[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Changed in: linux (Ubuntu) Status: In Progress => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
This bug was fixed in the package linux - 3.19.0-23.24
---
linux (3.19.0-23.24) vivid; urgency=low
[ Luis Henriques ]
* Release Tracking Bug
- LP: #1472346
[ Chris J Arges ]
* SAUCE: Don't use atomic read in evlist.c
- LP: #1410673
linux (3.19.0-23.23) vivid; urgency=low
[ Brad Figg ]
* Release Tracking Bug
- LP: #1472048
[ Chris J Arges ]
* [Config] Add CRYPTO_DEV_NX_*, 842_* as modules
- LP: #1454687
[ Lu, Han ]
* SAUCE: i915_bpo: drm/i915/audio: add codec wakeup override
enabled/disable callback
- LP: #1460674
[ Timo Aaltonen ]
* SAUCE: Backport I915_OVERLAY_DISABLE_DEST_COLORKEY
- LP: #1460674
* SAUCE: i915_bpo: Rebase to drm-intel-next-fixes-2015-05-29
- LP: #1460674
* SAUCE: i915_bpo: Revert drm/i915: Implement the intel_dp_autotest_edid
function for DP EDID complaince tests
- LP: #1460674
* SAUCE: i915_bpo: Revert drm/i915: Add debugfs test control files for
Displayport compliance testing
- LP: #1460674
* SAUCE: Load i915_bpo from the hda driver on SKL/CHV
- LP: #1460674
* SAUCE: i915_bpo: Don't try to support BXT
- LP: #1460674
* SAUCE: i915_bpo: drm/i915/skl: Fix DMC API version.
[ Upstream Kernel Changes ]
* Revert usb: dwc2: add bus suspend/resume for dwc2
- LP: #1471252
* Revert HID: logitech-hidpp: support combo keyboard touchpad TK820
- LP: #1471252
* Revert KVM: x86: drop fpu_activate hook
- LP: #1471252
* Revert libceph: clear r_req_lru_item in __unregister_linger_request()
- LP: #1471252
* drm/i915: add component support
- LP: #1460661
* ALSA: hda: export struct hda_intel
- LP: #1460661
* ALSA: hda: pass intel_hda to all i915 interface functions
- LP: #1460661
* ALSA: hda: add component support
- LP: #1460661
* drm/atomic-helpers: Fix documentation typos and wrong copypaste
- LP: #1460674
* drm/atomic: Rename drm_atomic_helper_commit_pre_planes() state argument
- LP: #1460674
* drm/atomic-helper: Rename commmit_post/pre_planes
- LP: #1460674
* drm/atomic-helpers: make mode_set hooks optional
- LP: #1460674
* drm/atomic-helper: Fix kerneldoc for prepare_planes
- LP: #1460674
* drm: Complete moving rotation property to core
- LP: #1460674
* drm: Share plane pixel format check code between legacy and atomic
- LP: #1460674
* drm/atomic: Constify a bunch of functions pointer structs
- LP: #1460674
* drm: Fix some typo mistake of the annotations
- LP: #1460674
* drm: change connector to tmp_connector
- LP: #1460674
* drm: atomic: Expose CRTC active property
- LP: #1460674
* drm: atomic: Allow setting CRTC active property
- LP: #1460674
* drm/atomic-helpers: Properly avoid full modeset dance
- LP: #1460674
* drm/atomic: Add helpers for state-subclassing drivers
- LP: #1460674
* drm: Fix some typos
- LP: #1460674
* drm/atomic: Add for_each_{connector,crtc,plane}_in_state helper macros
- LP: #1460674
* drm/atomic-helper: Don't call atomic_update_plane when it stays off
- LP: #1460674
* drm/atomic-helper: Really recover pre-atomic plane/cursor behavior
- LP: #1460674
* drm/atomic: Make mode_fixup() optional for check_modeset()
- LP: #1460674
* drm/atomic-helpers: Update vblank timestamping constants
- LP: #1460674
* drm/atomic-helpers: Export
drm_atomic_helper_update_legacy_modeset_state
- LP: #1460674
* drm/atomic: add drm_atomic_get_existing_*_state helpers
- LP: #1460674
* drm/atomic: remove duplicated assignment of old_plane_state
- LP: #1460674
* drm/atomic: Allow drivers to subclass drm_atomic_state, v3
- LP: #1460674
* drm/dp: indentation and ordering cleanups
- LP: #1460674
* drm/dp: add DPCD definitions from eDP 1.2
- LP: #1460674
* drm/dp: add DPCD definitions from DP 1.1 and 1.2a
- LP: #1460674
* drm/dp: add DPCD definitions from eDP 1.4
- LP: #1460674
* drm: Adding drm helper function drm_plane_from_index().
