From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: Justin Forbes <jmforbes@linuxtx.org>,
Zwane Mwaikambo <zwane@arm.linux.org.uk>,
"Theodore Ts'o" <tytso@mit.edu>,
Randy Dunlap <rdunlap@xenotime.net>,
Dave Jones <davej@redhat.com>,
Chuck Wolber <chuckw@quantumlinux.com>,
Chris Wedgwood <reviews@ml.cw.f00f.org>,
Michael Krufky <mkrufky@linuxtv.org>,
Chuck Ebbert <cebbert@redhat.com>,
Domenico Andreoli <cavokz@gmail.com>,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk,
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Subject: [patch 12/12] CPUFREQ: ondemand: add a check to avoid negative load calculation
Date: Tue, 14 Aug 2007 00:29:35 -0700 [thread overview]
Message-ID: <20070814072935.GJ15025@kroah.com> (raw)
In-Reply-To: <20070814072813.GA15025@kroah.com>
[-- Attachment #1: cpufreq-ondemand-add-a-check-to-avoid-negative-load-calculation.patch --]
[-- Type: text/plain, Size: 1308 bytes --]
-stable review patch. If anyone has any objections, please let us know.
------------------
From: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Due to rounding and inexact jiffy accounting, idle_ticks can sometimes
be higher than total_ticks. Make sure those cases are handled as
zero load case.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/cpufreq/cpufreq_ondemand.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -335,7 +335,7 @@ static struct attribute_group dbs_attr_g
static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
unsigned int idle_ticks, total_ticks;
- unsigned int load;
+ unsigned int load = 0;
cputime64_t cur_jiffies;
struct cpufreq_policy *policy;
@@ -381,7 +381,8 @@ static void dbs_check_cpu(struct cpu_dbs
if (tmp_idle_ticks < idle_ticks)
idle_ticks = tmp_idle_ticks;
}
- load = (100 * (total_ticks - idle_ticks)) / total_ticks;
+ if (likely(total_ticks > idle_ticks))
+ load = (100 * (total_ticks - idle_ticks)) / total_ticks;
/* Check for frequency increase */
if (load > dbs_tuners_ins.up_threshold) {
--
next prev parent reply other threads:[~2007-08-14 7:52 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070814072244.882283903@mini.kroah.org>
2007-08-14 7:28 ` [patch 00/12] 2.6.22-stable review Greg KH
2007-08-14 7:28 ` [patch 01/12] fix oops in __audit_signal_info() Greg KH
2007-08-14 7:28 ` [patch 02/12] random: fix bound check ordering (CVE-2007-3105) Greg KH
2007-08-14 7:28 ` [patch 03/12] softmac: Fix deadlock of wx_set_essid with assoc work Greg KH
2007-08-14 7:28 ` Greg KH
2007-08-14 7:29 ` [patch 04/12] ata_piix: update map 10b for ich8m Greg KH
2007-08-14 7:29 ` [patch 05/12] PPC: Revert "Dont complain if size-cells == 0 in prom_parse()" Greg KH
2007-08-14 7:29 ` [patch 07/12] powerpc: Fix size check for hugetlbfs Greg KH
2007-08-14 7:29 ` Greg KH
2007-08-14 7:56 ` David Gibson
2007-08-14 7:56 ` David Gibson
2007-08-14 7:29 ` [patch 06/12] PPC: Revert "Add mdio to bus scan id list for platforms with QE UEC" Greg KH
2007-08-14 7:29 ` [patch 08/12] direct-io: fix error-path crashes Greg KH
2007-08-14 7:29 ` Greg KH [this message]
2007-08-14 7:29 ` [patch 11/12] CPUFREQ: ondemand: fix tickless accounting and software coordination bug Greg KH
2007-08-14 7:29 ` [patch 10/12] pata_atiixp: add SB700 PCI ID Greg KH
2007-08-14 7:29 ` [patch 09/12] stifb: detect cards in double buffer mode more reliably Greg KH
2007-08-14 16:13 ` [patch 00/12] 2.6.22-stable review Prakash Punnoor
2007-08-14 16:04 ` Greg KH
2007-08-14 17:02 ` Prakash Punnoor
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