* [PATCH] z3fold: avoid modifying HEADLESS page and minor cleanup
@ 2016-05-27 16:06 Vitaly Wool
2016-05-27 18:37 ` Dan Streetman
0 siblings, 1 reply; 2+ messages in thread
From: Vitaly Wool @ 2016-05-27 16:06 UTC (permalink / raw)
To: Linux-MM, linux-kernel; +Cc: Seth Jennings, Dan Streetman, Andrew Morton
This patch fixes erroneous z3fold header access in a HEADLESS page
in reclaim function, and changes one remaining direct
handle-to-buddy conversion to use the appropriate helper.
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
---
mm/z3fold.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 34917d5..8f9e89c 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -412,7 +412,7 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
/* HEADLESS page stored */
bud = HEADLESS;
} else {
- bud = (handle - zhdr->first_num) & BUDDY_MASK;
+ bud = handle_to_buddy(handle);
switch (bud) {
case FIRST:
@@ -572,15 +572,19 @@ next:
pool->pages_nr--;
spin_unlock(&pool->lock);
return 0;
- } else if (zhdr->first_chunks != 0 &&
- zhdr->last_chunks != 0 && zhdr->middle_chunks != 0) {
- /* Full, add to buddied list */
- list_add(&zhdr->buddy, &pool->buddied);
- } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
- z3fold_compact_page(zhdr);
- /* add to unbuddied list */
- freechunks = num_free_chunks(zhdr);
- list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
+ } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
+ if (zhdr->first_chunks != 0 &&
+ zhdr->last_chunks != 0 &&
+ zhdr->middle_chunks != 0) {
+ /* Full, add to buddied list */
+ list_add(&zhdr->buddy, &pool->buddied);
+ } else {
+ z3fold_compact_page(zhdr);
+ /* add to unbuddied list */
+ freechunks = num_free_chunks(zhdr);
+ list_add(&zhdr->buddy,
+ &pool->unbuddied[freechunks]);
+ }
}
/* add to beginning of LRU */
--
2.5.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] z3fold: avoid modifying HEADLESS page and minor cleanup
2016-05-27 16:06 [PATCH] z3fold: avoid modifying HEADLESS page and minor cleanup Vitaly Wool
@ 2016-05-27 18:37 ` Dan Streetman
0 siblings, 0 replies; 2+ messages in thread
From: Dan Streetman @ 2016-05-27 18:37 UTC (permalink / raw)
To: Vitaly Wool; +Cc: Linux-MM, linux-kernel, Seth Jennings, Andrew Morton
On Fri, May 27, 2016 at 12:06 PM, Vitaly Wool <vitalywool@gmail.com> wrote:
> This patch fixes erroneous z3fold header access in a HEADLESS page
> in reclaim function, and changes one remaining direct
> handle-to-buddy conversion to use the appropriate helper.
>
> Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reviewed-by: Dan Streetman <ddstreet@ieee.org>
> ---
> mm/z3fold.c | 24 ++++++++++++++----------
> 1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index 34917d5..8f9e89c 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -412,7 +412,7 @@ static void z3fold_free(struct z3fold_pool *pool,
> unsigned long handle)
> /* HEADLESS page stored */
> bud = HEADLESS;
> } else {
> - bud = (handle - zhdr->first_num) & BUDDY_MASK;
> + bud = handle_to_buddy(handle);
> switch (bud) {
> case FIRST:
> @@ -572,15 +572,19 @@ next:
> pool->pages_nr--;
> spin_unlock(&pool->lock);
> return 0;
> - } else if (zhdr->first_chunks != 0 &&
> - zhdr->last_chunks != 0 && zhdr->middle_chunks !=
> 0) {
> - /* Full, add to buddied list */
> - list_add(&zhdr->buddy, &pool->buddied);
> - } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
> - z3fold_compact_page(zhdr);
> - /* add to unbuddied list */
> - freechunks = num_free_chunks(zhdr);
> - list_add(&zhdr->buddy,
> &pool->unbuddied[freechunks]);
> + } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
> + if (zhdr->first_chunks != 0 &&
> + zhdr->last_chunks != 0 &&
> + zhdr->middle_chunks != 0) {
> + /* Full, add to buddied list */
> + list_add(&zhdr->buddy, &pool->buddied);
> + } else {
> + z3fold_compact_page(zhdr);
> + /* add to unbuddied list */
> + freechunks = num_free_chunks(zhdr);
> + list_add(&zhdr->buddy,
> + &pool->unbuddied[freechunks]);
> + }
> }
> /* add to beginning of LRU */
> --
> 2.5.0
>
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