Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965475Ab2JaN4m (ORCPT ); Wed, 31 Oct 2012 09:56:42 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:32147 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965101Ab2JaN4k (ORCPT ); Wed, 31 Oct 2012 09:56:40 -0400 Date: Wed, 31 Oct 2012 09:42:46 -0400 From: Konrad Rzeszutek Wilk To: Cesar Eduardo Barros Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dan Magenheimer , Mel Gorman , Rik van Riel , KAMEZAWA Hiroyuki , Johannes Weiner Subject: Re: [PATCH RFC] mm: simplify frontswap_init() Message-ID: <20121031134246.GF27288@phenom.dumpdata.com> References: <5090594E.7050401@cesarb.net> <1351638773-3986-1-git-send-email-cesarb@cesarb.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1351638773-3986-1-git-send-email-cesarb@cesarb.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5375 Lines: 150 On Tue, Oct 30, 2012 at 09:12:53PM -0200, Cesar Eduardo Barros wrote: > The function frontswap_init() uses the passed parameter only to check > for the presence of the frontswap_map. It is also passed down to > frontswap_ops.init(), but all implementations of it in the kernel ignore > the parameter. > > Do the check for frontswap_map in the caller instead and remove the > parameter from frontswap_init() and frontswap_ops.init(). > > Also, __frontswap_init() was exported, but its only caller (via an > inline function) is mm/swapfile.c, which cannot be built as a module. > Remove the unnecessary export. > > Signed-off-by: Cesar Eduardo Barros > --- > > Not even compile tested, just a quick patch to show what I was thinking > of, but feel free to apply if you think it is good. That looks good. > > I might write another patch to move it outside the lock later, but I > would have to read the frontswap code more carefully first. > > drivers/staging/ramster/zcache-main.c | 2 +- > drivers/staging/zcache/zcache-main.c | 2 +- > drivers/xen/tmem.c | 2 +- > include/linux/frontswap.h | 8 ++++---- > mm/frontswap.c | 10 ++-------- > mm/swapfile.c | 3 ++- > 6 files changed, 11 insertions(+), 16 deletions(-) > > diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c > index a09dd5c..b3f01c9 100644 > --- a/drivers/staging/ramster/zcache-main.c > +++ b/drivers/staging/ramster/zcache-main.c > @@ -1610,7 +1610,7 @@ static void zcache_frontswap_flush_area(unsigned type) > } > } > > -static void zcache_frontswap_init(unsigned ignored) > +static void zcache_frontswap_init(void) > { > /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ > if (zcache_frontswap_poolid < 0) > diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c > index 52b43b7..cb67635 100644 > --- a/drivers/staging/zcache/zcache-main.c > +++ b/drivers/staging/zcache/zcache-main.c > @@ -1903,7 +1903,7 @@ static void zcache_frontswap_flush_area(unsigned type) > } > } > > -static void zcache_frontswap_init(unsigned ignored) > +static void zcache_frontswap_init(void) > { > /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ > if (zcache_frontswap_poolid < 0) > diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c > index 144564e..7156ff0 100644 > --- a/drivers/xen/tmem.c > +++ b/drivers/xen/tmem.c > @@ -343,7 +343,7 @@ static void tmem_frontswap_flush_area(unsigned type) > (void)xen_tmem_flush_object(pool, oswiz(type, ind)); > } > > -static void tmem_frontswap_init(unsigned ignored) > +static void tmem_frontswap_init(void) > { > struct tmem_pool_uuid private = TMEM_POOL_PRIVATE_UUID; > > diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h > index 3044254..6374c80 100644 > --- a/include/linux/frontswap.h > +++ b/include/linux/frontswap.h > @@ -6,7 +6,7 @@ > #include > > struct frontswap_ops { > - void (*init)(unsigned); > + void (*init)(void); > int (*store)(unsigned, pgoff_t, struct page *); > int (*load)(unsigned, pgoff_t, struct page *); > void (*invalidate_page)(unsigned, pgoff_t); > @@ -22,7 +22,7 @@ extern void frontswap_writethrough(bool); > #define FRONTSWAP_HAS_EXCLUSIVE_GETS > extern void frontswap_tmem_exclusive_gets(bool); > > -extern void __frontswap_init(unsigned type); > +extern void __frontswap_init(void); > extern int __frontswap_store(struct page *page); > extern int __frontswap_load(struct page *page); > extern void __frontswap_invalidate_page(unsigned, pgoff_t); > @@ -120,10 +120,10 @@ static inline void frontswap_invalidate_area(unsigned type) > __frontswap_invalidate_area(type); > } > > -static inline void frontswap_init(unsigned type) > +static inline void frontswap_init(void) > { > if (frontswap_enabled) > - __frontswap_init(type); > + __frontswap_init(); > } > > #endif /* _LINUX_FRONTSWAP_H */ > diff --git a/mm/frontswap.c b/mm/frontswap.c > index 2890e67..d13661b 100644 > --- a/mm/frontswap.c > +++ b/mm/frontswap.c > @@ -115,16 +115,10 @@ EXPORT_SYMBOL(frontswap_tmem_exclusive_gets); > /* > * Called when a swap device is swapon'd. > */ > -void __frontswap_init(unsigned type) > +void __frontswap_init(void) > { > - struct swap_info_struct *sis = swap_info[type]; > - > - BUG_ON(sis == NULL); > - if (sis->frontswap_map == NULL) > - return; > - frontswap_ops.init(type); > + frontswap_ops.init(); > } > -EXPORT_SYMBOL(__frontswap_init); > > static inline void __frontswap_clear(struct swap_info_struct *sis, pgoff_t offset) > { > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 088daf4..28c26bd 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1479,7 +1479,8 @@ static void enable_swap_info(struct swap_info_struct *p, int prio, > { > spin_lock(&swap_lock); > _enable_swap_info(p, prio, swap_map, frontswap_map); > - frontswap_init(p->type); > + if (frontswap_map) > + frontswap_init(); > spin_unlock(&swap_lock); > } > > -- > 1.7.11.7 -- 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/