- LP: #1460674
* ALSA: hda - reset display codec when power on
- LP: #1460674
* drm/i915/audio: add codec wakeup override enabled/disable callback
- LP: #1460674
* scsi: storvsc: Increase the ring buffer size
- LP: #1445195
* scsi: storvsc: Size the queue depth based on the ringbuffer size
- LP: #1445195
* scsi: storvsc: Always send on the selected outgoing channel
- LP: #1445195
* scsi: storvsc: Retrieve information about the capability of the target
- LP: #1445195
* scsi: storvsc: Don't assume that the scatterlist is not chained
- LP: #1445195
* scsi: storvsc: Set the tablesize based on the information given by the
host
- LP: #1445195
* Drivers: hv: vmbus: Add support for VMBus panic notifier handler
- LP: #1463584
* Drivers: hv: vmbus: Correcting truncation error for constant
HV_CRASH_CTL_CRASH_NOTIFY
- LP: #1463584
* net: eth: xgene: change APM X-Gene SoC platform
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
This bug was fixed in the package linux - 3.16.0-44.59 --- linux (3.16.0-44.59) utopic; urgency=low [ Brad Figg ] * Release Tracking Bug - LP: #1472030 [ Iyappan Subramanian ] * SAUCE: (no-up) drivers: net: xgene: fix: Out of order descriptor bytes read - LP: #1425576 [ Upstream Kernel Changes ] * Revert tools/vm: fix page-flags build - LP: #1471170 * NVMe: Add shutdown timeout as module parameter. - LP: #1465136 * Drivers: hv: vmbus: Add support for VMBus panic notifier handler - LP: #1463584 * Drivers: hv: vmbus: Correcting truncation error for constant HV_CRASH_CTL_CRASH_NOTIFY - LP: #1463584 * KVM: nVMX: fix lifetime issues for vmcs02 - LP: #1448269 * KVM: nVMX: Fix nested vmexit ack intr before load vmcs01 - LP: #1448269 * mm/slab_common: support the slub_debug boot option on specific object size - LP: #1456952 * kvm: x86: fix kvm_apic_has_events to check for NULL pointer * cpuidle: powernv: Populate cpuidle state details by querying the device-tree - LP: #1470404 * cpuidle: powernv: Read target_residency value of idle states from DT if available - LP: #1470404 * cpuidle: powernv: Avoid endianness conversions while parsing DT - LP: #1470404 * cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state - LP: #1470404 * iio: adis16400: Report pressure channel scale - LP: #1471170 * iio: adis16400: Use != channel indices for the two voltage channels - LP: #1471170 * iio: adis16400: Compute the scan mask from channel indices - LP: #1471170 * iio: adis16400: Remove unused variable - LP: #1471170 * iio: adis16400: Fix burst mode - LP: #1471170 * iio: adis16400: Fix burst transfer for adis16448 - LP: #1471170 * USB: serial: ftdi_sio: Add support for a Motion Tracker Development Board - LP: #1471170 * iio: adc: twl6030-gpadc: Fix modalias - LP: #1471170 * serial: imx: Fix DMA handling for IDLE condition aborts - LP: #1471170 * usb: dwc3: gadget: Fix incorrect DEPCMD and DGCMD status macros - LP: #1471170 * ALSA: usb-audio: Add mic volume fix quirk for Logitech Quickcam Fusion - LP: #1471170 * n_tty: Fix auditing support for cannonical mode - LP: #1471170 * drm/i915/hsw: Fix workaround for server AUX channel clock divisor - LP: #1471170 * x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers - LP: #1471170 * lib: Fix strnlen_user() to not touch memory after specified maximum - LP: #1471170 * Input: elantech - fix detection of touchpads where the revision matches a known rate - LP: #1471170 * ALSA: hda/realtek - Add a fixup for another Acer Aspire 9420 - LP: #1471170 * ALSA: usb-audio: add MAYA44 USB+ mixer control names - LP: #1471170 * ALSA: usb-audio: fix missing input volume controls in MAYA44 USB(+) - LP: #1471170 * USB: cp210x: add ID for HubZ dual ZigBee and Z-Wave dongle - LP: #1471170 * Input: elantech - add new icbody type - LP: #1471170 * MIPS: Fix enabling of DEBUG_STACKOVERFLOW - LP: #1471170 * xfrm: fix a race in xfrm_state_lookup_byspi - LP: #1471170 * kconfig: Fix warning ‘jump’ may be used uninitialized - LP: #1471170 * scripts/sortextable: suppress warning: `relocs_size' may be used uninitialized - LP: #1471170 * thermal: step_wise: Revert optimization - LP: #1471170 * MIPS: KVM: Do not sign extend on unsigned MMIO load - LP: #1471170 * arch/x86/kvm/mmu.c: work around gcc-4.4.4 bug - LP: #1471170 * net: core: Correct an over-stringent