Skip to content

Commit

Permalink
mm/swap: reduce indentation level
Browse files Browse the repository at this point in the history 
Patch series "mm/swap: remove boilerplate".


This patch (of 5):

Use folio_activate() as an example:

Before this series
------------------
    if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
      struct folio_batch *fbatch;

      folio_get(folio);
      if (!folio_test_clear_lru(folio)) {
        folio_put(folio);
        return;
      }

      local_lock(&cpu_fbatches.lock);
      fbatch = this_cpu_ptr(&cpu_fbatches.activate);
      folio_batch_add_and_move(fbatch, folio, folio_activate_fn);
      local_unlock(&cpu_fbatches.lock);
    }
  }

After this series
-----------------
  void folio_activate(struct folio *folio)
  {
    if (folio_test_active(folio) || folio_test_unevictable(folio))
      return;
  
    folio_batch_add_and_move(folio, lru_activate, true);
  }

And this is applied to all 6 folio_batch handlers in mm/swap.c.

bloat-o-meter
-------------
  add/remove: 12/13 grow/shrink: 3/2 up/down: 4653/-4721 (-68)
  ...
  Total: Before=28083019, After=28082951, chg -0.00%


This patch (of 5):

Reduce indentation level by returning directly when there is no cleanup
needed, i.e.,

  if (condition) {    |    if (condition) {
    do_this();        |      do_this();
    return;           |      return;
  } else {            |    }
    do_that();        |
  }                   |    do_that();

and

  if (condition) {    |    if (!condition)
    do_this();        |      return;
    do_that();        |
  }                   |    do_this();
  return;             |    do_that();

Presumably the old style became repetitive as the result of copy and
paste.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
  • Loading branch information
@yuzhaogoogle @akpm00
yuzhaogoogle authored and akpm00 committed Sep 2, 2024
1 parent ac59a1f commit b03484c
Showing 1 changed file with 109 additions and 100 deletions.
209 changes: 109 additions & 100 deletions mm/swap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -117,7 +117,9 @@ void __folio_put(struct folio *folio)
if (unlikely(folio_is_zone_device(folio))) {
free_zone_device_folio(folio);
return;
} else if (folio_test_hugetlb(folio)) {
}

if (folio_test_hugetlb(folio)) {
free_huge_folio(folio);
return;
}
Expand Down Expand Up @@ -228,17 +230,19 @@ static void folio_batch_add_and_move(struct folio_batch *fbatch,
if (folio_batch_add(fbatch, folio) && !folio_test_large(folio) &&
!lru_cache_disabled())
return;

folio_batch_move_lru(fbatch, move_fn);
}

static void lru_move_tail_fn(struct lruvec *lruvec, struct folio *folio)
{
if (!folio_test_unevictable(folio)) {
lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
lruvec_add_folio_tail(lruvec, folio);
__count_vm_events(PGROTATED, folio_nr_pages(folio));
}
if (folio_test_unevictable(folio))
return;

lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
lruvec_add_folio_tail(lruvec, folio);
__count_vm_events(PGROTATED, folio_nr_pages(folio));
}

/*
Expand All @@ -250,22 +254,23 @@ static void lru_move_tail_fn(struct lruvec *lruvec, struct folio *folio)
*/
void folio_rotate_reclaimable(struct folio *folio)
{
if (!folio_test_locked(folio) && !folio_test_dirty(folio) &&
!folio_test_unevictable(folio)) {
struct folio_batch *fbatch;
unsigned long flags;
struct folio_batch *fbatch;
unsigned long flags;

folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}
if (folio_test_locked(folio) || folio_test_dirty(folio) ||
folio_test_unevictable(folio))
return;

local_lock_irqsave(&lru_rotate.lock, flags);
fbatch = this_cpu_ptr(&lru_rotate.fbatch);
folio_batch_add_and_move(fbatch, folio, lru_move_tail_fn);
local_unlock_irqrestore(&lru_rotate.lock, flags);
folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}

local_lock_irqsave(&lru_rotate.lock, flags);
fbatch = this_cpu_ptr(&lru_rotate.fbatch);
folio_batch_add_and_move(fbatch, folio, lru_move_tail_fn);
local_unlock_irqrestore(&lru_rotate.lock, flags);
}

void lru_note_cost(struct lruvec *lruvec, bool file,
Expand Down Expand Up @@ -328,18 +333,19 @@ void lru_note_cost_refault(struct folio *folio)

static void folio_activate_fn(struct lruvec *lruvec, struct folio *folio)
{
if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
long nr_pages = folio_nr_pages(folio);
long nr_pages = folio_nr_pages(folio);

lruvec_del_folio(lruvec, folio);
folio_set_active(folio);
lruvec_add_folio(lruvec, folio);
trace_mm_lru_activate(folio);
if (folio_test_active(folio) || folio_test_unevictable(folio))
return;

__count_vm_events(PGACTIVATE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE,
nr_pages);
}

lruvec_del_folio(lruvec, folio);
folio_set_active(folio);
lruvec_add_folio(lruvec, folio);
trace_mm_lru_activate(folio);

__count_vm_events(PGACTIVATE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGACTIVATE, nr_pages);
}

#ifdef CONFIG_SMP
Expand All @@ -353,20 +359,21 @@ static void folio_activate_drain(int cpu)

void folio_activate(struct folio *folio)
{
if (!folio_test_active(folio) && !folio_test_unevictable(folio)) {
struct folio_batch *fbatch;
struct folio_batch *fbatch;

folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}
if (folio_test_active(folio) || folio_test_unevictable(folio))
return;

