linaro-dev October 2012

linaro-dev@lists.linaro.org

76 participants
108 discussions

[PATCH 1/5] cpuidle / ACPI : remove unused definition

by Daniel Lezcano

The different definitions are not used anywhere in the code. Signed-off-by: Daniel Lezcano <daniel.lezcano(a)linaro.org> --- drivers/acpi/processor_idle.c | 7 ------- 1 files changed, 0 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index e8086c7..1f536a3 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -60,14 +60,7 @@ #include <asm/processor.h> #define PREFIX "ACPI: " - -#define ACPI_PROCESSOR_CLASS "processor" -#define _COMPONENT ACPI_PROCESSOR_COMPONENT ACPI_MODULE_NAME("processor_idle"); -#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY) -#define C2_OVERHEAD 1 /* 1us */ -#define C3_OVERHEAD 1 /* 1us */ -#define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000)) static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; module_param(max_cstate, uint, 0000); -- 1.7.5.4

12 years, 1 month

[PATCH] x86 : remove dead code

by Daniel Lezcano

The hlt_use_halt function returns always true and there is only one definition of it. The default_idle function can then get ride of the if ... statement and we can remove the else branch. Signed-off-by: Daniel Lezcano <daniel.lezcano(a)linaro.org> --- arch/x86/kernel/process.c | 39 ++++++++++++++------------------------- 1 files changed, 14 insertions(+), 25 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index b644e1c..2f99e31 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -306,11 +306,6 @@ void (*pm_idle)(void); EXPORT_SYMBOL(pm_idle); #endif -static inline int hlt_use_halt(void) -{ - return 1; -} - #ifndef CONFIG_SMP static inline void play_dead(void) { @@ -410,28 +405,22 @@ void cpu_idle(void) */ void default_idle(void) { - if (hlt_use_halt()) { - trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id()); - trace_cpu_idle_rcuidle(1, smp_processor_id()); - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); + trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id()); + trace_cpu_idle_rcuidle(1, smp_processor_id()); + current_thread_info()->status &= ~TS_POLLING; + /* + * TS_POLLING-cleared state must be visible before we + * test NEED_RESCHED: + */ + smp_mb(); - if (!need_resched()) - safe_halt(); /* enables interrupts racelessly */ - else - local_irq_enable(); - current_thread_info()->status |= TS_POLLING; - trace_power_end_rcuidle(smp_processor_id()); - trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); - } else { + if (!need_resched()) + safe_halt(); /* enables interrupts racelessly */ + else local_irq_enable(); - /* loop is done by the caller */ - cpu_relax(); - } + current_thread_info()->status |= TS_POLLING; + trace_power_end_rcuidle(smp_processor_id()); + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); } #ifdef CONFIG_APM_MODULE EXPORT_SYMBOL(default_idle); -- 1.7.5.4

