The patch titled
Subject: mm/swap: pull the CPU conditional out of __lru_add_drain_all()
has been added to the -mm mm-unstable branch. Its filename is
mm-swap-pull-the-cpu-conditional-out-of-__lru_add_drain_all.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap-pull-the-cpu-conditional-out-of-__lru_add_drain_all.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/swap: pull the CPU conditional out of __lru_add_drain_all()
Date: Fri, 17 Jun 2022 18:50:08 +0100
The function is too long, so pull this complicated conditional out into
cpu_needs_drain(). This ends up shrinking the text by 14 bytes,
by allowing GCC to cache the result of calling per_cpu() instead of
relocating each lookup individually.
Link: https://lkml.kernel.org/r/20220617175020.717127-11-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swap.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--- a/mm/swap.c~mm-swap-pull-the-cpu-conditional-out-of-__lru_add_drain_all
+++ a/mm/swap.c
@@ -765,6 +765,21 @@ static void lru_add_drain_per_cpu(struct
lru_add_and_bh_lrus_drain();
}
+static bool cpu_needs_drain(unsigned int cpu)
+{
+ struct cpu_fbatches *fbatches = &per_cpu(cpu_fbatches, cpu);
+
+ /* Check these in order of likelihood that they're not zero */
+ return folio_batch_count(&fbatches->lru_add) ||
+ data_race(folio_batch_count(&per_cpu(lru_rotate.fbatch, cpu))) ||
+ folio_batch_count(&fbatches->lru_deactivate_file) ||
+ folio_batch_count(&fbatches->lru_deactivate) ||
+ folio_batch_count(&fbatches->lru_lazyfree) ||
+ folio_batch_count(&fbatches->activate) ||
+ need_mlock_page_drain(cpu) ||
+ has_bh_in_lru(cpu, NULL);
+}
+
/*
* Doesn't need any cpu hotplug locking because we do rely on per-cpu
* kworkers being shut down before our page_alloc_cpu_dead callback is
@@ -849,14 +864,7 @@ static inline void __lru_add_drain_all(b
for_each_online_cpu(cpu) {
struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
- if (folio_batch_count(&per_cpu(cpu_fbatches.lru_add, cpu)) ||
- data_race(folio_batch_count(&per_cpu(lru_rotate.fbatch, cpu))) ||
- folio_batch_count(&per_cpu(cpu_fbatches.lru_deactivate_file, cpu)) ||
- folio_batch_count(&per_cpu(cpu_fbatches.lru_deactivate, cpu)) ||
- folio_batch_count(&per_cpu(cpu_fbatches.lru_lazyfree, cpu)) ||
- folio_batch_count(&per_cpu(cpu_fbatches.activate, cpu)) ||
- need_mlock_page_drain(cpu) ||
- has_bh_in_lru(cpu, NULL)) {
+ if (cpu_needs_drain(cpu)) {
INIT_WORK(work, lru_add_drain_per_cpu);
queue_work_on(cpu, mm_percpu_wq, work);
__cpumask_set_cpu(cpu, &has_work);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-add-vma-iterator.patch
mmap-use-the-vma-iterator-in-count_vma_pages_range.patch
proc-remove-vma-rbtree-use-from-nommu.patch
arm64-remove-mmap-linked-list-from-vdso.patch
parisc-remove-mmap-linked-list-from-cache-handling.patch
powerpc-remove-mmap-linked-list-walks.patch
s390-remove-vma-linked-list-walks.patch
x86-remove-vma-linked-list-walks.patch
xtensa-remove-vma-linked-list-walks.patch
cxl-remove-vma-linked-list-walk.patch
optee-remove-vma-linked-list-walk.patch
um-remove-vma-linked-list-walk.patch
coredump-remove-vma-linked-list-walk.patch
exec-use-vma-iterator-instead-of-linked-list.patch
fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch
acct-use-vma-iterator-instead-of-linked-list.patch
perf-use-vma-iterator.patch
sched-use-maple-tree-iterator-to-walk-vmas.patch
fork-use-vma-iterator.patch
mm-khugepaged-stop-using-vma-linked-list.patch
mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch
i915-use-the-vma-iterator.patch
nommu-remove-uses-of-vma-linked-list.patch
mm-vmscan-convert-reclaim_clean_pages_from_list-to-folios.patch
mm-vmscan-convert-isolate_lru_pages-to-use-a-folio.patch
mm-vmscan-convert-move_pages_to_lru-to-use-a-folio.patch
mm-vmscan-convert-shrink_active_list-to-use-a-folio.patch
mm-vmscan-convert-reclaim_pages-to-use-a-folio.patch
mm-add-folios_put.patch
mm-swap-add-folio_batch_move_lru.patch
mm-swap-make-__pagevec_lru_add-static.patch
mm-swap-convert-lru_add-to-a-folio_batch.patch
mm-swap-convert-lru_deactivate_file-to-a-folio_batch.patch
mm-swap-convert-lru_deactivate-to-a-folio_batch.patch
mm-swap-convert-lru_lazyfree-to-a-folio_batch.patch
mm-swap-convert-activate_page-to-a-folio_batch.patch
mm-swap-rename-lru_pvecs-to-cpu_fbatches.patch
mm-swap-pull-the-cpu-conditional-out-of-__lru_add_drain_all.patch
mm-swap-optimise-lru_add_drain_cpu.patch
mm-swap-convert-try_to_free_swap-to-use-a-folio.patch
mm-swap-convert-release_pages-to-use-a-folio-internally.patch
mm-swap-convert-put_pages_list-to-use-folios.patch
mm-swap-convert-__put_page-to-__folio_put.patch
mm-swap-convert-__put_single_page-to-__folio_put_small.patch
mm-swap-convert-__put_compound_page-to-__folio_put_large.patch
mm-swap-convert-__page_cache_release-to-use-a-folio.patch
mm-convert-destroy_compound_page-to-destroy_large_folio.patch
mm-convert-page_swap_flags-to-folio_swap_flags.patch
mm-swap-convert-delete_from_swap_cache-to-take-a-folio.patch
mm-swap-convert-__delete_from_swap_cache-to-a-folio.patch
