN mm/ksm.c~thp-freeze-khugepaged-and-ksmd mm/ksm.c
--- a/mm/ksm.c~thp-freeze-khugepaged-and-ksmd
+++ a/mm/ksm.c
@@ -34,6 +34,7 @@
#include <linux/swap.h>
#include <linux/ksm.h>
#include <linux/hash.h>
+#include <linux/freezer.h>
#include <asm/tlbflush.h>
#include "internal.h"
@@ -1365,7 +1366,7 @@ static void ksm_do_scan(unsigned int sca
struct rmap_item *rmap_item;
struct page *uninitialized_var(page);
- while (scan_npages--) {
+ while (scan_npages-- && likely(!freezing(current))) {
cond_resched();
rmap_item = scan_get_next_rmap_item(&page);
if (!rmap_item)
@@ -1383,6 +1384,7 @@ static int ksmd_should_run(void)
static int ksm_scan_thread(void *nothing)
{
+ set_freezable();
set_user_nice(current, 5);
while (!kthread_should_stop()) {
@@ -1391,11 +1393,13 @@ static int ksm_scan_thread(void *nothing
ksm_do_scan(ksm_thread_pages_to_scan);
mutex_unlock(&ksm_thread_mutex);
+ try_to_freeze();
+
if (ksmd_should_run()) {
schedule_timeout_interruptible(
msecs_to_jiffies(ksm_thread_sleep_millisecs));
} else {
- wait_event_interruptible(ksm_thread_wait,
+ wait_event_freezable(ksm_thread_wait,
ksmd_should_run() || kthread_should_stop());
}
}
_
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
mm-compaction-add-trace-events-for-memory-compaction-activity.patch
mm-vmscan-convert-lumpy_mode-into-a-bitmask.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim.patch
mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-fix.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path.patch
mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path-fix.patch
mm-migration-cleanup-migrate_pages-api-by-matching-types-for-offlining-and-sync.patch
mm-compaction-perform-a-faster-migration-scan-when-migrating-asynchronously.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode.patch
mm-vmscan-rename-lumpy_mode-to-reclaim_mode-fix.patch
thp-ksm-free-swap-when-swapcache-page-is-replaced.patch
thp-fix-bad_page-to-show-the-real-reason-the-page-is-bad.patch
thp-transparent-hugepage-support-documentation.patch
thp-mm-define-madv_hugepage.patch
thp-compound_lock.patch
thp-alter-compound-get_page-put_page.patch
thp-put_page-recheck-pagehead-after-releasing-the-compound_lock.patch
thp-update-futex-compound-knowledge.patch
thp-clear-compound-mapping.patch
thp-add-native_set_pmd_at.patch
thp-add-pmd-paravirt-ops.patch
thp-no-paravirt-version-of-pmd-ops.patch
thp-export-maybe_mkwrite.patch
thp-comment-reminder-in-destroy_compound_page.patch
thp-config_transparent_hugepage.patch
thp-special-pmd_trans_-functions.patch
thp-add-pmd-mangling-generic-functions.patch
thp-add-pmd-mangling-functions-to-x86.patch
thp-bail-out-gup_fast-on-splitting-pmd.patch
thp-pte-alloc-trans-splitting.patch
thp-add-pmd-mmu_notifier-helpers.patch
thp-clear-page-compound.patch
thp-add-pmd_huge_pte-to-mm_struct.patch
thp-split_huge_page_mm-vma.patch
thp-split_huge_page-paging.patch
thp-clear_copy_huge_page.patch
thp-_gfp_no_kswapd.patch
thp-dont-alloc-harder-for-gfp-nomemalloc-even-if-nowait.patch
thp-transparent-hugepage-core.patch
thp-split_huge_page-anon_vma-ordering-dependency.patch
thp-verify-pmd_trans_huge-isnt-leaking.patch
thp-madvisemadv_hugepage.patch
thp-add-pagetranscompound.patch
thp-pmd_trans_huge-migrate-bugcheck.patch
thp-memcg-compound.patch
thp-transhuge-memcg-commit-tail-pages-at-charge.patch
thp-memcg-huge-memory.patch
thp-transparent-hugepage-vmstat.patch
thp-khugepaged.patch
thp-khugepaged-vma-merge.patch
thp-skip-transhuge-pages-in-ksm-for-now.patch
thp-remove-pg_buddy.patch
thp-add-x86-32bit-support.patch
thp-mincore-transparent-hugepage-support.patch
thp-add-pmd_modify.patch
thp-mprotect-pass-vma-down-to-page-table-walkers.patch
thp-mprotect-transparent-huge-page-support.patch
thp-set-recommended-min-free-kbytes.patch
thp-enable-direct-defrag.patch
thp-add-numa-awareness-to-hugepage-allocations.patch
thp-allocate-memory-in-khugepaged-outside-of-mmap_sem-write-mode.patch
thp-transparent-hugepage-config-choice.patch
thp-select-config_compaction-if-transparent_hugepage-enabled.patch
thp-transhuge-isolate_migratepages.patch
thp-avoid-breaking-huge-pmd-invariants-in-case-of-vma_adjust-failures.patch
thp-dont-allow-transparent-hugepage-support-without-pse.patch
thp-mmu_notifier_test_young.patch
thp-freeze-khugepaged-and-ksmd.patch
thp-use-compaction-in-kswapd-for-gfp_atomic-order-0.patch
thp-use-compaction-for-all-allocation-orders.patch
thp-disable-transparent-hugepages-by-default-on-small-systems.patch
thp-fix-anon-memory-statistics-with-transparent-hugepages.patch
thp-scale-nr_rotated-to-balance-memory-pressure.patch
thp-transparent-hugepage-sysfs-meminfo.patch
thp-add-debug-checks-for-mapcount-related-invariants.patch
thp-fix-memory-failure-hugetlbfs-vs-thp-collision.patch
thp-compound_trans_order.patch
thp-mm-define-madv_nohugepage.patch
thp-madvisemadv_nohugepage.patch
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