12 years, 1 month

git.l.o: please add post-update hooks to run git-update-server-info

by Loïc Minier

Hi all! An user reported problems cloning a tree from git.linaro.org today with a /git-ro URL: git clone http://git.linaro.org/git-ro/people/foo/bar.git He was getting: fatal: http://git.linaro.org/git-ro/people/foo/bar.git/info/refs not found: did you run git update-server-info on the server? This is because by default, git repos wont be kept up-to-date for http access. The fix is trivial, it's a matter of enabling a "post-update hook" which will run "git update-server-info" in this repo whenever you push new commits. There should already be a template to do this readily available just after you create a new git repo; just remember to run: cd /srv/git.linaro.org/git/foo/bar.git mv hooks/post-update.sample hooks/post-update Below is a list of affected repos; I prefer not fixing them because I don't have enough permissions to do this on all repos, and because you will have to do it for new repos anyway :-) find -L /srv/git.linaro.org/git -iname \*.git -type d | while read d; do [ -e $d/hooks/post-update ] || echo $d; done people/danilo/android-manifest.git people/danilo/android.git people/mansson/snowball/ltp.git people/afrantzis/apitrace.git people/dlezcano/pm-qa.git people/dlezcano/cpuidle-next.git people/dlezcano/linux-next.git people/kurt-r-taylor/android-ucm.git people/kurt-r-taylor/alsa-ucm.git people/kurt-r-taylor/alsa-ucm-utils.git people/dmart/linux-3-arm.git people/dmart/linux-2.6.git people/dmart/linux-2.6-arm.git people/dmart/tunsetup.git people/dmart/arm-virt-bl.git people/dmart/boot-wrapper.git people/arnd/flashbench.git people/arnd/imx.git people/arnd/demo.git people/arnd/arm-soc.git people/niklashernaeus/snowball-device-tree.git people/ljones/linux-2.6.38-ux500.git people/ljones/landingteamtools.git people/ljones/linux-3.0-ux500.git people/ljones/linux-2.6.35-ux500.git people/sariohu/ffmpeg-0.6.1.git people/sariohu/gstreamer0-11.git people/sariohu/xbmc.git people/sariohu/gst-plugins-base0-11.git people/sariohu/gst-plugins-good0-11.git people/sariohu/aacenc.git people/mszyprowski/linux-archive.git people/gesha/mynewproject/.git people/bgaignard/ion_test_application.git people/bgaignard/gst-openmax-0.10.x.git people/bgaignard/lava_realvideo_test.git people/tushar/umm-zero-copy-demo.git people/fboudra/ioquake3.git people/fboudra/irrlicht-gles.git people/fboudra/release-and-project-management.git people/fboudra/ogre3d-gles.git people/fboudra/ioquake3-gles.git people/sumitsemwal/linux-3.x.git people/sumitsemwal/linux-dma-buf.git people/vingu/kernel.git people/shawnguo/linux-2.6.git people/tomgall/meego/libresource.git people/tomgall/meego/contextkit.git people/tomgall/meego/libresourceqt.git people/tomgall/meego/libmeegotouch.git people/tomgall/meego/libjpeg-turbo.git people/tomgall/meego/meegotouch-compositor.git people/tomgall/libjpeg-turbo-leb/libjpeg-turbo.git people/pawelmoll/linux.git people/jstultz/android-dev.git people/jstultz/linux.git people/jstultz/android.git people/jcrigby/kernel-package-info.git people/jcrigby/ubuntu-packaging-ci-upstreams.git people/jcrigby/linaro-boot-utils.git people/jcrigby/linux-lt-ci-pack-info.git people/jcrigby/ubuntu/linux-linaro-oneiric.git people/jcrigby/ubuntu/future-linux-linaro-precise-3.2.git people/jcrigby/ubuntu/linux-history.git people/jcrigby/ubuntu/linux-linaro-quantal.git people/jcrigby/ubuntu/linux-linaro-precise.git