Can you send me the output of "grep . /sys/class/thermal/*/*" both w/ and w/o the broken patch series?
Thanks, rui > -----Original Message----- > From: Laura Abbott [mailto:labb...@redhat.com] > Sent: Thursday, March 17, 2016 6:28 AM > To: Zhang, Rui <rui.zh...@intel.com>; Javi Merino <javi.mer...@arm.com>; > Chen, Yu C <yu.c.c...@intel.com> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>; Manuel Krause > <manuelkra...@netscape.net>; szegad <szega...@poczta.onet.pl>; prash > <prash.n....@gmail.com>; amish <ammdispose-a...@yahoo.com>; Matthias > <morpheusxyz...@yahoo.de>; linux...@vger.kernel.org; Linux Kernel > Mailing List <linux-kernel@vger.kernel.org> > Subject: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device > correctly") causes performance drop > Importance: High > > Hi, > > Fedora received a bug report > (https://bugzilla.redhat.com/show_bug.cgi?id=1317190) > of a major performance drop on various bench marks and general system > sluggishness with the 4.4.4 kernel update. The benchmarks were showing a > reduction to about 18% performance (not minor). > > Bisection showed the first bad commit was > > commit 774ac8b7eff69e0786970157de2157e68b22f456 > Author: Zhang Rui <rui.zh...@intel.com> > Date: Fri Oct 30 16:31:47 2015 +0800 > > Thermal: initialize thermal zone device correctly > > commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream. > > After thermal zone device registered, as we have not read any > temperature before, thus tz->temperature should not be 0, > which actually means 0C, and thermal trend is not available. > In this case, we need specially handling for the first > thermal_zone_device_update(). > > Both thermal core framework and step_wise governor is > enhanced to handle this. And since the step_wise governor > is the only one that uses trends, so it's the only thermal > governor that needs to be updated. > > Tested-by: Manuel Krause <manuelkra...@netscape.net> > Tested-by: szegad <szega...@poczta.onet.pl> > Tested-by: prash <prash.n....@gmail.com> > Tested-by: amish <ammdispose-a...@yahoo.com> > Tested-by: Matthias <morpheusxyz...@yahoo.de> > Reviewed-by: Javi Merino <javi.mer...@arm.com> > Signed-off-by: Zhang Rui <rui.zh...@intel.com> > Signed-off-by: Chen Yu <yu.c.c...@intel.com> > Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > > > Reverting this plus to other commits in the series (a67208e94d94 > "Thermal: handle thermal zone device properly during system sleep" > and 27f356149d59 "Thermal: do thermal zone update after a cooling device > registered") confirmed the performance was back to normal. > > Bugzilla has the full discussion but this comment from one of the reporters > sums it up: > > "In 4.4.3 and prior, my 2.40 MHz processor would fluctuate between > 1000 and 3400 MHz. In 4.4.4, the processor would fluctuate between > 400 and 700 MHz, according to /proc/cpuinfo. > > Setting /sys/devices/system/cpu/cpufreq/policy0/scaling_governor to > performance, instead of the default "powersave" forces the CPU to > 2400 MHz, and improves performance greatly, but still not to the same level > as in 4.4.3." > > Any ideas? > > Thanks, > Laura
