Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752546AbbHURo5 (ORCPT ); Fri, 21 Aug 2015 13:44:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55586 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751576AbbHURoz (ORCPT ); Fri, 21 Aug 2015 13:44:55 -0400 Date: Fri, 21 Aug 2015 19:42:30 +0200 From: Oleg Nesterov To: Paul McKenney Cc: Ingo Molnar , Linus Torvalds , Peter Zijlstra , Tejun Heo , linux-kernel@vger.kernel.org Subject: [PATCH v2 0/8] Add rcu_sync infrastructure to avoid _expedited() in percpu-rwsem Message-ID: <20150821174230.GA17867@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1521 Lines: 40 Hello, Now that sb->s_writers was changed to use percpu_rw_semaphore let me send v2. Changes: - whitespace fix in 1/8. - remove EXPORT_SYMBOL() in 3/8, currently rcu_sync has no modular users. - 5/8 is new. This ugly hack pairs with another one: "shift percpu_counter_destroy() into destroy_super_work()" https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git/commit/?h=for-next&id=853b39a7c82826b8413048feec7bf08e98ce7a84 They both will be reverted later. The problem is that we have 2 series routed via different trees, RCU and VFS. We need this hack to ensure that this series won't break alloc_super() which currently assumes that destroy_super()->percpu_free_rwsem() is safe after kzalloc(). This way these 2 series do not depend on each other, we can test/change/revert/etc them independently. We will add rcu_sync_dtor() into deactivate_locked_super() later and revert both hacks. Oleg. include/linux/percpu-rwsem.h | 3 +- include/linux/rcusync.h | 56 +++++++++++++++ kernel/locking/percpu-rwsem.c | 85 ++++++++--------------- kernel/rcu/Makefile | 2 +- kernel/rcu/sync.c | 151 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 240 insertions(+), 57 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/