Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753332AbaKCQ5w (ORCPT ); Mon, 3 Nov 2014 11:57:52 -0500 Received: from cantor2.suse.de ([195.135.220.15]:56625 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752720AbaKCQ5c (ORCPT ); Mon, 3 Nov 2014 11:57:32 -0500 Date: Mon, 3 Nov 2014 17:57:31 +0100 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Vladimir Davydov , Tejun Heo , David Miller , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 2/3] mm: page_cgroup: rename file to mm/swap_cgroup.c Message-ID: <20141103165731.GF10156@dhcp22.suse.cz> References: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> <1414898156-4741-2-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414898156-4741-2-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 01-11-14 23:15:55, Johannes Weiner wrote: > Now that the external page_cgroup data structure and its lookup is > gone, the only code remaining in there is swap slot accounting. > > Rename it and move the conditional compilation into mm/Makefile. > > Signed-off-by: Johannes Weiner Acked-by: Michal Hocko > --- > MAINTAINERS | 2 +- > include/linux/page_cgroup.h | 40 --------- > include/linux/swap_cgroup.h | 42 +++++++++ > mm/Makefile | 3 +- > mm/memcontrol.c | 2 +- > mm/page_cgroup.c | 211 -------------------------------------------- > mm/swap_cgroup.c | 208 +++++++++++++++++++++++++++++++++++++++++++ > mm/swap_state.c | 1 - > mm/swapfile.c | 2 +- > 9 files changed, 255 insertions(+), 256 deletions(-) > delete mode 100644 include/linux/page_cgroup.h > create mode 100644 include/linux/swap_cgroup.h > delete mode 100644 mm/page_cgroup.c > create mode 100644 mm/swap_cgroup.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 7e31be07197e..3a60389d3a13 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2583,7 +2583,7 @@ L: cgroups@vger.kernel.org > L: linux-mm@kvack.org > S: Maintained > F: mm/memcontrol.c > -F: mm/page_cgroup.c > +F: mm/swap_cgroup.c > > CORETEMP HARDWARE MONITORING DRIVER > M: Fenghua Yu > diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h > deleted file mode 100644 > index 65be35785c86..000000000000 > --- a/include/linux/page_cgroup.h > +++ /dev/null > @@ -1,40 +0,0 @@ > -#ifndef __LINUX_PAGE_CGROUP_H > -#define __LINUX_PAGE_CGROUP_H > - > -#include > - > -#ifdef CONFIG_MEMCG_SWAP > -extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, > - unsigned short old, unsigned short new); > -extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id); > -extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent); > -extern int swap_cgroup_swapon(int type, unsigned long max_pages); > -extern void swap_cgroup_swapoff(int type); > -#else > - > -static inline > -unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) > -{ > - return 0; > -} > - > -static inline > -unsigned short lookup_swap_cgroup_id(swp_entry_t ent) > -{ > - return 0; > -} > - > -static inline int > -swap_cgroup_swapon(int type, unsigned long max_pages) > -{ > - return 0; > -} > - > -static inline void swap_cgroup_swapoff(int type) > -{ > - return; > -} > - > -#endif /* CONFIG_MEMCG_SWAP */ > - > -#endif /* __LINUX_PAGE_CGROUP_H */ > diff --git a/include/linux/swap_cgroup.h b/include/linux/swap_cgroup.h > new file mode 100644 > index 000000000000..145306bdc92f > --- /dev/null > +++ b/include/linux/swap_cgroup.h > @@ -0,0 +1,42 @@ > +#ifndef __LINUX_SWAP_CGROUP_H > +#define __LINUX_SWAP_CGROUP_H > + > +#include > + > +#ifdef CONFIG_MEMCG_SWAP > + > +extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, > + unsigned short old, unsigned short new); > +extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id); > +extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent); > +extern int swap_cgroup_swapon(int type, unsigned long max_pages); > +extern void swap_cgroup_swapoff(int type); > + > +#else > + > +static inline > +unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) > +{ > + return 0; > +} > + > +static inline > +unsigned short lookup_swap_cgroup_id(swp_entry_t ent) > +{ > + return 0; > +} > + > +static inline int > +swap_cgroup_swapon(int type, unsigned long max_pages) > +{ > + return 