Allocate post-processing target in place_pp_slot(). This
simplifies scan_slots_for_writeback() and scan_slots_for_recompress()
loops because we don't need to track pps pointer state anymore.
Previously we have to explicitly NULL the point if it has been added
to a post-processing bucket or re-use previously allocated pointer
otherwise and make sure we don't leak the memory in the end.
We are also fine doing GFP_NOIO allocation, as post-processing can
be called under memory pressure so we better pick as many slots as
we can as soon as we can and start post-processing them, possibly
saving the memory. Allocation failure there is not fatal, we will
post-process whatever we put into the buckets on previous
iterations.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 50 +++++++++++++++--------------------
1 file changed, 22 insertions(+), 28 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6755ca90f737..7ad89df9a304 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -295,15 +295,24 @@ static void release_pp_ctl(struct zram *zram, struct zram_pp_ctl *ctl)
kfree(ctl);
}
-static void place_pp_slot(struct zram *zram, struct zram_pp_ctl *ctl,
- struct zram_pp_slot *pps)
+static bool place_pp_slot(struct zram *zram, struct zram_pp_ctl *ctl,
+ u32 index)
{
- u32 idx;
+ struct zram_pp_slot *pps;
+ u32 bid;
+
+ pps = kmalloc(sizeof(*pps), GFP_NOIO | __GFP_NOWARN);
+ if (!pps)
+ return false;
- idx = zram_get_obj_size(zram, pps->index) / PP_BUCKET_SIZE_RANGE;
- list_add(&pps->entry, &ctl->pp_buckets[idx]);
+ INIT_LIST_HEAD(&pps->entry);
+ pps->index = index;
+
+ bid = zram_get_obj_size(zram, pps->index) / PP_BUCKET_SIZE_RANGE;
+ list_add(&pps->entry, &ctl->pp_buckets[bid]);
zram_set_flag(zram, pps->index, ZRAM_PP_SLOT);
+ return true;
}
static struct zram_pp_slot *select_pp_slot(struct zram_pp_ctl *ctl)
@@ -737,15 +746,8 @@ static int scan_slots_for_writeback(struct zram *zram, u32 mode,
unsigned long index,
struct zram_pp_ctl *ctl)
{
- struct zram_pp_slot *pps = NULL;
-
for (; nr_pages != 0; index++, nr_pages--) {
- if (!pps)
- pps = kmalloc(sizeof(*pps), GFP_KERNEL);
- if (!pps)
- return -ENOMEM;
-
- INIT_LIST_HEAD(&pps->entry);
+ bool ok = true;
zram_slot_lock(zram, index);
if (!zram_allocated(zram, index))
@@ -765,14 +767,13 @@ static int scan_slots_for_writeback(struct zram *zram, u32 mode,
!zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE))
goto next;
- pps->index = index;
- place_pp_slot(zram, ctl, pps);
- pps = NULL;
+ ok = place_pp_slot(zram, ctl, index);
next:
zram_slot_unlock(zram, index);
+ if (!ok)
+ break;
}
- kfree(pps);
return 0;
}
@@ -1827,16 +1828,10 @@ static int scan_slots_for_recompress(struct zram *zram, u32 mode, u32 prio_max,
struct zram_pp_ctl *ctl)
{
unsigned long nr_pages = zram->disksize >> PAGE_SHIFT;
- struct zram_pp_slot *pps = NULL;
unsigned long index;
for (index = 0; index < nr_pages; index++) {
- if (!pps)
- pps = kmalloc(sizeof(*pps), GFP_KERNEL);
- if (!pps)
- return -ENOMEM;
-
- INIT_LIST_HEAD(&pps->entry);
+ bool ok = true;
zram_slot_lock(zram, index);
if (!zram_allocated(zram, index))
@@ -1859,14 +1854,13 @@ static int scan_slots_for_recompress(struct zram *zram, u32 mode, u32 prio_max,
if (zram_get_priority(zram, index) + 1 >= prio_max)
goto next;
- pps->index = index;
- place_pp_slot(zram, ctl, pps);
- pps = NULL;
+ ok = place_pp_slot(zram, ctl, index);
next:
zram_slot_unlock(zram, index);
+ if (!ok)
+ break;
}
- kfree(pps);
return 0;
}
--
2.48.1.658.g4767266eb4-goog