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.activate);
folio_batch_add_and_move(fbatch, folio, folio_activate_fn);
local_unlock(&cpu_fbatches.lock);
folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.activate);
folio_batch_add_and_move(fbatch, folio, folio_activate_fn);
local_unlock(&cpu_fbatches.lock);
}

#else
Expand All @@ -378,12 +385,13 @@ void folio_activate(struct folio *folio)
{
struct lruvec *lruvec;

if (folio_test_clear_lru(folio)) {
lruvec = folio_lruvec_lock_irq(folio);
folio_activate_fn(lruvec, folio);
unlock_page_lruvec_irq(lruvec);
folio_set_lru(folio);
}
if (!folio_test_clear_lru(folio))
return;

lruvec = folio_lruvec_lock_irq(folio);
folio_activate_fn(lruvec, folio);
unlock_page_lruvec_irq(lruvec);
folio_set_lru(folio);
}
#endif

Expand Down Expand Up @@ -610,41 +618,41 @@ static void lru_deactivate_file_fn(struct lruvec *lruvec, struct folio *folio)

static void lru_deactivate_fn(struct lruvec *lruvec, struct folio *folio)
{
if (!folio_test_unevictable(folio) && (folio_test_active(folio) || lru_gen_enabled())) {
long nr_pages = folio_nr_pages(folio);
long nr_pages = folio_nr_pages(folio);

lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
folio_clear_referenced(folio);
lruvec_add_folio(lruvec, folio);
if (folio_test_unevictable(folio) || !(folio_test_active(folio) || lru_gen_enabled()))
return;

__count_vm_events(PGDEACTIVATE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE,
nr_pages);
}
lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
folio_clear_referenced(folio);
lruvec_add_folio(lruvec, folio);

__count_vm_events(PGDEACTIVATE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_pages);
}

static void lru_lazyfree_fn(struct lruvec *lruvec, struct folio *folio)
{
if (folio_test_anon(folio) && folio_test_swapbacked(folio) &&
!folio_test_swapcache(folio) && !folio_test_unevictable(folio)) {
long nr_pages = folio_nr_pages(folio);
long nr_pages = folio_nr_pages(folio);

lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
folio_clear_referenced(folio);
/*
* Lazyfree folios are clean anonymous folios. They have
* the swapbacked flag cleared, to distinguish them from normal
* anonymous folios
*/
folio_clear_swapbacked(folio);
lruvec_add_folio(lruvec, folio);
if (!folio_test_anon(folio) || !folio_test_swapbacked(folio) ||
folio_test_swapcache(folio) || folio_test_unevictable(folio))
return;

__count_vm_events(PGLAZYFREE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE,
nr_pages);
}
lruvec_del_folio(lruvec, folio);
folio_clear_active(folio);
folio_clear_referenced(folio);
/*
* Lazyfree folios are clean anonymous folios. They have
* the swapbacked flag cleared, to distinguish them from normal
* anonymous folios
*/
folio_clear_swapbacked(folio);
lruvec_add_folio(lruvec, folio);

__count_vm_events(PGLAZYFREE, nr_pages);
__count_memcg_events(lruvec_memcg(lruvec), PGLAZYFREE, nr_pages);
}

/*
Expand Down Expand Up @@ -726,21 +734,21 @@ void deactivate_file_folio(struct folio *folio)
*/
void folio_deactivate(struct folio *folio)
{
if (!folio_test_unevictable(folio) && (folio_test_active(folio) ||
lru_gen_enabled())) {
struct folio_batch *fbatch;

folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}
struct folio_batch *fbatch;

if (folio_test_unevictable(folio) || !(folio_test_active(folio) || lru_gen_enabled()))
return;

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.lru_deactivate);
folio_batch_add_and_move(fbatch, folio, lru_deactivate_fn);
local_unlock(&cpu_fbatches.lock);
folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.lru_deactivate);
folio_batch_add_and_move(fbatch, folio, lru_deactivate_fn);
local_unlock(&cpu_fbatches.lock);
}

/**
Expand All @@ -752,21 +760,22 @@ void folio_deactivate(struct folio *folio)
*/
void folio_mark_lazyfree(struct folio *folio)
{
if (folio_test_anon(folio) && folio_test_swapbacked(folio) &&
!folio_test_swapcache(folio) && !folio_test_unevictable(folio)) {
struct folio_batch *fbatch;

folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}
struct folio_batch *fbatch;

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.lru_lazyfree);
folio_batch_add_and_move(fbatch, folio, lru_lazyfree_fn);
local_unlock(&cpu_fbatches.lock);
if (!folio_test_anon(folio) || !folio_test_swapbacked(folio) ||
folio_test_swapcache(folio) || folio_test_unevictable(folio))
return;

folio_get(folio);
if (!folio_test_clear_lru(folio)) {
folio_put(folio);
return;
}

local_lock(&cpu_fbatches.lock);
fbatch = this_cpu_ptr(&cpu_fbatches.lru_lazyfree);
folio_batch_add_and_move(fbatch, folio, lru_lazyfree_fn);
local_unlock(&cpu_fbatches.lock);
}

void lru_add_drain(void)
Expand Down

0 comments on commit b03484c

Please sign in to comment.