people/jcrigby/ubuntu/linux-meta-linaro-natty.git people/jcrigby/linux-lt.git people/jcrigby/null-packaging.git people/jcrigby/ubuntu-kernel-ci.git people/nico/linux.git people/weifeng/bellagio_components.git people/weifeng/gst-plugins-gl.git people/weifeng/gst-openmax.git people/weifeng/kernel.git people/weifeng/alsa-ucm-test.git people/weifeng/pulseaudio.git people/pfalcon/android/platform/manifest.git people/pfalcon/android/linaro/build-configs.git people/andygreen/arm-probe.git people/andygreen/repo-branch-archive.git people/andygreen/lt-tools.git people/chaoyang/jpeg.git people/chaoyang/libpng.git people/bernhardrosenkranzer/repo-branch-archive.git people/salgado/patchwork.git people/mpoirier/snowball/linux-integration-3.0-ux500-androidized.git people/mpoirier/u-boot-v2011.06.git people/mpoirier/linux-ubuntu-3.0.n900.git people/ryanharkin/stm.git people/ryanharkin/repo-branch-archive.git people/ryanharkin/uefi-config.git people/mwaddel/u-boot.git people/rmk/linux-arm.git people/tixy/u-boot.git people/tixy/linux.git people/tixy/android-common.git people/tixy/uefi.git people/tixy/android-manifest.git people/tixy/android-vexpress-a9.git people/tixy/kernel.git people/tixy/android-kernel.git people/triad/linux-stericsson.git people/triad/linux-pinctrl.git people/planglais/linux-tb-ux500.git people/paulliu/linux-2.6.git people/rsalveti/linux-linaro-3.0.git people/mbriand/linux-2.6-arm.git people/pmaydell/qemu-arm.git people/pmaydell/boot-wrapper.git people/hrw/cross-toolchain-packaging.git people/asac/android/external/skia.git people/asac/android/packages/apps/Launcher.git people/asac/android/kernel/lt-ti.git people/asac/android/kernel/pandroid.git people/asac/android/u-boot/pandroid.git people/rusty/qemu-linaro.git people/sachin/linux-linaro.git people/sachin/linux-kernel-samsung.git people/sachin/linux-linaro-2.6.36.git people/sachin/linux-linaro-3.0.git people/sachin/linux-linaro-2.6.38.git people/sachin/linux-linaro-3.1.git people/jserv/omap4-frameworks-base.git people/amitdanielk/thermal-test.git people/amitdanielk/linux.git people/amitdanielk/pm-qa-thermal.git people/amitdanielk/library/libnl.git people/amitdanielk/powertop.git people/patrikryd/b2r2lib.git people/patrikryd/panda.git people/patrikryd/pandaboard.git people/patrikryd/build.git people/riczhao/linux-2.6.git people/chunsangjeong/gralloc-dev.git people/sudip-jain/smartt-old.git people/mandeep-ti/libjpeg_8b_neon.git people/ronynandy/speex.git people/ronynandy/u-boot-arndale.git people/ronynandy/edk2-origen.git people/ronynandy/speex_ubuntu.git people/ronynandy/linux_stable.git people/bhoj/boot-wrapper.git people/bhoj/test-manifest.git people/ycmiao/pxa-linux.git people/vireshk/module.git people/vireshk/linux-linaro-big-LITTLE-MP.git people/dooferlad/patchwork.git people/jessebarker/linaro-mm-sig/linux.git people/jessebarker/linaro-mm-sig/linux-2.6.git people/sachin-gupta/gstreamer.git people/stevejahnke/kernel-thermal-framework.git people/stevejahnke/thermal_manager.git people/pfefferz/manifest.git people/pfefferz/linux-2.6.git people/doanac/LinaroConnect.git people/doanac/monitis_python.git people/doanac/linaro-toolchain-benchmarking.git tools/arm-probe.git arm/big.LITTLE/mp.git ubuntu/linux-linaro-oneiric.git ubuntu/future-linux-linaro-precise-3.2.git ubuntu/linux-linaro-quantal.git ubuntu/linux-linaro-precise.git ubuntu/linux-meta-linaro-natty.git landing-teams/working/samsung/edk2-origen.git Thanks! -- Loïc Minier