0; > +} > + > +static inline void swap_cgroup_swapoff(int type) > +{ > + return; > +} > + > +#endif /* CONFIG_MEMCG_SWAP */ > + > +#endif /* __LINUX_SWAP_CGROUP_H */ > diff --git a/mm/Makefile b/mm/Makefile > index 27ddb80403a9..d9d579484f15 100644 > --- a/mm/Makefile > +++ b/mm/Makefile > @@ -56,7 +56,8 @@ obj-$(CONFIG_MIGRATION) += migrate.o > obj-$(CONFIG_QUICKLIST) += quicklist.o > obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o > obj-$(CONFIG_PAGE_COUNTER) += page_counter.o > -obj-$(CONFIG_MEMCG) += memcontrol.o page_cgroup.o vmpressure.o > +obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o > +obj-$(CONFIG_MEMCG_SWAP) += swap_cgroup.o > obj-$(CONFIG_CGROUP_HUGETLB) += hugetlb_cgroup.o > obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o > obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index dc5e0abb18cb..fbb41a170eae 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -51,7 +51,7 @@ > #include > #include > #include > -#include > +#include > #include > #include > #include > diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c > deleted file mode 100644 > index f0f31c1d4d0c..000000000000 > --- a/mm/page_cgroup.c > +++ /dev/null > @@ -1,211 +0,0 @@ > -#include > -#include > -#include > -#include > - > -#ifdef CONFIG_MEMCG_SWAP > - > -static DEFINE_MUTEX(swap_cgroup_mutex); > -struct swap_cgroup_ctrl { > - struct page **map; > - unsigned long length; > - spinlock_t lock; > -}; > - > -static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES]; > - > -struct swap_cgroup { > - unsigned short id; > -}; > -#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup)) > - > -/* > - * SwapCgroup implements "lookup" and "exchange" operations. > - * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge > - * against SwapCache. At swap_free(), this is accessed directly from swap. > - * > - * This means, > - * - we have no race in "exchange" when we're accessed via SwapCache because > - * SwapCache(and its swp_entry) is under lock. > - * - When called via swap_free(), there is no user of this entry and no race. > - * Then, we don't need lock around "exchange". > - * > - * TODO: we can push these buffers out to HIGHMEM. > - */ > - > -/* > - * allocate buffer for swap_cgroup. > - */ > -static int swap_cgroup_prepare(int type) > -{ > - struct page *page; > - struct swap_cgroup_ctrl *ctrl; > - unsigned long idx, max; > - > - ctrl = &swap_cgroup_ctrl[type]; > - > - for (idx = 0; idx < ctrl->length; idx++) { > - page = alloc_page(GFP_KERNEL | __GFP_ZERO); > - if (!page) > - goto not_enough_page; > - ctrl->map[idx] = page; > - } > - return 0; > -not_enough_page: > - max = idx; > - for (idx = 0; idx < max; idx++) > - __free_page(ctrl->map[idx]); > - > - return -ENOMEM; > -} > - > -static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent, > - struct swap_cgroup_ctrl **ctrlp) > -{ > - pgoff_t offset = swp_offset(ent); > - struct swap_cgroup_ctrl *ctrl; > - struct page *mappage; > - struct swap_cgroup *sc; > - > - ctrl = &swap_cgroup_ctrl[swp_type(ent)]; > - if (ctrlp) > - *ctrlp = ctrl; > - > - mappage = ctrl->map[offset / SC_PER_PAGE]; > - sc = page_address(mappage); > - return sc + offset % SC_PER_PAGE; > -} > - > -/** > - * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry. > - * @ent: swap entry to be cmpxchged > - * @old: old id > - * @new: new id > - * > - * Returns old id at success, 0 at failure. > - * (There is no mem_cgroup using 0 as its id) > - */ > -unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, > - unsigned short old, unsigned short new) > -{ > - struct swap_cgroup_ctrl *ctrl; > - struct swap_cgroup *sc; > - unsigned long flags; > - unsigned short retval; > - > - sc = lookup_swap_cgroup(ent, &ctrl); > - > - spin_lock_irqsave(&ctrl->lock, flags); > - retval = sc->id; > - if (retval == old) > - sc->id = new; > - else > - retval = 0; > - spin_unlock_irqrestore(&ctrl->lock, flags); > - return retval; > -} > - > -/** > - * swap_cgroup_record - record mem_cgroup for this swp_entry. > - * @ent: swap entry to be recorded into > - * @id: mem_cgroup to be recorded > - * > - * Returns old value at success, 0 at failure. > - * (Of course, old value can be 0.) > - */ > -unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) > -{ > - struct swap_cgroup_ctrl *ctrl; > - struct swap_cgroup *sc; > - unsigned short old; > - unsigned long flags; > - > - sc = lookup_swap_cgroup(ent, &ctrl); > - > - spin_lock_irqsave(&ctrl->lock, flags); > - old = sc->id; > - sc->id = id; > - spin_unlock_irqrestore(&ctrl->lock, flags); > - > - return old; > -} > - > -/** > - * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry > - * @ent: swap entry to be looked up. > - * > - * Returns ID of mem_cgroup at success. 