device loop detection. - LP: #1471170 * net: phy: Allow EEE for all RGMII variants - LP: #1471170 * net: dp83640: fix broken calibration routine. - LP: #1471170 * net: dp83640: reinforce locking rules. - LP: #1471170 * unix/caif: sk_socket can disappear when state is unlocked - LP: #1471170 * xen/netback: Properly initialize credit_bytes - LP: #1471170 * udp: fix behavior of wrong checksums - LP: #1471170 * xen: netback: read hotplug script once at start of day. - LP: #1471170 * ipv4/udp: Verify multicast group is ours in upd_v4_early_demux() - LP: #1471170 * bridge: disable softirqs around br_fdb_update to avoid lockup - LP: #1471170 * drm/i915: Assume dual channel LVDS if pixel clock necessitates it - LP: #1471170 * Btrfs: send, add missing check for dead clone root - LP: #1471170 * Btrfs: send, don't leave without decrementing clone root's send_progress - LP: #1471170 * btrfs: incorrect handling for fiemap_fill_next_extent return - LP: #1471170 * btrfs: cleanup orphans while looking up default subvolume - LP: #1471170 * iommu/vt-d: Allow RMRR on graphics devices too - LP: #1471170 * iommu/vt-d: Fix passthrough mode with translation-disabled devices - LP: #1471170 * ata: ahci_mvebu: Fix wrongly set base address for the MBus
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Changed in: linux (Ubuntu) Status: Triaged = In Progress -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Tags removed: verification-needed-utopic verification-needed-vivid ** Tags added: verification-done-utopic verification-done-vivid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- vivid' to 'verification-done-vivid'. If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- utopic' to 'verification-done-utopic'. If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-utopic ** Tags added: verification-needed-vivid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Changed in: linux (Ubuntu) Importance: Undecided = Medium ** Changed in: linux (Ubuntu) Status: Confirmed = Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
Sent SRU to Ubuntu kernel team ML for Utopic/Vivid. ** Description changed: SRU Justification: [Impact] Certain workloads can exhibit a large variance in behavior due to how how cpus are idled on power8 systems. [Fix] For 3.16: 74aa51b5ccd3975392e30d11820dc073c5f2cd32 92c83ff5b42b109c94fdeee53cb31f674f776d75 70734a786acfd1998e47d40df19cba5c29469bdf For 3.16, 3.19: 78eaa10f027cf69f9bd409e64eaff902172b2327 + + $ git describe 78eaa10f027cf69f9bd409e64eaff902172b2327 + v4.1-rc2-9-g78eaa10 + Once we rebase to something v4.1+ we'll have this fixed in Wily. [Test Case] Set the system with the SMT8 mode and scaling_governor=performance or ondemand. Run the workload 100 times. -- == Comment: #0 - Peter W. Wong wpe...@us.ibm.com - 2015-04-15 21:30:31 == ---Problem Description--- Many workloads experience wide measurement variation, more with scaling_governor=performance than ondemand. Contact Information = wpe...@us.ibm.com, fa...@us.ibm.com ---uname output--- Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux Machine Type = 20-core and 24-core Tuleta systems ---Debugger--- A debugger is not configured ---Steps to Reproduce--- Set the system with the SMT8 mode and scaling_governor=performance or ondemand. Run the workload 100 times. Get 100 data points and sort them. Compare the spread of results with two governor modes. The source and scripts to run a simple test case will be provided. Stack trace output: no Oops output: no Userspace tool common name: not sure what it is. Userspace rpm: ?? The userspace tool has the following bit modes: These are 64-bit programs. System Dump Info: The system is not configured to capture a system dump. Userspace tool obtained from project website: na *Additional Instructions for wpe...@us.ibm.com, fa...@us.ibm.com: -Attach sysctl -a output output to the bug. -Attach ltrace and strace of userspace application. == Comment: #2 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:47:41 == This problem has a number of variables we were trying to reduce: - endianness - operating system - kernel level - compiler Bob Walkup says he's seen the variability in a bunch of CPU-intensive test cases, in various languages, using various compilers, which would seem to eliminate the compiler variable. We had not looked at the performance governor setting to this point. Interesting results, and yet another variable to add to the above mix. Perhaps two more runs? (LE-ondemand, LE-performance, BE-ondemand, BE- performance) == Comment: #3 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:50:09 == Also, Bob says he can reproduce this with and without vectorization (the stalls move from the VSU to the FPU), and with and without floating point (the stalls move from the FPU to the FXU). Very odd. == Comment: #4 - Andrea M. Davis amda...@us.ibm.com - 2015-04-16 10:10:01 == Peter, what version of Ubuntu are you running? == Comment: #5 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:32:58 == Andrea, Ubuntu 14.04.2 LTS. #uname -a Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux #lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.2 LTS Release: 14.04 Codename: trusty == Comment: #6 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:50:11 == There are a few more things we have tried. (1) For STREAM, it was originally compiled with gfotran and its corresponding OpenMP. I compiled it with xlf and its corresponding OpenMP. There is no difference in performance. (2) There was a concern about NUMA, meaning is it possible the CPU binding by OpenMP is incorrect so that there are remote memory accesses behind the scene? By disabling one DCM and using 10 or 12 cores only in the other DCM, we can still see occasional drops in performance, although not often. We can conclude it is not due to NUMA. (3) Farid and I also tried out different scheduler parameters (sched_min_granularity_ns, sched_wakeup_granularity_ns, sched_latency_ns, and others) and matched the correponding the other distro's values, but did not see performance changes. (4) For the workload AMG2006, the use of scaling_performance=ondemand also reduces the spread of data significantly. (5) For all the above investigations, I used a 20-core Tuleta and a 24-core Tuleta, although they are configured identically with Ubuntu 14.04.2. I mean two systems paint a consistent picture. So far, we looked at compiler, NUMA, scheduler, memory test, CPU test, ST vs SMT, etc. There is a significant difference in variation between scaling_governor=performance and
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Description changed: SRU Justification: [Impact] - Certain workloads can exhibit a large variance in behavior due to how how cpus are idled on power8 systems. + Certain workloads can exhibit a large variance in behavior due to how how cpus are idled on power8 systems. [Fix] - 92c83ff5b42b109c94fdeee53cb31f674f776d75 (for 3.16) - 78eaa10f027cf69f9bd409e64eaff902172b2327 (for 3.16, 3.19) + + For 3.16: + 74aa51b5ccd3975392e30d11820dc073c5f2cd32 + 92c83ff5b42b109c94fdeee53cb31f674f776d75 + 70734a786acfd1998e47d40df19cba5c29469bdf + + For 3.16, 3.19: + 78eaa10f027cf69f9bd409e64eaff902172b2327 [Test Case] Set the system with the SMT8 mode and scaling_governor=performance or ondemand. Run the workload 100 times. -- == Comment: #0 - Peter W. Wong wpe...@us.ibm.com - 2015-04-15 21:30:31 == ---Problem Description--- Many workloads experience wide measurement variation, more with scaling_governor=performance than ondemand. Contact Information = wpe...@us.ibm.com, fa...@us.ibm.com ---uname output--- Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux Machine Type = 20-core and 24-core Tuleta systems ---Debugger--- A debugger is not configured ---Steps to Reproduce--- Set the system with the SMT8 mode and scaling_governor=performance or ondemand. Run the workload 100 times. Get 100 data points and sort them. Compare the spread of results with two governor modes. The source and scripts to run a simple test case will be provided. Stack trace output: no Oops output: no Userspace tool common name: not sure what it is. Userspace rpm: ?? The userspace tool has the following bit modes: These are 64-bit programs. System Dump Info: The system is not configured to capture a system dump. Userspace tool obtained from project website: na *Additional Instructions for wpe...@us.ibm.com, fa...