12 years, 1 month

Making countless kernel reboots painless on TC2

by Nicolas Pitre

When working on low level kernel code, the indication that something went wrong is often noticed as a kernel oops, or even a totally silent system. This usually implies a modify-recompile-reboot cycle which can become very very annoying if the reboot step implies popping out an SD card from the board, inserting it into the work PC, mounting it, copying the newly compiled kernel over, unmounting, moving the SD card back to the board, to finally hit the reset button. If you are an old fashioned kernel developer like me and live by the simplest development environment (bash, vi, gcc) and your most trusted debugging tool is printk(), then having the ability to quickly boot a new kernel after moving printk traces around in order to pinpoint a crash location is vital. But even for validation purposes on a remote board, not needing physical intervention is really nice. So, by popular demand, here's how I accomplished this on VirtualExpress with a TC2 tile. This probably applies to other VirtualExpress configurations too, but TC2 is the only one I tested. Obtaining U-Boot ---------------- I don't have a particular affection for any bootloaders. They tend to ask for more and more attention and visibility while their raison d'être is actually to get out of the way and disappear as fast as possible. While U-Boot has many things that certainly gets on my nerves, it has a good point for itself which is its networking support. And here is the key: let's fetch everything we need to boot the board over the network, script it, so not to have to deal with the bootloader (or bootloaders in this case) anymore. First, let's get a copy of the U-Boot source tree. I used the Linaro version as it includes Versatile Express support. $ git clone git://git.linaro.org/boot/u-boot-linaro-stable.git $ cd u-boot-linaro-stable/ Now... to get rid of U-Boot's most obnoxious feature (my opinion), the following patch should be applied: diff --git a/include/configs/vexpress_common.h b/include/configs/vexpress_common.h index 88a2c95..3328443 100644 --- a/include/configs/vexpress_common.h +++ b/include/configs/vexpress_common.h @@ -177,6 +177,8 @@ #define CONFIG_CMD_SAVEENV #define CONFIG_CMD_RUN #define CONFIG_CMD_BOOTD +#define CONFIG_CMD_BOOTZ +#define CONFIG_SUPPORT_RAW_INITRD #define CONFIG_CMD_ECHO #define CONFIG_CMD_FAT That basically enables U-Boot to boot a plain ARM Linux zImage file without going through the mkimage step (the bootz command), and load a plain ramdisk image without having to run mkimage on it. This mkimage step is just extra fuss I can dispense with when working on and booting kernels frequently. Now let's build it. There is no TC2 (ca15 or ca7) config, however the ca5 one appears to be close enough for our needs: $ make vexpress_ca5x2 You should end up with a u-boot.bin to be used later. ARM Versatile Express Boot Monitor ---------------------------------- This is the native boot loader on the Virtual Express. In fact there are many instances of different loaders even on different processors making the whole system rather weird but flexible. It lacks the ability to load files from the network though. But that's what a second stage bootloader such as U-Boot is for. Good information on setting up a Virtual Express already exists. While the instructions listed therein may or may not all apply to our case, I still recommend to read the following pages to get familiar with this beast: https://wiki.linaro.org/PawelMoll/BootingVEMadeEasy The script to generate a boot script to generate an ATAGS block is a rather nice hack. But I want runtime DTB support and I prefer booting over the network, especially when playing with ramdisk images which is otherwise long to get reflashed. Still this page provides a nice introduction to Virtual Express setup and gives good insights on the micro switch usage and the VE boot monitor structure. https://wiki.linaro.org/ARM/VersatileExpressSetup This page shows how to install U-Boot on a Virtual Express and that's what we want here. you should follow the instructions listed for the CA15x2 CoreTile, except that the U-Boot binary to use is the one we just compiled above. Also, for TC2 the images.txt file is located in SITE1/HBI0249A/. In short, once the internal MicroSD card is mounted over USb, the u-boot.bin file we compiled should be copied to SOFTWARE/u-boot.bin. Then the file SITE1/HBI0249A/images.txt should be updated to contain something similar to this: NOR4UPDATE: AUTO NOR4ADDRESS: 0f800000 NOR4FILE: \SOFTWARE\u-boot.bin NOR4LOAD: 0x80800000 NOR4ENTRY: 0x80800000 We also need a boot script to start U-Boot automatically: NOR5UPDATE: AUTO NOR5NAME: BOOTSCRIPT NOR5ADDRESS: 00000000 NOR5FILE: \SOFTWARE\boot.txt Here the "BOOTSCRIPT" name is important otherwise the script won't be found and executed. The number after "NOR" may differ, depending on the other images your images.txt may already contain. Don't forget to update the TOTALIMAGES value at the top to reflect the number of image definitions you have, especially if you added new ones. Finally, the content of SOFTWARE/boot.txt only needs to contain one line: flash run u-boot That's it! unmounting the USB disk, setting SW[0] down and booting the main board (entering the "reboot" command on the serial console) should bring you to an U-Boot prompt. The U-Boot configuration ------------------------ Once at the U-Boot prompt, it is necessary to set a couple environment variables: VExpress# setenv bootcmd run loadbootscript\; source \$fileaddr VExpress# setenv loadbootscript dhcp 0x84000000 192.168.2.2:tc2_boot.scr VExpress# saveenv In the loadbootscript definition, I used an explicit IP address to prefix the file name. This is because my DHCP server is not the same machine as my TFTP server used to provide the location for the loaded files. If your DHCP configuration already provides that information then it is not necessary to provide such prefix. If you prefer using a fixed IP address for the board, you may simply set the ipaddr, netmask and gatewayip environment variables accordingly, and replace dhcp with tftp in the definition of loadbootscript. And don't forget to saveenv again. That's it! Once the script is loaded over the network, we don't need to deal with U-Boot's configuration anymore. The U-Boot boot script ---------------------- Now you need a TFTP server (normally tftpd) on your PC or laptop. In its content directory, there should be a file called tc2_boot.scr. Unfortunately, the U-Boot obnoxiousness is striking back at us since this must be mkimage wrapped. Let's start with the source, say tc2_boot.txt which should contain the following U-Boot commands: # set the TFTP server address (the dhcp command clobbers it) setenv serverip 192.168.2.2 # load a DTB tftp 0x82000000 vexpress-v2p-iks-tc2.dtb # tell U-Boot about it fdt addr $fileaddr # load a ramdisk image tftp 0x88000000 initrd.gz # remember its location and size for later setenv rd_addr $fileaddr setenv rd_size $filesize # load the kernel tftp 0x81000000 zImage # set our kernel parameters setenv bootargs console=ttyAMA0,38400 earlyprintk debug root=/dev/sda1 rootwait # boot the kernel bootz $fileaddr $rd_addr:$rd_size $fdtaddr The above is what I use and can be adapted to your needs. Again, maybe you don't need to override serverip. Maybe you wish to use a NFS root. Etc. That's the beauty of it: it is just a .txt file on your PC that you can modify at will without having to flash it anywhere. Temporary changes to the DTB with the fdt commands are also possible without having to modify and recompile the corresponding .dts, etc. However we need to ubootize it into tc2_boot.scr before it is usable: $ mkimage -A ARM -T script -C none -d tc2_boot.txt tc2_boot.scr (The one who tells me how to avoid this step gets a cookie.) Suffice to copy the desired kernel zImage and initrd files there too for the boot to proceed. It might even be possible to use a symbolic link towards the zImage produced by the compilation of the kernel directly so to avoid that copy, but I didn't push my own laziness that far. Let's boot! ----------- Now you may use the "reboot" command at the "Cmd>" prompt provided by the microcontroller to power up the board. When the board is booted, this prompt is moved from UART 0 to UART 1 while the kernel console output is going to UART 0, so it is possible to shutdown or reboot the board over UART 1 entirely unattended and remotely when both serial ports are connected to a computer. Enjoy ! Nicolas

