Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756408AbXK2LOa (ORCPT ); Thu, 29 Nov 2007 06:14:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754832AbXK2LOW (ORCPT ); Thu, 29 Nov 2007 06:14:22 -0500 Received: from fxip-0047f.externet.hu ([88.209.222.127]:55638 "EHLO dorka.pomaz.szeredi.hu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754610AbXK2LOV (ORCPT ); Thu, 29 Nov 2007 06:14:21 -0500 To: a.p.zijlstra@chello.nl CC: fengguang.wu@gmail.com, linux-kernel@vger.kernel.org In-reply-to: (message from Miklos Szeredi on Thu, 29 Nov 2007 12:10:24 +0100) Subject: [patch 2/3] mm: bdi: allow to set a minimum to the bdi dirty limit References: Message-Id: From: Miklos Szeredi Date: Thu, 29 Nov 2007 12:14:18 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3748 Lines: 129 [mszeredi@suse.cz] Fix parsing in min_ratio_store() Signed-off-by: Peter Zijlstra --- Index: linux/include/linux/backing-dev.h =================================================================== --- linux.orig/include/linux/backing-dev.h 2007-11-26 17:24:19.000000000 +0100 +++ linux/include/linux/backing-dev.h 2007-11-26 17:24:39.000000000 +0100 @@ -51,6 +51,8 @@ struct backing_dev_info { struct prop_local_percpu completions; int dirty_exceeded; + unsigned int min_ratio; + struct device *dev; }; @@ -147,6 +149,8 @@ static inline unsigned long bdi_stat_err #endif } +int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio); + /* * Flags in backing_dev_info::capability * - The first two flags control whether dirty pages will contribute to the Index: linux/mm/backing-dev.c =================================================================== --- linux.orig/mm/backing-dev.c 2007-11-26 17:24:19.000000000 +0100 +++ linux/mm/backing-dev.c 2007-11-26 17:24:39.000000000 +0100 @@ -50,6 +50,24 @@ static inline unsigned long get_dirty(st BDI_SHOW(dirty_kb, K(get_dirty(bdi, 1))) BDI_SHOW(bdi_dirty_kb, K(get_dirty(bdi, 2))) +static ssize_t min_ratio_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct backing_dev_info *bdi = dev_get_drvdata(dev); + char *end; + unsigned int ratio; + ssize_t ret = -EINVAL; + + ratio = simple_strtoul(buf, &end, 10); + if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) { + ret = bdi_set_min_ratio(bdi, ratio); + if (!ret) + ret = count; + } + return ret; +} +BDI_SHOW(min_ratio, bdi->min_ratio) + #define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store) static struct device_attribute bdi_dev_attrs[] = { @@ -58,6 +76,7 @@ static struct device_attribute bdi_dev_a __ATTR_RO(writeback_kb), __ATTR_RO(dirty_kb), __ATTR_RO(bdi_dirty_kb), + __ATTR_RW(min_ratio), __ATTR_NULL, }; @@ -199,3 +218,4 @@ long congestion_wait(int rw, long timeou } EXPORT_SYMBOL(congestion_wait); + Index: linux/mm/page-writeback.c =================================================================== --- linux.orig/mm/page-writeback.c 2007-11-26 17:24:19.000000000 +0100 +++ linux/mm/page-writeback.c 2007-11-26 17:24:40.000000000 +0100 @@ -241,6 +241,29 @@ static void task_dirty_limit(struct task } /* + * + */ +static DEFINE_SPINLOCK(bdi_lock); +static unsigned int bdi_min_ratio; + +int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&bdi_lock, flags); + min_ratio -= bdi->min_ratio; + if (bdi_min_ratio + min_ratio < 100) { + bdi_min_ratio += min_ratio; + bdi->min_ratio += min_ratio; + } else + ret = -EINVAL; + spin_unlock_irqrestore(&bdi_lock, flags); + + return ret; +} + +/* * Work out the current dirty-memory clamping and background writeout * thresholds. * @@ -325,7 +348,7 @@ get_dirty_limits(long *pbackground, long *pdirty = dirty; if (bdi) { - u64 bdi_dirty = dirty; + u64 bdi_dirty; long numerator, denominator; /* @@ -333,8 +356,10 @@ get_dirty_limits(long *pbackground, long */ bdi_writeout_fraction(bdi, &numerator, &denominator); + bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; bdi_dirty *= numerator; do_div(bdi_dirty, denominator); + bdi_dirty += (dirty * bdi->min_ratio) / 100; *pbdi_dirty = bdi_dirty; clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty); - 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/