Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753429Ab0H1Cln (ORCPT ); Fri, 27 Aug 2010 22:41:43 -0400 Received: from smtp-out.google.com ([216.239.44.51]:10276 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753251Ab0H1ClO (ORCPT ); Fri, 27 Aug 2010 22:41:14 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=N+CwSa1CnWBhVyCdPP5XtXs79cnSN/e/xLdYPthN1C4EYxDEln4q2S1wV/LOHkRFD 7xKlAyj9PXGc8AECbTfKg== From: Michael Rubin To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: fengguang.wu@intel.com, jack@suse.cz, riel@redhat.com, akpm@linux-foundation.org, david@fromorbit.com, kosaki.motohiro@jp.fujitsu.com, npiggin@kernel.dk, hch@lst.de, axboe@kernel.dk, Michael Rubin Subject: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat Date: Fri, 27 Aug 2010 19:40:27 -0700 Message-Id: <1282963227-31867-5-git-send-email-mrubin@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1282963227-31867-1-git-send-email-mrubin@google.com> References: <1282963227-31867-1-git-send-email-mrubin@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2389 Lines: 69 The kernel already exposes the user desired thresholds in /proc/sys/vm with dirty_background_ratio and background_ratio. But the kernel may alter the number requested without giving the user any indication that is the case. Knowing the actual ratios the kernel is honoring can help app developers understand how their buffered IO will be sent to the disk. $ grep threshold /proc/vmstat nr_dirty_threshold 409111 nr_dirty_background_threshold 818223 Signed-off-by: Michael Rubin --- include/linux/mmzone.h | 2 ++ mm/vmstat.c | 5 +++++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index d42f179..ad48963 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -106,6 +106,8 @@ enum zone_stat_item { NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ NR_FILE_PAGES_DIRTIED, /* number of times pages get dirtied */ NR_PAGES_CLEANED, /* number of times pages enter writeback */ + NR_DIRTY_THRESHOLD, /* writeback threshold */ + NR_DIRTY_BG_THRESHOLD, /* bg writeback threshold */ #ifdef CONFIG_NUMA NUMA_HIT, /* allocated in intended node */ NUMA_MISS, /* allocated in non intended node */ diff --git a/mm/vmstat.c b/mm/vmstat.c index 8521475..2342010 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -17,6 +17,7 @@ #include #include #include +#include #ifdef CONFIG_VM_EVENT_COUNTERS DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; @@ -734,6 +735,8 @@ static const char * const vmstat_text[] = { "nr_shmem", "nr_dirtied", "nr_cleaned", + "nr_dirty_threshold", + "nr_dirty_background_threshold", #ifdef CONFIG_NUMA "numa_hit", @@ -917,6 +920,8 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos) return ERR_PTR(-ENOMEM); for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) v[i] = global_page_state(i); + + global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, v + NR_DIRTY_THRESHOLD); #ifdef CONFIG_VM_EVENT_COUNTERS e = v + NR_VM_ZONE_STAT_ITEMS; all_vm_events(e); -- 1.7.1 -- 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/