@us.ibm.com: -Attach sysctl -a output output to the bug. -Attach ltrace and strace of userspace application. == Comment: #2 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:47:41 == This problem has a number of variables we were trying to reduce: - endianness - operating system - kernel level - compiler Bob Walkup says he's seen the variability in a bunch of CPU-intensive test cases, in various languages, using various compilers, which would seem to eliminate the compiler variable. We had not looked at the performance governor setting to this point. Interesting results, and yet another variable to add to the above mix. Perhaps two more runs? (LE-ondemand, LE-performance, BE-ondemand, BE- performance) == Comment: #3 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:50:09 == Also, Bob says he can reproduce this with and without vectorization (the stalls move from the VSU to the FPU), and with and without floating point (the stalls move from the FPU to the FXU). Very odd. == Comment: #4 - Andrea M. Davis amda...@us.ibm.com - 2015-04-16 10:10:01 == Peter, what version of Ubuntu are you running? == Comment: #5 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:32:58 == Andrea, Ubuntu 14.04.2 LTS. #uname -a Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux #lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.2 LTS Release: 14.04 Codename: trusty == Comment: #6 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:50:11 == There are a few more things we have tried. (1) For STREAM, it was originally compiled with gfotran and its corresponding OpenMP. I compiled it with xlf and its corresponding OpenMP. There is no difference in performance. (2) There was a concern about NUMA, meaning is it possible the CPU binding by OpenMP is incorrect so that there are remote memory accesses behind the scene? By disabling one DCM and using 10 or 12 cores only in the other DCM, we can still see occasional drops in performance, although not often. We can conclude it is not due to NUMA. (3) Farid and I also tried out different scheduler parameters (sched_min_granularity_ns, sched_wakeup_granularity_ns, sched_latency_ns, and others) and matched the correponding the other distro's values, but did not see performance changes. (4) For the workload AMG2006, the use of scaling_performance=ondemand also reduces the spread of data significantly. (5) For all the above investigations, I used a 20-core Tuleta and a 24-core Tuleta, although they are configured identically with Ubuntu 14.04.2. I mean two systems paint a consistent picture. So far, we looked at compiler, NUMA, scheduler, memory test, CPU test, ST vs SMT, etc. There is a significant difference in variation between
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Changed in: linux (Ubuntu Utopic) Status: In Progress = Fix Committed ** Changed in: linux (Ubuntu Vivid) Status: In Progress = Fix Committed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Package changed: ubuntu = linux (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode. To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1470404/+editstatus and add the package name in the text box next to the word Package. [This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.] ** Tags added: bot-comment -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
Hi, Is 78eaa10f027cf69f9bd409e64eaff902172b2327 alone sufficient to solve this issue, or are any other patches required? Thanks, --chris -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
The last question was for both 3.16 and 3.19. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1470404 Title: Some workloads experience more measurement variation with scaling_governor=performance than ondemand To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1470404/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1470404] Re: Some workloads experience more measurement variation with scaling_governor=performance than ondemand
