[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20140509033304.GA2274@cerebellum.variantweb.net>
Date: Thu, 8 May 2014 22:33:04 -0500
From: Seth Jennings <sjennings@...iantweb.net>
To: Dan Streetman <ddstreet@...e.org>
Cc: Minchan Kim <minchan@...nel.org>,
Weijie Yang <weijie.yang@...sung.com>,
Nitin Gupta <ngupta@...are.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Bob Liu <bob.liu@...cle.com>, Hugh Dickins <hughd@...gle.com>,
Mel Gorman <mgorman@...e.de>, Rik van Riel <riel@...hat.com>,
Johannes Weiner <hannes@...xchg.org>,
Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
Linux-MM <linux-mm@...ck.org>,
linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCHv2 1/4] mm/zbud: zbud_alloc() minor param change
On Wed, May 07, 2014 at 05:51:33PM -0400, Dan Streetman wrote:
> Change zbud to store gfp_t flags passed at pool creation to use for
> each alloc; this allows the api to be closer to the existing zsmalloc
> interface, and the only current zbud user (zswap) uses the same gfp
> flags for all allocs. Update zswap to use changed interface.
>
Acked-by: Seth Jennings <sjennings@...iantweb.net>
> Signed-off-by: Dan Streetman <ddstreet@...e.org>
> Cc: Seth Jennings <sjennings@...iantweb.net>
> Cc: Weijie Yang <weijie.yang@...sung.com>
> ---
>
> Changes since v1 https://lkml.org/lkml/2014/4/19/98
> -context changes only; zbud_alloc parameter type changed since
> last patch
>
> include/linux/zbud.h | 2 +-
> mm/zbud.c | 27 +++++++++++++++------------
> mm/zswap.c | 6 +++---
> 3 files changed, 19 insertions(+), 16 deletions(-)
>
> diff --git a/include/linux/zbud.h b/include/linux/zbud.h
> index 13af0d4..0b2534e 100644
> --- a/include/linux/zbud.h
> +++ b/include/linux/zbud.h
> @@ -11,7 +11,7 @@ struct zbud_ops {
>
> struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops);
> void zbud_destroy_pool(struct zbud_pool *pool);
> -int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
> +int zbud_alloc(struct zbud_pool *pool, unsigned int size,
> unsigned long *handle);
> void zbud_free(struct zbud_pool *pool, unsigned long handle);
> int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries);
> diff --git a/mm/zbud.c b/mm/zbud.c
> index 01df13a..847c01c 100644
> --- a/mm/zbud.c
> +++ b/mm/zbud.c
> @@ -94,6 +94,7 @@ struct zbud_pool {
> struct list_head lru;
> u64 pages_nr;
> struct zbud_ops *ops;
> + gfp_t gfp;
> };
>
> /*
> @@ -193,9 +194,12 @@ static int num_free_chunks(struct zbud_header *zhdr)
> *****************/
> /**
> * zbud_create_pool() - create a new zbud pool
> - * @gfp: gfp flags when allocating the zbud pool structure
> + * @gfp: gfp flags when growing the pool
> * @ops: user-defined operations for the zbud pool
> *
> + * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
> + * as zbud pool pages.
> + *
> * Return: pointer to the new zbud pool or NULL if the metadata allocation
> * failed.
> */
> @@ -204,7 +208,9 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops)
> struct zbud_pool *pool;
> int i;
>
> - pool = kmalloc(sizeof(struct zbud_pool), gfp);
> + if (gfp & __GFP_HIGHMEM)
> + return NULL;
> + pool = kmalloc(sizeof(struct zbud_pool), GFP_KERNEL);
> if (!pool)
> return NULL;
> spin_lock_init(&pool->lock);
> @@ -214,6 +220,7 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, struct zbud_ops *ops)
> INIT_LIST_HEAD(&pool->lru);
> pool->pages_nr = 0;
> pool->ops = ops;
> + pool->gfp = gfp;
> return pool;
> }
>
> @@ -232,7 +239,6 @@ void zbud_destroy_pool(struct zbud_pool *pool)
> * zbud_alloc() - allocates a region of a given size
> * @pool: zbud pool from which to allocate
> * @size: size in bytes of the desired allocation
> - * @gfp: gfp flags used if the pool needs to grow
> * @handle: handle of the new allocation
> *
> * This function will attempt to find a free region in the pool large enough to
> @@ -240,14 +246,11 @@ void zbud_destroy_pool(struct zbud_pool *pool)
> * performed first. If no suitable free region is found, then a new page is
> * allocated and added to the pool to satisfy the request.
> *
> - * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
> - * as zbud pool pages.
> - *
> - * Return: 0 if success and handle is set, otherwise -EINVAL if the size or
> - * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
> - * a new page.
> + * Return: 0 if success and @handle is set, -ENOSPC if the @size is too large,
> + * -EINVAL if the @size is 0, or -ENOMEM if the pool was unable to
> + * allocate a new page.
> */
> -int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
> +int zbud_alloc(struct zbud_pool *pool, unsigned int size,
> unsigned long *handle)
> {
> int chunks, i, freechunks;
> @@ -255,7 +258,7 @@ int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
> enum buddy bud;
> struct page *page;
>
> - if (!size || (gfp & __GFP_HIGHMEM))
> + if (!size)
> return -EINVAL;
> if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE)
> return -ENOSPC;
> @@ -279,7 +282,7 @@ int zbud_alloc(struct zbud_pool *pool, unsigned int size, gfp_t gfp,
>
> /* Couldn't find unbuddied zbud page, create new one */
> spin_unlock(&pool->lock);
> - page = alloc_page(gfp);
> + page = alloc_page(pool->gfp);
> if (!page)
> return -ENOMEM;
> spin_lock(&pool->lock);
> diff --git a/mm/zswap.c b/mm/zswap.c
> index aeaef0f..1cc6770 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -679,8 +679,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
>
> /* store */
> len = dlen + sizeof(struct zswap_header);
> - ret = zbud_alloc(zswap_pool, len, __GFP_NORETRY | __GFP_NOWARN,
> - &handle);
> + ret = zbud_alloc(zswap_pool, len, &handle);
> if (ret == -ENOSPC) {
> zswap_reject_compress_poor++;
> goto freepage;
> @@ -900,7 +899,8 @@ static int __init init_zswap(void)
>
> pr_info("loading zswap\n");
>
> - zswap_pool = zbud_create_pool(GFP_KERNEL, &zswap_zbud_ops);
> + zswap_pool = zbud_create_pool(__GFP_NORETRY | __GFP_NOWARN,
> + &zswap_zbud_ops);
> if (!zswap_pool) {
> pr_err("zbud pool creation failed\n");
> goto error;
> --
> 1.8.3.1
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists