user/sven/linux.git/kernel/time/clocksource.c, branch v4.18.10

clocksource: Revert "Remove kthread"

2018-09-19T20:41:37Z

commit e2c631ba75a7e727e8db0a9d30a06bfd434adb3a upstream. I turns out that the silly spawn kthread from worker was actually needed. clocksource_watchdog_kthread() cannot be called directly from clocksource_watchdog_work(), because clocksource_select() calls timekeeping_notify() which uses stop_machine(). One cannot use stop_machine() from a workqueue() due lock inversions wrt CPU hotplug. Revert the patch but add a comment that explain why we jump through such apparently silly hoops. Fixes: 7197e77abcb6 ("clocksource: Remove kthread") Reported-by: Siegfried Metz Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Niklas Cassel Tested-by: Kevin Shanahan Tested-by: viktor_jaegerskuepper@freenet.de Tested-by: Siegfried Metz Cc: rafael.j.wysocki@intel.com Cc: len.brown@intel.com Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Cc: bjorn.andersson@linaro.org Link: https://lkml.kernel.org/r/20180905084158.GR24124@hirez.programming.kicks-ass.net Cc: Siegfried Metz Signed-off-by: Greg Kroah-Hartman

clocksource: Move inline keyword to the beginning of function declarations

2018-05-16T20:21:32Z

The inline keyword was not at the beginning of the function declarations. Fix the following warnings triggered when using W=1: kernel/time/clocksource.c:456:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] kernel/time/clocksource.c:457:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] Signed-off-by: Mathieu Malaterre Signed-off-by: Thomas Gleixner Cc: Stephen Boyd Cc: John Stultz Link: https://lkml.kernel.org/r/20180516195943.31924-1-malat@debian.org

clocksource: Remove kthread

2018-05-02T14:11:46Z

The clocksource watchdog uses a work to spawn a kthread to run the watchdog. That is about as silly as it sounds, run the watchdog directly from the work. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Link: https://lkml.kernel.org/r/20180430100344.713862818@infradead.org

clocksource: Rework stale comment

2018-05-02T14:10:41Z

AFAICS the hotplug code no longer uses this function. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Link: https://lkml.kernel.org/r/20180430100344.656525644@infradead.org

clocksource: Consistent de-rate when marking unstable

2018-05-02T14:10:41Z

When a registered clocksource gets marked unstable the watchdog_kthread will de-rate and re-select the clocksource. Ensure it also de-rates when getting called on an unregistered clocksource. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180430100344.594904898@infradead.org

clocksource: Initialize cs->wd_list

2018-05-02T14:10:40Z

A number of places relies on list_empty(&cs->wd_list), however the list_head does not get initialized. Do so upon registration, such that thereafter it is possible to rely on list_empty() correctly reflecting the list membership status. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Diego Viola Reviewed-by: Rafael J. Wysocki Cc: stable@vger.kernel.org Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: rui.zhang@intel.com Link: https://lkml.kernel.org/r/20180430100344.472662715@infradead.org

clocksource: Allow clocksource_mark_unstable() on unregistered clocksources

2018-05-02T14:10:40Z

Because of how the code flips between tsc-early and tsc clocksources it might need to mark one or both unstable. The current code in mark_tsc_unstable() only worked because previously it registered the tsc clocksource once and then never touched it. Since it now unregisters the tsc-early clocksource, it needs to know if a clocksource got unregistered and the current cs->mult test doesn't work for that. Instead use list_empty(&cs->list) to test for registration. Furthermore, since clocksource_mark_unstable() needs to place the cs on the wd_list, it links the cs->list and cs->wd_list serialization. It must not see a clocsource registered (!empty cs->list) but already past dequeue_watchdog(). So place {en,de}queue{,_watchdog}() under the same lock. Provided cs->list is initialized to empty, this then allows us to unconditionally use clocksource_mark_unstable(), regardless of the registration state. Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Rafael J. Wysocki Tested-by: Diego Viola Cc: len.brown@intel.com Cc: rjw@rjwysocki.net Cc: diego.viola@gmail.com Cc: rui.zhang@intel.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180502135312.GS12217@hirez.programming.kicks-ass.net

clocksource: Use ATTRIBUTE_GROUPS

2018-02-28T13:05:07Z

Use ATTRIBUTE_GROUPS instead of manually creating the individual device files. Signed-off-by: Baolin Wang Signed-off-by: Thomas Gleixner Cc: arnd@arndb.de Cc: sboyd@codeaurora.org Cc: broonie@kernel.org Cc: john.stultz@linaro.org Link: https://lkml.kernel.org/r/d80dccb981dc2461781ebb8d71a32ccdc1b0e6f9.1516167691.git.baolin.wang@linaro.org

clocksource: Use DEVICE_ATTR_RW/RO/WO to define device attributes

2018-02-28T13:04:52Z

Convert DEVICE_ATTR to DEVICE_ATTR_RW/RO/WO which is the preferred and simpler way of implementation. Signed-off-by: Baolin Wang Signed-off-by: Thomas Gleixner Cc: arnd@arndb.de Cc: sboyd@codeaurora.org Cc: broonie@kernel.org Cc: john.stultz@linaro.org Link: https://lkml.kernel.org/r/8f35c77e753e957b61187e8e7b2e4a3d61e4a72b.1516167691.git.baolin.wang@linaro.org

clocksource: Don't walk the clocksource list for empty override

2018-02-28T13:04:52Z

If the override clocksource name is empty there is no point in walking the clocksource list for a match. Signed-off-by: Baolin Wang Signed-off-by: Thomas Gleixner Cc: arnd@arndb.de Cc: sboyd@codeaurora.org Cc: broonie@kernel.org Cc: john.stultz@linaro.org Link: https://lkml.kernel.org/r/069ce2a605546bcad6552968cff755f0a03f9f10.1516167691.git.baolin.wang@linaro.org