From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4272EC43381 for ; Mon, 11 Mar 2019 21:54:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 043E3214AE for ; Mon, 11 Mar 2019 21:54:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552341291; bh=Rf7Qx4OjJud1ntNvIaD7uYkdwZymlfGW977GsbO2PCw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZyXFU/BRNeh6cNayYYFGtNFXW3jbGxtCPGx/k6YT7ihm4vD6mPlT721qOIjUfcej0 am2DJWe5zrAXjl0nRB6lHt5Tnaioe0XjLrIW4cj1xOihq0gpPl7dNqYyDLCk4Rf54S qMY30RXrdUbRJgETTy0i0UEq99IvtUlZ0FMujEEs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727008AbfCKVyu (ORCPT ); Mon, 11 Mar 2019 17:54:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:35310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727459AbfCKVyu (ORCPT ); Mon, 11 Mar 2019 17:54:50 -0400 Received: from localhost (unknown [104.133.8.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 955632147C; Mon, 11 Mar 2019 21:54:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552341289; bh=Rf7Qx4OjJud1ntNvIaD7uYkdwZymlfGW977GsbO2PCw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DJk05gqstV5UM3XKDN7zXeXmVbIYPOfv874XfCYILCbXKy6rXTG+VPVup7JoRheOq MyanQhN8e7WzWvOs/ncGt5F6PWT6iC6NgM/rJjMI6Jlpg0G44xaw32P6XD8Y0rt5t9 Dyj2y5vByfD4vn89B6jfoMxhs/jTNp3RjZMsL92s= Date: Mon, 11 Mar 2019 14:54:48 -0700 From: Greg KH To: Guenter Roeck Cc: Zubin Mithra , "# v4 . 10+" , Guenter Roeck , Thomas Gleixner , Ingo Molnar , peterz@infradead.org, dvhart@infradead.org Subject: Re: [PATCH v4.4.y] futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock() Message-ID: <20190311215448.GC32415@kroah.com> References: <20190307235904.18631-1-zsm@chromium.org> <20190308110125.GA5014@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Mar 11, 2019 at 01:54:09PM -0700, Guenter Roeck wrote: > Hi Greg, > > On Fri, Mar 8, 2019 at 3:01 AM Greg KH wrote: > > > > On Thu, Mar 07, 2019 at 03:59:04PM -0800, Zubin Mithra wrote: > > > From: Peter Zijlstra > > > > > > 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@linutronix.de: fix for futex_requeue_pi_signal_restart] > > > > > > Signed-off-by: Peter Zijlstra (Intel) > > > Cc: juri.lelli@arm.com > > > Cc: bigeasy@linutronix.de > > > Cc: xlpang@redhat.com > > > Cc: rostedt@goodmis.org > > > Cc: mathieu.desnoyers@efficios.com > > > Cc: jdesfossez@efficios.com > > > Cc: dvhart@infradead.org > > > Cc: bristot@redhat.com > > > Link: http://lkml.kernel.org/r/20170322104152.001659630@infradead.org > > > Signed-off-by: Thomas Gleixner > > > Signed-off-by: Zubin Mithra > > > --- > > > 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 ? It's all good, sorry, on the road this week, so catching up on stable patches is going to take a while... greg k-h