similar to: [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock

change from v2: __spin_yeild_cpu() will yield slices to lpar if target cpu is running. remove unnecessary rmb() in __spin_yield/wake_cpu. __pv_wait() will check the *ptr == val. some commit message change change fome v1: separate into 6 pathes from one patch some minor code changes. I do several tests on pseries IBM,8408-E8E with 32cpus, 64GB memory. benchmark test results are below. 2

change from v2: __spin_yeild_cpu() will yield slices to lpar if target cpu is running. remove unnecessary rmb() in __spin_yield/wake_cpu. __pv_wait() will check the *ptr == val. some commit message change change fome v1: separate into 6 pathes from one patch some minor code changes. I do several tests on pseries IBM,8408-E8E with 32cpus, 64GB memory. benchmark test results are below. 2

From: root <root at ltcalpine2-lp13.aus.stglabs.ibm.com> change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

From: root <root at ltcalpine2-lp13.aus.stglabs.ibm.com> change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. sorry for not even doing a test on bigendian machine before!!! change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

change from v4: BUG FIX. thanks boqun reporting this issue. struct __qspinlock has different layout in bigendian mahcine. native_queued_spin_unlock() may write value to a wrong address. now fix it. sorry for not even doing a test on bigendian machine before!!! change from v3: a big change in [PATCH v4 4/6] pv-qspinlock: powerpc support pv-qspinlock no other patch changed. and the patch

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v7 -> v8: add one patch to drop a function call

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

Hi All, this is the fairlock patchset. You can apply them and build successfully. patches are based on linux-next qspinlock can avoid waiter starved issue. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. v8 -> v9: mv qspinlocm config entry to

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/powerpc/include/asm/qspinlock_paravirt.h | 36 +++++++++++++++

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/powerpc/include/asm/qspinlock_paravirt.h | 36 +++++++++++++++

On Thu, 2016-06-02 at 17:22 +0800, Pan Xinhui wrote: > Base code to enable qspinlock on powerpc. this patch add some #ifdef > here and there. Although there is no paravirt related code, we can > successfully build a qspinlock kernel after apply this patch. This is missing the IO_SYNC stuff ... It means we'll fail to do a full sync to order vs MMIOs. You need to add that back in the

On Thu, 2016-06-02 at 17:22 +0800, Pan Xinhui wrote: > Base code to enable qspinlock on powerpc. this patch add some #ifdef > here and there. Although there is no paravirt related code, we can > successfully build a qspinlock kernel after apply this patch. This is missing the IO_SYNC stuff ... It means we'll fail to do a full sync to order vs MMIOs. You need to add that back in the

v2 is updated to account for feedback from Will, Peter, and Waiman (thank you), and trims off a couple of RFC and unrelated patches. Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued

On Mon, Dec 05, 2016 at 10:19:21AM -0500, Pan Xinhui wrote: > This patch add basic code to enable qspinlock on powerpc. qspinlock is > one kind of fairlock implementation. And seen some performance improvement > under some scenarios. > > queued_spin_unlock() release the lock by just one write of NULL to the > ::locked field which sits at different places in the two endianness

On Mon, Dec 05, 2016 at 10:19:21AM -0500, Pan Xinhui wrote: > This patch add basic code to enable qspinlock on powerpc. qspinlock is > one kind of fairlock implementation. And seen some performance improvement > under some scenarios. > > queued_spin_unlock() release the lock by just one write of NULL to the > ::locked field which sits at different places in the two endianness

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt

v3 is updated to use __pv_queued_spin_unlock, noticed by Waiman (thank you). Thanks, Nick Nicholas Piggin (6): powerpc/powernv: must include hvcall.h to get PAPR defines powerpc/pseries: move some PAPR paravirt functions to their own file powerpc: move spinlock implementation to simple_spinlock powerpc/64s: implement queued spinlocks and rwlocks powerpc/pseries: implement paravirt

Updated with everybody's feedback (thanks all), and more performance results. What I've found is I might have been measuring the worst load point for the paravirt case, and by looking at a range of loads it's clear that queued spinlocks are overall better even on PV, doubly so when you look at the generally much improved worst case latencies. I have defaulted it to N even though