Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759097AbXHPI3Q (ORCPT ); Thu, 16 Aug 2007 04:29:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756066AbXHPI2p (ORCPT ); Thu, 16 Aug 2007 04:28:45 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60299 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764188AbXHPI2n (ORCPT ); Thu, 16 Aug 2007 04:28:43 -0400 Message-Id: <20070816074628.520798000@chello.nl> References: <20070816074525.065850000@chello.nl> User-Agent: quilt/0.45-1 Date: Thu, 16 Aug 2007 09:45:41 +0200 From: Peter Zijlstra To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: miklos@szeredi.hu, akpm@linux-foundation.org, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, a.p.zijlstra@chello.nl, nikita@clusterfs.com, trond.myklebust@fys.uio.no, yingchao.zhou@gmail.com, richard@rsk.demon.co.uk, torvalds@linux-foundation.org Subject: [PATCH 16/23] mm: scalable bdi statistics counters. Content-Disposition: inline; filename=bdi_stat.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4307 Lines: 170 Provide scalable per backing_dev_info statistics counters. Signed-off-by: Peter Zijlstra --- include/linux/backing-dev.h | 85 ++++++++++++++++++++++++++++++++++++++++++-- mm/backing-dev.c | 27 +++++++++++++ 2 files changed, 109 insertions(+), 3 deletions(-) Index: linux-2.6/include/linux/backing-dev.h =================================================================== --- linux-2.6.orig/include/linux/backing-dev.h +++ linux-2.6/include/linux/backing-dev.h @@ -8,6 +8,8 @@ #ifndef _LINUX_BACKING_DEV_H #define _LINUX_BACKING_DEV_H +#include +#include #include struct page; @@ -24,6 +26,12 @@ enum bdi_state { typedef int (congested_fn)(void *, int); +enum bdi_stat_item { + NR_BDI_STAT_ITEMS +}; + +#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids))) + struct backing_dev_info { unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */ unsigned long state; /* Always use atomic bitops on this */ @@ -32,15 +40,86 @@ struct backing_dev_info { void *congested_data; /* Pointer to aux data for congested func */ void (*unplug_io_fn)(struct backing_dev_info *, struct page *); void *unplug_io_data; + + struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS]; }; -static inline int bdi_init(struct backing_dev_info *bdi) +int bdi_init(struct backing_dev_info *bdi); +void bdi_destroy(struct backing_dev_info *bdi); + +static inline void __add_bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item, s64 amount) { - return 0; + __percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH); } -static inline void bdi_destroy(struct backing_dev_info *bdi) +static inline void __inc_bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item) { + __add_bdi_stat(bdi, item, 1); +} + +static inline void inc_bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + unsigned long flags; + + local_irq_save(flags); + __inc_bdi_stat(bdi, item); + local_irq_restore(flags); +} + +static inline void __dec_bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + __add_bdi_stat(bdi, item, -1); +} + +static inline void dec_bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + unsigned long flags; + + local_irq_save(flags); + __dec_bdi_stat(bdi, item); + local_irq_restore(flags); +} + +static inline s64 bdi_stat(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + return percpu_counter_read_positive(&bdi->bdi_stat[item]); +} + +static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + return percpu_counter_sum_positive(&bdi->bdi_stat[item]); +} + +static inline s64 bdi_stat_sum(struct backing_dev_info *bdi, + enum bdi_stat_item item) +{ + s64 sum; + unsigned long flags; + + local_irq_save(flags); + sum = __bdi_stat_sum(bdi, item); + local_irq_restore(flags); + + return sum; +} + +/* + * maximal error of a stat counter. + */ +static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi) +{ +#ifdef CONFIG_SMP + return nr_cpu_ids * BDI_STAT_BATCH; +#else + return 1; +#endif } /* Index: linux-2.6/mm/backing-dev.c =================================================================== --- linux-2.6.orig/mm/backing-dev.c +++ linux-2.6/mm/backing-dev.c @@ -5,6 +5,33 @@ #include #include +int bdi_init(struct backing_dev_info *bdi) +{ + int i, j; + int err; + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) { + err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0); + if (err) { + for (j = 0; j < i; j++) + percpu_counter_destroy(&bdi->bdi_stat[i]); + break; + } + } + + return err; +} +EXPORT_SYMBOL(bdi_init); + +void bdi_destroy(struct backing_dev_info *bdi) +{ + int i; + + for (i = 0; i < NR_BDI_STAT_ITEMS; i++) + percpu_counter_destroy(&bdi->bdi_stat[i]); +} +EXPORT_SYMBOL(bdi_destroy); + static wait_queue_head_t congestion_wqh[2] = { __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) -- - 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/