user/sven/linux.git/kernel/locking/locktorture.c, branch v5.4.43

locktorture: Print ratio of acquisitions, not failures

2020-04-23T08:36:44Z

commit 80c503e0e68fbe271680ab48f0fe29bc034b01b7 upstream. The __torture_print_stats() function in locktorture.c carefully initializes local variable "min" to statp[0].n_lock_acquired, but then compares it to statp[i].n_lock_fail. Given that the .n_lock_fail field should normally be zero, and given the initialization, it seems reasonable to display the maximum and minimum number acquisitions instead of miscomputing the maximum and minimum number of failures. This commit therefore switches from failures to acquisitions. And this turns out to be not only a day-zero bug, but entirely my own fault. I hate it when that happens! Fixes: 0af3fe1efa53 ("locktorture: Add a lock-torture kernel module") Reported-by: Will Deacon Signed-off-by: Paul E. McKenney Acked-by: Will Deacon Cc: Davidlohr Bueso Cc: Josh Triplett Cc: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman

torture: Allow inter-stutter interval to be specified

2019-05-28T16:06:09Z

Currently, the inter-stutter interval is the same as the stutter duration, that is, whatever number of jiffies is passed into torture_stutter_init(). This has worked well for quite some time, but the addition of forward-progress testing to rcutorture can delay processes for several seconds, which can triple the time that they are stuttered. This commit therefore adds a second argument to torture_stutter_init() that specifies the inter-stutter interval. While locktorture preserves the current behavior, rcutorture uses the RCU CPU stall warning interval to provide a wider inter-stutter interval. Signed-off-by: Paul E. McKenney

locktorture: NULL cxt.lwsa and cxt.lrsa to allow bad-arg detection

2019-03-26T21:42:53Z

Currently, lock_torture_cleanup() uses the values of cxt.lwsa and cxt.lrsa to detect bad parameters that prevented locktorture from initializing, let alone running. In this case, lock_torture_cleanup() does no cleanup aside from invoking torture_cleanup_begin() and torture_cleanup_end(), as required to permit future torture tests to run. However, this heuristic fails if the run with bad parameters was preceded by a previous run that actually ran: In this case, both cxt.lwsa and cxt.lrsa will remain non-zero, which means that the current lock_torture_cleanup() invocation will be unable to detect the fact that it should skip cleanup, which can result in charming outcomes such as double frees. This commit therefore NULLs out both cxt.lwsa and cxt.lrsa at the end of any run that actually ran. Signed-off-by: Paul E. McKenney Cc: Davidlohr Bueso Cc: Josh Triplett

Merge branches 'doc.2019.01.26a', 'fixes.2019.01.26a', 'sil.2019.01.26a', 'spdx.2019.02.09a', 'srcu.2019.01.26a' and 'torture.2019.01.26a' into HEAD

2019-02-09T16:47:52Z

doc.2019.01.26a: Documentation updates. fixes.2019.01.26a: Miscellaneous fixes. sil.2019.01.26a: Removal of a few more spin_is_locked() instances. spdx.2019.02.09a: Add SPDX identifiers to RCU files srcu.2019.01.26a: SRCU updates. torture.2019.01.26a: Torture-test updates.

locking/locktorture: Convert to SPDX license identifier

2019-02-09T16:46:37Z

Replace the license boiler plate with a SPDX license identifier. While in the area, update an email address. Signed-off-by: Paul E. McKenney Reviewed-by: Thomas Gleixner

rcutorture: Add grace period after CPU offline

2019-01-25T23:37:10Z

Beyond a certain point in the CPU-hotplug offline process, timers get stranded on the outgoing CPU, and won't fire until that CPU comes back online, which might well be never. This commit therefore adds a hook in torture_onoff_init() that is invoked from torture_offline(), which rcutorture uses to occasionally wait for a grace period. This should result in failures for RCU implementations that rely on stranded timers eventually firing in the absence of the CPU coming back online. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney

Merge tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm

2018-08-16T00:39:07Z

Pull drm updates from Dave Airlie: "This is the main drm pull request for 4.19. Rob has some new hardware support for new qualcomm hw that I'll send along separately. This has the display part of it, the remaining pull is for the acceleration engine. This also contains a wound-wait/wait-die mutex rework, Peter has acked it for merging via my tree. Otherwise mostly the usual level of activity. Summary: core: - Wound-wait/wait-die mutex rework - Add writeback connector type - Add "content type" property for HDMI - Move GEM bo to drm_framebuffer - Initial gpu scheduler documentation - GPU scheduler fixes for dying processes - Console deferred fbcon takeover support - Displayport support for CEC tunneling over AUX panel: - otm8009a panel driver fixes - Innolux TV123WAM and G070Y2-L01 panel driver - Ilitek ILI9881c panel driver - Rocktech RK070ER9427 LCD - EDT ETM0700G0EDH6 and EDT ETM0700G0BDH6 - DLC DLC0700YZG-1 - BOE HV070WSA-100 - newhaven, nhd-4.3-480272ef-atxl LCD - DataImage SCF0700C48GGU18 - Sharp LQ035Q7DB03 - p079zca: Refactor to support multiple panels tinydrm: - ILI9341 display panel New driver: - vkms - virtual kms driver to testing. i915: - Icelake: Display enablement DSI support IRQ support Powerwell support - GPU reset fixes and improvements - Full ppgtt support refactoring - PSR fixes and improvements - Execlist improvments - GuC related fixes amdgpu: - Initial amdgpu documentation - JPEG engine support on VCN - CIK uses powerplay by default - Move to using core PCIE functionality for gens/lanes - DC/Powerplay interface rework - Stutter mode support for RV - Vega12 Powerplay updates - GFXOFF fixes - GPUVM fault debugging - Vega12 GFXOFF - DC improvements - DC i2c/aux changes - UVD 7.2 fixes - Powerplay fixes for Polaris12, CZ/ST - command submission bo_list fixes amdkfd: - Raven support - Power management fixes udl: - Cleanups and fixes nouveau: - misc fixes and cleanups. msm: - DPU1 support display controller in sdm845 - GPU coredump support. vmwgfx: - Atomic modesetting validation fixes - Support for multisample surfaces armada: - Atomic modesetting support completed. exynos: - IPPv2 fixes - Move g2d to component framework - Suspend/resume support cleanups - Driver cleanups imx: - CSI configuration improvements - Driver cleanups - Use atomic suspend/resume helpers - ipu-v3 V4L2 XRGB32/XBGR32 support pl111: - Add Nomadik LCDC variant v3d: - GPU scheduler jobs management sun4i: - R40 display engine support - TCON TOP driver mediatek: - MT2712 SoC support rockchip: - vop fixes omapdrm: - Workaround for DRA7 errata i932 - Fix mm_list locking mali-dp: - Writeback implementation PM improvements - Internal error reporting debugfs tilcdc: - Single fix for deferred probing hdlcd: - Teardown fixes tda998x: - Converted to a bridge driver. etnaviv: - Misc fixes" * tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm: (1506 commits) drm/amdgpu/sriov: give 8s for recover vram under RUNTIME drm/scheduler: fix param documentation drm/i2c: tda998x: correct PLL divider calculation drm/i2c: tda998x: get rid of private fill_modes function drm/i2c: tda998x: move mode_valid() to bridge drm/i2c: tda998x: register bridge outside of component helper drm/i2c: tda998x: cleanup from previous changes drm/i2c: tda998x: allocate tda998x_priv inside tda998x_create() drm/i2c: tda998x: convert to bridge driver drm/scheduler: fix timeout worker setup for out of order job completions drm/amd/display: display connected to dp-1 does not light up drm/amd/display: update clk for various HDMI color depths drm/amd/display: program display clock on cache match drm/amd/display: Add NULL check for enabling dp ss drm/amd/display: add vbios table check for enabling dp ss drm/amd/display: Don't share clk source between DP and HDMI drm/amd/display: Fix DP HBR2 Eye Diagram Pattern on Carrizo drm/amd/display: Use calculated disp_clk_khz value for dce110 drm/amd/display: Implement custom degamma lut on dcn drm/amd/display: Destroy aux_engines only once ...

locking: Implement an algorithm choice for Wound-Wait mutexes

2018-07-03T07:44:36Z

The current Wound-Wait mutex algorithm is actually not Wound-Wait but Wait-Die. Implement also Wound-Wait as a per-ww-class choice. Wound-Wait is, contrary to Wait-Die a preemptive algorithm and is known to generate fewer backoffs. Testing reveals that this is true if the number of simultaneous contending transactions is small. As the number of simultaneous contending threads increases, Wait-Wound becomes inferior to Wait-Die in terms of elapsed time. Possibly due to the larger number of held locks of sleeping transactions. Update documentation and callers. Timings using git://people.freedesktop.org/~thomash/ww_mutex_test tag patch-18-06-15 Each thread runs 100000 batches of lock / unlock 800 ww mutexes randomly chosen out of 100000. Four core Intel x86_64: Algorithm #threads Rollbacks time Wound-Wait 4 ~100 ~17s. Wait-Die 4 ~150000 ~19s. Wound-Wait 16 ~360000 ~109s. Wait-Die 16 ~450000 ~82s. Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Gustavo Padovan Cc: Maarten Lankhorst Cc: Sean Paul Cc: David Airlie Cc: Davidlohr Bueso Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Greg Kroah-Hartman Cc: linux-doc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Co-authored-by: Peter Zijlstra Signed-off-by: Thomas Hellstrom Acked-by: Peter Zijlstra (Intel) Acked-by: Ingo Molnar

torture: Keep old-school dmesg format

2018-06-25T18:30:10Z

This commit adds "#define pr_fmt(fmt) fmt" to the torture-test files in order to keep the current dmesg format. Once Joe's commits have hit mainline, these definitions will be changed in order to automatically generate the dmesg line prefix that the scripts expect. This will have the beneficial side-effect of allowing printk() formats to be used more widely and of shortening some pr_*() lines. Signed-off-by: Paul E. McKenney Cc: Joe Perches

torture: Make online/offline messages appear only for verbose=2

2018-06-25T18:30:10Z

Some bugs reproduce quickly only at high CPU-hotplug rates, so the rcutorture TREE03 scenario now has only 200 milliseconds spacing between CPU-hotplug operations. At this rate, the torture-test pair of console messages per operation becomes a bit voluminous. This commit therefore converts the torture-test set of "verbose" kernel-boot arguments from bool to int, and prints the extra console messages only when verbose=2. The default is still verbose=1. Signed-off-by: Paul E. McKenney