Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752719AbaAUCbd (ORCPT ); Mon, 20 Jan 2014 21:31:33 -0500 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:60586 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750AbaAUCbZ (ORCPT ); Mon, 20 Jan 2014 21:31:25 -0500 X-AuditID: 9c93016f-b7b1aae000000f15-ac-52dddbfbc10e Date: Tue, 21 Jan 2014 11:32:33 +0900 From: Minchan Kim To: Cai Liu Cc: "'Andrew Morton'" , "'Seth Jennings'" , "'Bob Liu'" , "'Linux-MM'" , "'Linux-Kernel'" , liucai.lfn@gmail.com Subject: Re: [PATCH v2] mm/zswap: Check all pool pages instead of one pool pages Message-ID: <20140121023233.GI28712@bbox> References: <000701cf15b4$6822c740$386855c0$@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000701cf15b4$6822c740$386855c0$@samsung.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Cai, On Mon, Jan 20, 2014 at 03:50:18PM +0800, Cai Liu wrote: > zswap can support multiple swapfiles. So we need to check > all zbud pool pages in zswap. > > Version 2: > * add *total_zbud_pages* in zbud to record all the pages in pools > * move the updating of pool pages statistics to > alloc_zbud_page/free_zbud_page to hide the details > > Signed-off-by: Cai Liu > --- > include/linux/zbud.h | 2 +- > mm/zbud.c | 44 ++++++++++++++++++++++++++++++++------------ > mm/zswap.c | 4 ++-- > 3 files changed, 35 insertions(+), 15 deletions(-) > > diff --git a/include/linux/zbud.h b/include/linux/zbud.h > index 2571a5c..1dbc13e 100644 > --- a/include/linux/zbud.h > +++ b/include/linux/zbud.h > @@ -17,6 +17,6 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle); > int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries); > void *zbud_map(struct zbud_pool *pool, unsigned long handle); > void zbud_unmap(struct zbud_pool *pool, unsigned long handle); > -u64 zbud_get_pool_size(struct zbud_pool *pool); > +u64 zbud_get_pool_size(void); > > #endif /* _ZBUD_H_ */ > diff --git a/mm/zbud.c b/mm/zbud.c > index 9451361..711aaf4 100644 > --- a/mm/zbud.c > +++ b/mm/zbud.c > @@ -52,6 +52,13 @@ > #include > #include > > +/********************************* > +* statistics > +**********************************/ > + > +/* zbud pages in all pools */ > +static u64 total_zbud_pages; > + > /***************** > * Structures > *****************/ > @@ -142,10 +149,28 @@ static struct zbud_header *init_zbud_page(struct page *page) > return zhdr; > } > > +static struct page *alloc_zbud_page(struct zbud_pool *pool, gfp_t gfp) > +{ > + struct page *page; > + > + page = alloc_page(gfp); > + > + if (page) { > + pool->pages_nr++; > + total_zbud_pages++; Who protect race? > + } > + > + return page; > +} > + > + > /* Resets the struct page fields and frees the page */ > -static void free_zbud_page(struct zbud_header *zhdr) > +static void free_zbud_page(struct zbud_pool *pool, struct zbud_header *zhdr) > { > __free_page(virt_to_page(zhdr)); > + > + pool->pages_nr--; > + total_zbud_pages--; > } > > /* > @@ -279,11 +304,10 @@ int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp, > > /* Couldn't find unbuddied zbud page, create new one */ > spin_unlock(&pool->lock); > - page = alloc_page(gfp); > + page = alloc_zbud_page(pool, gfp); > if (!page) > return -ENOMEM; > spin_lock(&pool->lock); > - pool->pages_nr++; > zhdr = init_zbud_page(page); > bud = FIRST; > > @@ -349,8 +373,7 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle) > if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) { > /* zbud page is empty, free */ > list_del(&zhdr->lru); > - free_zbud_page(zhdr); > - pool->pages_nr--; > + free_zbud_page(pool, zhdr); > } else { > /* Add to unbuddied list */ > freechunks = num_free_chunks(zhdr); > @@ -447,8 +470,7 @@ next: > * Both buddies are now free, free the zbud page and > * return success. > */ > - free_zbud_page(zhdr); > - pool->pages_nr--; > + free_zbud_page(pool, zhdr); > spin_unlock(&pool->lock); > return 0; > } else if (zhdr->first_chunks == 0 || > @@ -496,14 +518,12 @@ void zbud_unmap(struct zbud_pool *pool, unsigned long handle) > > /** > * zbud_get_pool_size() - gets the zbud pool size in pages > - * @pool: pool whose size is being queried > * > - * Returns: size in pages of the given pool. The pool lock need not be > - * taken to access pages_nr. > + * Returns: size in pages of all the zbud pools. > */ > -u64 zbud_get_pool_size(struct zbud_pool *pool) > +u64 zbud_get_pool_size(void) > { > - return pool->pages_nr; > + return total_zbud_pages; > } > > static int __init init_zbud(void) > diff --git a/mm/zswap.c b/mm/zswap.c > index 5a63f78..ef44d9d 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -291,7 +291,7 @@ static void zswap_free_entry(struct zswap_tree *tree, > zbud_free(tree->pool, entry->handle); > zswap_entry_cache_free(entry); > atomic_dec(&zswap_stored_pages); > - zswap_pool_pages = zbud_get_pool_size(tree->pool); > + zswap_pool_pages = zbud_get_pool_size(); > } > > /* caller must hold the tree lock */ > @@ -716,7 +716,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, > > /* update stats */ > atomic_inc(&zswap_stored_pages); > - zswap_pool_pages = zbud_get_pool_size(tree->pool); > + zswap_pool_pages = zbud_get_pool_size(); > > return 0; > > -- > 1.7.10.4 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/