12 years, 1 month

Linaro ubuntu Test Result Summary for 12.10 release (Calendar Week 43).

by Botao Sun

Linaro 12.10 Release (Calendar Week 43): Here is test result summary for Linaro ubuntu image on following boards: 1) ARM Versatile Express A9; 2) Samsung Origen; 3) TI Panda Board 4430; 4) TI Panda Board 4460. Synopsis: No change on feature status for vexpress A9 and Samsung Origen. Audio over HDMI and 3.5mm Jack Ports works well on another Panda 4430 board which is currently held by another colleague. Suspend / Resume works well on Panda 4460 but still failed on 4430. 1. vexpress A9 + ubuntu (Column AF): https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AroPySpr4FnEdFNmV… Features' status is exactly same as previous week. Device Tree is still unavailable and ARM landing team will continue their work on this. Video playback is unavailable either. 2. Origen + ubuntu (Column AA): https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AroPySpr4FnEdEowN… Now Power Management test doesn't hang the board, but still have many failed test result. WiFi, Bluetooth, Unity 3D, HDMI and Video Playback are still unavailable. 3. Panda 4430 + ubuntu (Column AC): https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AroPySpr4FnEdEwwZ… Audio over HDMI and 3.5mm Jack Ports works well on another Panda 4430 board, and this will lead us to consider more about the hardware issue. The other features remain the same. 4. Panda 4460 + ubuntu (Column AB): https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AroPySpr4FnEdEwwZ… Suspend / Resume now works well on this build, but the Power Management test popped up an old failure again. All other features remain the same, dead lock error is still in the boot log and Audio input over 3.5mm Jack Port is unavailable. For the previous week (Calendar week 42) summary, please refer to attachment. Thank you. Best Regards Botao Sun

12 years, 1 month

[PATCH 1/2] cpufreq: Improve debug prints

by Viresh Kumar

With debug options on, it is difficult to locate cpufreq core's debug prints. Fix this by prefixing debug prints with: "cpufreq: " Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org> --- drivers/cpufreq/cpufreq.c | 2 ++ drivers/cpufreq/cpufreq_performance.c | 2 ++ drivers/cpufreq/cpufreq_powersave.c | 2 ++ drivers/cpufreq/cpufreq_userspace.c | 2 ++ drivers/cpufreq/freq_table.c | 2 ++ 5 files changed, 10 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index db6e337..bcbc99d 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -15,6 +15,8 @@ * */ +#define pr_fmt(fmt) "cpufreq: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> diff --git a/drivers/cpufreq/cpufreq_performance.c b/drivers/cpufreq/cpufreq_performance.c index f13a8a9..67e3232 100644 --- a/drivers/cpufreq/cpufreq_performance.c +++ b/drivers/cpufreq/cpufreq_performance.c @@ -10,6 +10,8 @@ * */ +#define pr_fmt(fmt) "cpufreq: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/cpufreq.h> diff --git a/drivers/cpufreq/cpufreq_powersave.c b/drivers/cpufreq/cpufreq_powersave.c index 4c2eb51..eb974b6 100644 --- a/drivers/cpufreq/cpufreq_powersave.c +++ b/drivers/cpufreq/cpufreq_powersave.c @@ -10,6 +10,8 @@ * */ +#define pr_fmt(fmt) "cpufreq: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/cpufreq.h> diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c index bedac1a..6d7ccdb 100644 --- a/drivers/cpufreq/cpufreq_userspace.c +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -11,6 +11,8 @@ * */ +#define pr_fmt(fmt) "cpufreq: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/smp.h> diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c index 90431cb..246949c 100644 --- a/drivers/cpufreq/freq_table.c +++ b/drivers/cpufreq/freq_table.c @@ -9,6 +9,8 @@ * */ +#define pr_fmt(fmt) "cpufreq: " fmt + #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> -- 1.7.12.rc2.18.g61b472e

12 years, 1 month

[RFC] Energy/power monitoring within the kernel

by Pawel Moll

Greetings All, More and more of people are getting interested in the subject of power (energy) consumption monitoring. We have some external tools like "battery simulators", energy probes etc., but some targets can measure their power usage on their own. Traditionally such data should be exposed to the user via hwmon sysfs interface, and that's exactly what I did for "my" platform - I have a /sys/class/hwmon/hwmon*/device/energy*_input and this was good enough to draw pretty graphs in userspace. Everyone was happy... Now I am getting new requests to do more with this data. In particular I'm asked how to add such information to ftrace/perf output. The second most frequent request is about providing it to a "energy aware" cpufreq governor. I've came up with three (non-mutually exclusive) options. I will appreciate any other ideas and comments (including "it makes not sense whatsoever" ones, with justification). Of course I am more than willing to spend time on prototyping anything that seems reasonable and propose patches. === Option 1: Trace event === This seems to be the "cheapest" option. Simply defining a trace event that can be generated by a hwmon (or any other) driver makes the interesting data immediately available to any ftrace/perf user. Of course it doesn't really help with the cpufreq case, but seems to be a good place to start with. The question is how to define it... I've came up with two prototypes: = Generic hwmon trace event = This one allows any driver to generate a trace event whenever any "hwmon attribute" (measured value) gets updated. The rate at which the updates happen can be controlled by already existing "update_interval" attribute. 8<------------------------------------------- TRACE_EVENT(hwmon_attr_update, TP_PROTO(struct device *dev, struct attribute *attr, long long input), TP_ARGS(dev, attr, input), TP_STRUCT__entry( __string( dev, dev_name(dev)) __string( attr, attr->name) __field( long long, input) ), TP_fast_assign( __assign_str(dev, dev_name(dev)); __assign_str(attr, attr->name); __entry->input = input; ), TP_printk("%s %s %lld", __get_str(dev), __get_str(attr), __entry->input) ); 8<------------------------------------------- It generates such ftrace message: <...>212.673126: hwmon_attr_update: hwmon4 temp1_input 34361 One issue with this is that some external knowledge is required to relate a number to a processor core. Or maybe it's not an issue at all because it should be left for the user(space)? = CPU power/energy/temperature trace event = This one is designed to emphasize the relation between the measured value (whether it is energy, temperature or any other physical phenomena, really) and CPUs, so it is quite specific (too specific?) 8<------------------------------------------- TRACE_EVENT(cpus_environment, TP_PROTO(const struct cpumask *cpus, long long value, char unit), TP_ARGS(cpus, value, unit), TP_STRUCT__entry( __array( unsigned char, cpus, sizeof(struct cpumask)) __field( long long, value) __field( char, unit) ), TP_fast_assign( memcpy(__entry->cpus, cpus, sizeof(struct cpumask)); __entry->value = value; __entry->unit = unit; ), TP_printk("cpus %s %lld[%c]", __print_cpumask((struct cpumask *)__entry->cpus), __entry->value, __entry->unit) ); 8<------------------------------------------- And the equivalent ftrace message is: <...>127.063107: cpus_environment: cpus 0,1,2,3 34361[C] It's a cpumask, not just single cpu id, because the sensor may measure the value per set of CPUs, eg. a temperature of the whole silicon die (so all the cores) or an energy consumed by a subset of cores (this is my particular use case - two meters monitor a cluster of two processors and a cluster of three processors, all working as a SMP system). Of course the cpus __array could be actually a special __cpumask field type (I've just hacked the __print_cpumask so far). And I've just realised that the unit field should actually be a string to allow unit prefixes to be specified (the above should obviously be "34361[mC]" not "[C]"). Also - excuse the "cpus_environment" name - this was the best I was able to come up with at the time and I'm eager to accept any alternative suggestions :-) === Option 2: hwmon perf PMU === Although the trace event makes it possible to obtain interesting information using perf, the user wouldn't be able to treat the energy meter as a normal data source. In particular there would be no way of creating a group of events consisting eg. of a "normal" leader (eg. cache miss event) triggering energy meter read. The only way to get this done is to implement a perf PMU backend providing "environmental data" to the user. = High-level hwmon API and PMU = Current hwmon subsystem does not provide any abstraction for the measured values and requires particular drivers to create specified sysfs attributes than used by userspace libsensors. This makes the framework ultimately flexible and ultimately hard to access from within the kernel... What could be done here is some (simple) API to register the measured values with the hwmon core which would result in creating equivalent sysfs attributes automagically, but also allow a in-kernel API for values enumeration and access. That way the core could also register a "hwmon PMU" with the perf framework providing data from all "compliant" drivers. = A driver-specific PMU = Of course a particular driver could register its own perf PMU on its own. It's certainly an option, just very suboptimal in my opinion. Or maybe not? Maybe the task is so specialized that it makes sense? === Option 3: CPU power(energy) monitoring framework === And last but not least, maybe the problem deserves some dedicated API? Something that would take providers and feed their data into interested parties, in particular a perf PMU implementation and cpufreq governors? Maybe it could be an extension to the thermal framework? It already gives some meaning to a physical phenomena. Adding other, related ones like energy, and relating it to cpu cores could make some sense. I've tried to gather all potentially interested audience in the To: list, but if I missed anyone - please, do let them (and/or me) know. Best regards and thanks for participation in the discussion! Pawel

12 years, 1 month

TC2s offline

by Dave Pigott

Hi All, Due to a glitch with UEFI and the latest kernels, we are forced to leave the TC2s offline until the issue is resolved. Ryan Harkin and I have been working to try and resolve this, but the best we could do is to get them to pass their health check (using sticking plaster, string and a large hammer) but they would then fail every test that was submitted to them, which would be kind of pointless. We're working actively to fix this problem, and I'll let you know when we're back up and running. Thanks, and apologies once again, Dave

12 years, 1 month

Re: drivers/cpufreq/cpufreq_governor.c:46:53: sparse: incorrect type in argument 2 (different modifiers)

by Viresh Kumar

Hi Fengguang, Thanks for your mail. Few things i learnt from it: - Rafael has already applied my patches :) - I haven't used sparse in my life till this point. Now i know how to use it. On 23 October 2012 10:21, Fengguang Wu <fengguang.wu(a)intel.com> wrote: > Hi viresh, > > FYI, there are new sparse warnings show up in Actually these aren't new warnings, but old. Because some part is moved from one file to another, that's why your script shows them as new warnings. Anyway, i don't hesitate in fixing them. @Rafael: Most of these are due to mixed use of u64 and cputime64_t. Both of which are u64 if i am not wrong. Any specific reason that we used cputime64_t instead of u64? Or can i make everything u64 instead in governors? -- viresh > tree: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next > head: 13f5e2d9a915373dd1573d8fe0214738bc69004f > commit: 83a73f712f2275033b2dc7f5c664988a1823ebc7 cpufreq: Move common part from governors to separate file, v2 > date: 5 hours ago > > + drivers/cpufreq/cpufreq_governor.c:46:53: sparse: incorrect type in argument 2 (different modifiers) > drivers/cpufreq/cpufreq_governor.c:46:53: expected unsigned long long [usertype] *wall > drivers/cpufreq/cpufreq_governor.c:46:53: got unsigned long long [nocast] [usertype] *wall > + drivers/cpufreq/cpufreq_governor.c:46:53: sparse: implicit cast from nocast type > drivers/cpufreq/cpufreq_governor.c:48:58: sparse: incorrect type in argument 2 (different modifiers) > drivers/cpufreq/cpufreq_governor.c:48:58: expected unsigned long long [usertype] *last_update_time > drivers/cpufreq/cpufreq_governor.c:48:58: got unsigned long long [nocast] [usertype] *wall > drivers/cpufreq/cpufreq_governor.c:48:58: sparse: implicit cast from nocast type > > vim +46 drivers/cpufreq/cpufreq_governor.c > > 83a73f71 viresh kumar 2012-10-23 30 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; > 83a73f71 viresh kumar 2012-10-23 31 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; > 83a73f71 viresh kumar 2012-10-23 32 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; > 83a73f71 viresh kumar 2012-10-23 33 > 83a73f71 viresh kumar 2012-10-23 34 idle_time = cur_wall_time - busy_time; > 83a73f71 viresh kumar 2012-10-23 35 if (wall) > 83a73f71 viresh kumar 2012-10-23 36 *wall = jiffies_to_usecs(cur_wall_time); > 83a73f71 viresh kumar 2012-10-23 37 > 83a73f71 viresh kumar 2012-10-23 38 return jiffies_to_usecs(idle_time); > 83a73f71 viresh kumar 2012-10-23 39 } > 83a73f71 viresh kumar 2012-10-23 40 > 83a73f71 viresh kumar 2012-10-23 41 cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) > 83a73f71 viresh kumar 2012-10-23 42 { > 83a73f71 viresh kumar 2012-10-23 43 u64 idle_time = get_cpu_idle_time_us(cpu, NULL); > 83a73f71 viresh kumar 2012-10-23 44 > 83a73f71 viresh kumar 2012-10-23 45 if (idle_time == -1ULL) > 83a73f71 viresh kumar 2012-10-23 @46 return get_cpu_idle_time_jiffy(cpu, wall); > 83a73f71 viresh kumar 2012-10-23 47 else > 83a73f71 viresh kumar 2012-10-23 48 idle_time += get_cpu_iowait_time_us(cpu, wall); > 83a73f71 viresh kumar 2012-10-23 49 > 83a73f71 viresh kumar 2012-10-23 50 return idle_time; > 83a73f71 viresh kumar 2012-10-23 51 } > 83a73f71 viresh kumar 2012-10-23 52 EXPORT_SYMBOL_GPL(get_cpu_idle_time); > > --- > 0-DAY kernel build testing backend Open Source Technology Center > Fengguang Wu, Yuanhan Liu Intel Corporation

