Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752882Ab0HTJdE (ORCPT ); Fri, 20 Aug 2010 05:33:04 -0400 Received: from smtp-out.google.com ([216.239.44.51]:50500 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752606Ab0HTJcc (ORCPT ); Fri, 20 Aug 2010 05:32:32 -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=h8MXBuz7fUAy2MXkBWodDPZgee9kTtHjG749WlKOezsnl90eAr1yndMrxGIHykymK Mlu3n20zxlfpfchm/RbYw== 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, npiggin@kernel.dk, hch@lst.de, axboe@kernel.dk, Michael Rubin Subject: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat Date: Fri, 20 Aug 2010 02:31:29 -0700 Message-Id: <1282296689-25618-5-git-send-email-mrubin@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1282296689-25618-1-git-send-email-mrubin@google.com> References: <1282296689-25618-1-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: 2391 Lines: 70 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 | 3 +++ mm/vmstat.c | 5 +++++ 2 files changed, 8 insertions(+), 0 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index fe4e6dd..c2243d0 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -106,6 +106,9 @@ enum zone_stat_item { NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ NR_FILE_PAGES_DIRTIED, /* number of times pages get dirtied */ NR_PAGES_ENTERED_WRITEBACK, /* 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 073a496..c755d71 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_entered_writeback", + "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_THRESHOLD, v + NR_DIRTY_BG_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/