0 at failure. (0 is invalid ID) > - */ > -unsigned short lookup_swap_cgroup_id(swp_entry_t ent) > -{ > - return lookup_swap_cgroup(ent, NULL)->id; > -} > - > -int swap_cgroup_swapon(int type, unsigned long max_pages) > -{ > - void *array; > - unsigned long array_size; > - unsigned long length; > - struct swap_cgroup_ctrl *ctrl; > - > - if (!do_swap_account) > - return 0; > - > - length = DIV_ROUND_UP(max_pages, SC_PER_PAGE); > - array_size = length * sizeof(void *); > - > - array = vzalloc(array_size); > - if (!array) > - goto nomem; > - > - ctrl = &swap_cgroup_ctrl[type]; > - mutex_lock(&swap_cgroup_mutex); > - ctrl->length = length; > - ctrl->map = array; > - spin_lock_init(&ctrl->lock); > - if (swap_cgroup_prepare(type)) { > - /* memory shortage */ > - ctrl->map = NULL; > - ctrl->length = 0; > - mutex_unlock(&swap_cgroup_mutex); > - vfree(array); > - goto nomem; > - } > - mutex_unlock(&swap_cgroup_mutex); > - > - return 0; > -nomem: > - printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n"); > - printk(KERN_INFO > - "swap_cgroup can be disabled by swapaccount=0 boot option\n"); > - return -ENOMEM; > -} > - > -void swap_cgroup_swapoff(int type) > -{ > - struct page **map; > - unsigned long i, length; > - struct swap_cgroup_ctrl *ctrl; > - > - if (!do_swap_account) > - return; > - > - mutex_lock(&swap_cgroup_mutex); > - ctrl = &swap_cgroup_ctrl[type]; > - map = ctrl->map; > - length = ctrl->length; > - ctrl->map = NULL; > - ctrl->length = 0; > - mutex_unlock(&swap_cgroup_mutex); > - > - if (map) { > - for (i = 0; i < length; i++) { > - struct page *page = map[i]; > - if (page) > - __free_page(page); > - } > - vfree(map); > - } > -} > - > -#endif > diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c > new file mode 100644 > index 000000000000..b5f7f24b8dd1 > --- /dev/null > +++ b/mm/swap_cgroup.c > @@ -0,0 +1,208 @@ > +#include > +#include > +#include > + > +#include /* depends on mm.h include */ > + > +static DEFINE_MUTEX(swap_cgroup_mutex); > +struct swap_cgroup_ctrl { > + struct page **map; > + unsigned long length; > + spinlock_t lock; > +}; > + > +static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES]; > + > +struct swap_cgroup { > + unsigned short id; > +}; > +#define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup)) > + > +/* > + * SwapCgroup implements "lookup" and "exchange" operations. > + * In typical usage, this swap_cgroup is accessed via memcg's charge/uncharge > + * against SwapCache. At swap_free(), this is accessed directly from swap. > + * > + * This means, > + * - we have no race in "exchange" when we're accessed via SwapCache because > + * SwapCache(and its swp_entry) is under lock. > + * - When called via swap_free(), there is no user of this entry and no race. > + * Then, we don't need lock around "exchange". > + * > + * TODO: we can push these buffers out to HIGHMEM. > + */ > + > +/* > + * allocate buffer for swap_cgroup. > + */ > +static int swap_cgroup_prepare(int type) > +{ > + struct page *page; > + struct swap_cgroup_ctrl *ctrl; > + unsigned long idx, max; > + > + ctrl = &swap_cgroup_ctrl[type]; > + > + for (idx = 0; idx < ctrl->length; idx++) { > + page = alloc_page(GFP_KERNEL | __GFP_ZERO); > + if (!page) > + goto not_enough_page; > + ctrl->map[idx] = page; > + } > + return 0; > +not_enough_page: > + max = idx; > + for (idx = 0; idx < max; idx++) > + __free_page(ctrl->map[idx]); > + > + return -ENOMEM; > +} > + > +static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent, > + struct swap_cgroup_ctrl **ctrlp) > +{ > + pgoff_t offset = swp_offset(ent); > + struct swap_cgroup_ctrl *ctrl; > + struct page *mappage; > + struct swap_cgroup *sc; > + > + ctrl = &swap_cgroup_ctrl[swp_type(ent)]; > + if (ctrlp) > + *ctrlp = ctrl; > + > + mappage = ctrl->map[offset / SC_PER_PAGE]; > + sc = page_address(mappage); > + return sc + offset % SC_PER_PAGE; > +} > + > +/** > + * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry. > + * @ent: swap entry to be cmpxchged > + * @old: old id > + * @new: new id > + * > + * Returns old id at success, 0 at failure. > + * (There is no mem_cgroup using 0 as its id) > + */ > +unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, > + unsigned short old, unsigned short new) > +{ > + struct swap_cgroup_ctrl *ctrl; > + struct swap_cgroup *sc; > + unsigned long flags; > + unsigned short retval; > + > + sc = lookup_swap_cgroup(ent, &ctrl); > + > + spin_lock_irqsave(&ctrl->lock, flags); > + retval = sc->id; > + if (retval == old) > + sc->id = new; > + else > + retval = 0; > + spin_unlock_irqrestore(&ctrl->lock, flags); > + return retval; > +} > + > +/** > + * swap_cgroup_record - record mem_cgroup for this swp_entry. > + * @ent: swap entry to be recorded into > + * @id: mem_cgroup to be recorded > + * > + * Returns old value at success, 0 at failure. > + * (Of course, old value can be 0.) > + */ > +unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) > +{ > + struct swap_cgroup_ctrl *ctrl; > + struct swap_cgroup *sc; > + unsigned short old; > + unsigned long flags; > + > + sc = lookup_swap_cgroup(ent, &ctrl); > + > + spin_lock_irqsave(&ctrl->lock, flags); > + old = sc->id; > + sc->id = id; > + spin_unlock_irqrestore(&ctrl->lock, flags); > + > + return old; > +} > + > +/** > + * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry > + * @ent: swap entry to be looked up. > + * > + * Returns ID of mem_cgroup at success. 0 at failure. (0 is invalid ID) > + */ > +unsigned short lookup_swap_cgroup_id(swp_entry_t ent) > +{ > + return lookup_swap_cgroup(ent, NULL)->id; > +} > + > +int swap_cgroup_swapon(int type, unsigned long max_pages) > +{ > + void *array; > + unsigned long array_size; > + unsigned long length; > + struct swap_cgroup_ctrl *ctrl; > + > + if (!do_swap_account) > + return 0; > + > + length = DIV_ROUND_UP(max_pages, SC_PER_PAGE); > + array_size = length * sizeof(void *); > + > + array = vzalloc(array_size); > + if (!array) > + goto nomem; > + > + ctrl = &swap_cgroup_ctrl[type]; > + mutex_lock(&swap_cgroup_mutex); > + ctrl->length = length; > + ctrl->map = array; > + spin_lock_init(&ctrl->lock); > + if (swap_cgroup_prepare(type)) { > + /* memory shortage */ > + ctrl->map = NULL; > + ctrl->length = 0; > + mutex_unlock(&swap_cgroup_mutex); > + vfree(array); > + goto nomem; > + } > + mutex_unlock(&swap_cgroup_mutex); > + > + return 0; > +nomem: > + printk(KERN_INFO "couldn't allocate enough memory for swap_cgroup.\n"); > + printk(KERN_INFO > + "swap_cgroup can be disabled by swapaccount=0 boot option\n"); > + return -ENOMEM; > +} > + > +void swap_cgroup_swapoff(int type) > +{ > + struct page **map; > + unsigned long i, length; > + struct swap_cgroup_ctrl *ctrl; > + > + if (!do_swap_account) > + return; > + > + mutex_lock(&swap_cgroup_mutex); > + ctrl = &swap_cgroup_ctrl[type]; > + map = ctrl->map; > + length = ctrl->length; > + ctrl->map = NULL; > + ctrl->length = 0; > + mutex_unlock(&swap_cgroup_mutex); > + > + if (map) { > + for (i = 0; i < length; i++) { > + struct page *page = map[i]; > + if (page) > + __free_page(page); > + } > + vfree(map); > + } > +} > diff --git a/mm/swap_state.c b/mm/swap_state.c > index 154444918685..9711342987a0 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -17,7 +17,6 @@ > #include > #include > #include > -#include > > #include > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 8798b2e0ac59..63f55ccb9b26 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -38,7 +38,7 @@ > #include > #include > #include > -#include > +#include > > static bool swap_count_continued(struct swap_info_struct *, pgoff_t, > unsigned char); > -- > 2.1.3 > -- Michal Hocko SUSE Labs -- 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/