12 years, 1 month

[RFC PATCH 00/10] sched: Task placement for heterogeneous MP systems

by morten.rasmussen＠arm.com

From: Morten Rasmussen <morten.rasmussen(a)arm.com> Hi Paul, Paul, Peter, Suresh, linaro-sched-sig, and LKML, As a follow-up on my Linux Plumbers Conference talk about my experiments with scheduling on heterogeneous systems I'm posting a proof-of-concept patch set with my modifications. The intention behind the modifications is to tweak scheduling behaviour to only use fast (and power hungry) cores when it is necessary and also improve performance consistency. Without the modifications it is more or less random where tasks are scheduled and so is the execution time. I'm seeing good improvements on performance consistency for web browsing on Android using Bbench <http://www.gem5.org/Bbench> on the ARM big.LITTLE TC2 chip, which has two fast cores (Cortex-A15) and three power-efficient cores (Cortex-A7). The total execution time numbers below are for Androids SurfaceFlinger process is key for page rendering performance. The average execution time is lower with the patches enabled and the standard deviation is much smaller. Similar improvements can be seen for the Android.Browser and WebViewCoreThread processes. Total execution time statistics based on 50 runs. SurfaceFlinger SMP kernel [s] HMP modifications [s] ------------------------------------------------------ Average 14.617 11.012 St. Dev. 4.577 0.902 10% Pctl. 9.343 10.783 90% Pctl. 18.743 11.695 Unfortunately, I cannot share power-efficiency numbers at this stage. This patch set introduces proof-of-concept scheduler modifications which attempt to improve scheduling decisions on heterogeneous multi-processor systems (HMP) such as ARM big.LITTLE systems. The patch set relies on the entity load-tracking re-work patch set by Paul Turner: <https://lkml.org/lkml/2012/8/23/267> The modifications attempt to migrate tasks between cores with different compute capacity depending on the tracked load and priority. The aim is to only use fast cores for tasks which really need the extra performance and thereby improve power consumption by running everything else on the slow cores. The patch introduces hmp_domains to represent the different types of cores that are available on the given platform. Multiple (>2) hmp_domains is supported but not tested. hmp_domains must be set up by platform code and the patch set includes patches for ARM platforms using device-tree. The patches intentionally try to avoid modifying the existing code paths as much as possible. The aim is to experiment with HMP scheduling and get the overall policy right before integrating it properly with the existing load-balancer. Morten Morten Rasmussen (10): sched: entity load-tracking load_avg_ratio sched: Task placement for heterogeneous systems based on task load-tracking sched: Forced task migration on heterogeneous systems sched: Introduce priority-based task migration filter ARM: Add HMP scheduling support for ARM architecture ARM: sched: Use device-tree to provide fast/slow CPU list for HMP ARM: sched: Setup SCHED_HMP domains sched: Add ftrace events for entity load-tracking sched: Add HMP task migration ftrace event sched: SCHED_HMP multi-domain task migration control arch/arm/Kconfig | 46 +++++ arch/arm/include/asm/topology.h | 32 +++ arch/arm/kernel/topology.c | 91 ++++++++ include/linux/sched.h | 11 + include/trace/events/sched.h | 153 ++++++++++++++ kernel/sched/core.c | 4 + kernel/sched/fair.c | 434 ++++++++++++++++++++++++++++++++++++++- kernel/sched/sched.h | 9 + 8 files changed, 779 insertions(+), 1 deletion(-) -- 1.7.9.5

12 years, 1 month

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linaro-dev October 2012