** Also affects: linux (Ubuntu Vivid) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Utopic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu) Status: New = Confirmed ** Changed in: linux (Ubuntu Utopic) Status: New = In Progress ** Changed in: linux (Ubuntu Vivid) Status: New = In Progress ** Changed in: linux (Ubuntu Utopic) Importance: Undecided = Medium ** Changed in: linux (Ubuntu Vivid) Importance: Undecided = Medium ** Changed in: linux (Ubuntu Utopic) Assignee: (unassigned) = Chris J Arges (arges) ** Changed in: linux (Ubuntu Vivid) Assignee: (unassigned) = Chris J Arges (arges) ** Description changed: + SRU Justification: + [Impact] + Certain workloads can exhibit a large variance in behavior due to how how cpus are idled on power8 systems. + + [Fix] + 92c83ff5b42b109c94fdeee53cb31f674f776d75 (for 3.16) + 78eaa10f027cf69f9bd409e64eaff902172b2327 (for 3.16, 3.19) + + [Test Case] + Set the system with the SMT8 mode and scaling_governor=performance or ondemand. + Run the workload 100 times. + + -- + == Comment: #0 - Peter W. Wong wpe...@us.ibm.com - 2015-04-15 21:30:31 == ---Problem Description--- - Many workloads experience wide measurement variation, more with scaling_governor=performance than ondemand. - - Contact Information = wpe...@us.ibm.com, fa...@us.ibm.com - + Many workloads experience wide measurement variation, more with scaling_governor=performance than ondemand. + + Contact Information = wpe...@us.ibm.com, fa...@us.ibm.com + ---uname output--- Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux - - Machine Type = 20-core and 24-core Tuleta systems - + + Machine Type = 20-core and 24-core Tuleta systems + ---Debugger--- A debugger is not configured - + ---Steps to Reproduce--- Set the system with the SMT8 mode and scaling_governor=performance or ondemand. Run the workload 100 times. Get 100 data points and sort them. Compare the spread of results with two governor modes. The source and scripts to run a simple test case will be provided. - + Stack trace output: - no - + no + Oops output: - no - - Userspace tool common name: not sure what it is. - - Userspace rpm: ?? - - The userspace tool has the following bit modes: These are 64-bit programs. - + no + + Userspace tool common name: not sure what it is. + + Userspace rpm: ?? + + The userspace tool has the following bit modes: These are 64-bit + programs. + System Dump Info: - The system is not configured to capture a system dump. - - Userspace tool obtained from project website: na - - *Additional Instructions for wpe...@us.ibm.com, fa...@us.ibm.com: + The system is not configured to capture a system dump. + + Userspace tool obtained from project website: na + + *Additional Instructions for wpe...@us.ibm.com, fa...@us.ibm.com: -Attach sysctl -a output output to the bug. -Attach ltrace and strace of userspace application. == Comment: #2 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:47:41 == This problem has a number of variables we were trying to reduce: - endianness - operating system - kernel level - compiler Bob Walkup says he's seen the variability in a bunch of CPU-intensive test cases, in various languages, using various compilers, which would seem to eliminate the compiler variable. We had not looked at the performance governor setting to this point. Interesting results, and yet another variable to add to the above mix. Perhaps two more runs? (LE-ondemand, LE-performance, BE-ondemand, BE- performance) == Comment: #3 - Paul A. Clarke pac...@us.ibm.com - 2015-04-16 08:50:09 == Also, Bob says he can reproduce this with and without vectorization (the stalls move from the VSU to the FPU), and with and without floating point (the stalls move from the FPU to the FXU). Very odd. == Comment: #4 - Andrea M. Davis amda...@us.ibm.com - 2015-04-16 10:10:01 == Peter, what version of Ubuntu are you running? == Comment: #5 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:32:58 == Andrea, Ubuntu 14.04.2 LTS. #uname -a Linux c656f7n04 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:42:36 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux #lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.2 LTS Release: 14.04 Codename: trusty == Comment: #6 - Peter W. Wong wpe...@us.ibm.com - 2015-04-16 10:50:11 == There are a few more things we have tried. (1) For STREAM, it was originally compiled with gfotran and its corresponding OpenMP. I compiled it with xlf and its corresponding OpenMP. There is no difference in performance. (2) There was a concern about NUMA, meaning is it possible the CPU binding by OpenMP is incorrect so
