Hi Greg, On Fri, Mar 8, 2019 at 3:01 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Mar 07, 2019 at 03:59:04PM -0800, Zubin Mithra wrote: > > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > > > commit 38d589f2fd08f1296aea3ce62bebd185125c6d81 upstream > > > > With the ultimate goal of keeping rt_mutex wait_list and futex_q waiters > > consistent it's necessary to split 'rt_mutex_futex_lock()' into finer > > parts, such that only the actual blocking can be done without hb->lock > > held. > > > > Split split_mutex_finish_proxy_lock() into two parts, one that does the > > blocking and one that does remove_waiter() when the lock acquire failed. > > > > When the rtmutex was acquired successfully the waiter can be removed in the > > acquisiton path safely, since there is no concurrency on the lock owner. > > > > This means that, except for futex_lock_pi(), all wait_list modifications > > are done with both hb->lock and wait_lock held. > > > > [bigeasy@xxxxxxxxxxxxx: fix for futex_requeue_pi_signal_restart] > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > > Cc: juri.lelli@xxxxxxx > > Cc: bigeasy@xxxxxxxxxxxxx > > Cc: xlpang@xxxxxxxxxx > > Cc: rostedt@xxxxxxxxxxx > > Cc: mathieu.desnoyers@xxxxxxxxxxxx > > Cc: jdesfossez@xxxxxxxxxxxx > > Cc: dvhart@xxxxxxxxxxxxx > > Cc: bristot@xxxxxxxxxx > > Link: http://lkml.kernel.org/r/20170322104152.001659630@xxxxxxxxxxxxx > > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Signed-off-by: Zubin Mithra <zsm@xxxxxxxxxxxx> > > --- > > kernel/futex.c | 7 +++-- > > kernel/locking/rtmutex.c | 52 ++++++++++++++++++++++++++++----- > > kernel/locking/rtmutex_common.h | 9 ++++-- > > 3 files changed, 56 insertions(+), 12 deletions(-) > > Why is this needed for 4.4.y and not 4.9.y? What bug/issue does it > resolve? > > From the changelog text, all it looks like it is doing here is > reorganizing the code a bit. > > confused, > Was this clarified with v2, or do you still have questions/concerns ? Thanks, Guenter
