From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from LGEAMRELO11.lge.com ([156.147.23.51]:46035 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751046AbeACIXK (ORCPT ); Wed, 3 Jan 2018 03:23:10 -0500 Subject: Re: About the try to remove cross-release feature entirely by Ingo From: Byungchul Park To: Theodore Ts'o , Matthew Wilcox , Byungchul Park , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , david@fromorbit.com, Linus Torvalds , Amir Goldstein , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, oleg@redhat.com, kernel-team@lge.com, daniel@ffwll.ch References: <20171229014736.GA10341@X58A-UD3R> <20171229035146.GA11757@thunk.org> <20171229072851.GA12235@X58A-UD3R> <20171230061624.GA27959@bombadil.infradead.org> <20171230154041.GB3366@thunk.org> <20171230204417.GF27959@bombadil.infradead.org> <20171230224028.GC3366@thunk.org> <20180103070556.GA22583@thunk.org> <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Message-ID: <45973bf8-f20c-ec0c-7e82-71b4d0a64998@lge.com> Date: Wed, 3 Jan 2018 17:23:07 +0900 MIME-Version: 1.0 In-Reply-To: <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On 1/3/2018 5:10 PM, Byungchul Park wrote: > On 1/3/2018 4:05 PM, Theodore Ts'o wrote: >> On Wed, Jan 03, 2018 at 11:10:37AM +0900, Byungchul Park wrote: >>>> The point I was trying to drive home is that "all we have to do is >>>> just classify everything well or just invalidate the right lock >>> >>> Just to be sure, we don't have to invalidate lock objects at all but >>> a problematic waiter only. >> >> So essentially you are proposing that we have to play "whack-a-mole" >> as we find false positives, and where we may have to put in ad-hoc >> plumbing to only invalidate "a problematic waiter" when it's >> problematic --- or to entirely suppress the problematic waiter > > If we have too many problematic completions(waiters) to handle it, > then I agree with you. But so far, only one exits and it seems able > to be handled even in the future on my own. > > Or if you believe that we have a lot of those kind of completions > making trouble so we cannot handle it, the (4) by Amir would work, > no? I'm asking because I'm really curious about your opinion.. > >> altogether.  And in that case, a file system developer might be forced >> to invalidate a lock/"waiter"/"completion" in another subsystem. > > As I said, with regard to the invalidation, we don't have to > consider locks at all. It's enough to invalidate the waiter only. > >> I will also remind you that doing this will trigger a checkpatch.pl >> *error*: > > This is what we decided. And I think the decision is reasonable for > original lockdep. But I wonder if we should apply the same decision > on waiters. I don't insist but just wonder. What if we adopt the (4) in which waiters are validated one by one and no explicit invalidation is involved? >> ERROR("LOCKDEP", "lockdep_no_validate class is reserved for >> device->mutex.\n" . $herecurr); >> >>                                       - Ted >> > -- Thanks, Byungchul From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: About the try to remove cross-release feature entirely by Ingo From: Byungchul Park To: Theodore Ts'o , Matthew Wilcox , Byungchul Park , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , david@fromorbit.com, Linus Torvalds , Amir Goldstein , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, oleg@redhat.com, kernel-team@lge.com, daniel@ffwll.ch References: <20171229014736.GA10341@X58A-UD3R> <20171229035146.GA11757@thunk.org> <20171229072851.GA12235@X58A-UD3R> <20171230061624.GA27959@bombadil.infradead.org> <20171230154041.GB3366@thunk.org> <20171230204417.GF27959@bombadil.infradead.org> <20171230224028.GC3366@thunk.org> <20180103070556.GA22583@thunk.org> <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Message-ID: <45973bf8-f20c-ec0c-7e82-71b4d0a64998@lge.com> Date: Wed, 3 Jan 2018 17:23:07 +0900 MIME-Version: 1.0 In-Reply-To: <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: On 1/3/2018 5:10 PM, Byungchul Park wrote: > On 1/3/2018 4:05 PM, Theodore Ts'o wrote: >> On Wed, Jan 03, 2018 at 11:10:37AM +0900, Byungchul Park wrote: >>>> The point I was trying to drive home is that "all we have to do is >>>> just classify everything well or just invalidate the right lock >>> >>> Just to be sure, we don't have to invalidate lock objects at all but >>> a problematic waiter only. >> >> So essentially you are proposing that we have to play "whack-a-mole" >> as we find false positives, and where we may have to put in ad-hoc >> plumbing to only invalidate "a problematic waiter" when it's >> problematic --- or to entirely suppress the problematic waiter > > If we have too many problematic completions(waiters) to handle it, > then I agree with you. But so far, only one exits and it seems able > to be handled even in the future on my own. > > Or if you believe that we have a lot of those kind of completions > making trouble so we cannot handle it, the (4) by Amir would work, > no? I'm asking because I'm really curious about your opinion.. > >> altogether.  And in that case, a file system developer might be forced >> to invalidate a lock/"waiter"/"completion" in another subsystem. > > As I said, with regard to the invalidation, we don't have to > consider locks at all. It's enough to invalidate the waiter only. > >> I will also remind you that doing this will trigger a checkpatch.pl >> *error*: > > This is what we decided. And I think the decision is reasonable for > original lockdep. But I wonder if we should apply the same decision > on waiters. I don't insist but just wonder. What if we adopt the (4) in which waiters are validated one by one and no explicit invalidation is involved? >> ERROR("LOCKDEP", "lockdep_no_validate class is reserved for >> device->mutex.\n" . $herecurr); >> >>                                       - Ted >> > -- Thanks, Byungchul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 923BA6B02FD for ; Wed, 3 Jan 2018 03:23:10 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id h10so380777pgn.19 for ; Wed, 03 Jan 2018 00:23:10 -0800 (PST) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id l24si348682pgn.528.2018.01.03.00.23.08 for ; Wed, 03 Jan 2018 00:23:09 -0800 (PST) Subject: Re: About the try to remove cross-release feature entirely by Ingo From: Byungchul Park References: <20171229014736.GA10341@X58A-UD3R> <20171229035146.GA11757@thunk.org> <20171229072851.GA12235@X58A-UD3R> <20171230061624.GA27959@bombadil.infradead.org> <20171230154041.GB3366@thunk.org> <20171230204417.GF27959@bombadil.infradead.org> <20171230224028.GC3366@thunk.org> <20180103070556.GA22583@thunk.org> <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Message-ID: <45973bf8-f20c-ec0c-7e82-71b4d0a64998@lge.com> Date: Wed, 3 Jan 2018 17:23:07 +0900 MIME-Version: 1.0 In-Reply-To: <66296fcb-8df0-9697-2825-efa37c234ad9@lge.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Theodore Ts'o , Matthew Wilcox , Byungchul Park , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , david@fromorbit.com, Linus Torvalds , Amir Goldstein , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, oleg@redhat.com, kernel-team@lge.com, daniel@ffwll.ch On 1/3/2018 5:10 PM, Byungchul Park wrote: > On 1/3/2018 4:05 PM, Theodore Ts'o wrote: >> On Wed, Jan 03, 2018 at 11:10:37AM +0900, Byungchul Park wrote: >>>> The point I was trying to drive home is that "all we have to do is >>>> just classify everything well or just invalidate the right lock >>> >>> Just to be sure, we don't have to invalidate lock objects at all but >>> a problematic waiter only. >> >> So essentially you are proposing that we have to play "whack-a-mole" >> as we find false positives, and where we may have to put in ad-hoc >> plumbing to only invalidate "a problematic waiter" when it's >> problematic --- or to entirely suppress the problematic waiter > > If we have too many problematic completions(waiters) to handle it, > then I agree with you. But so far, only one exits and it seems able > to be handled even in the future on my own. > > Or if you believe that we have a lot of those kind of completions > making trouble so we cannot handle it, the (4) by Amir would work, > no? I'm asking because I'm really curious about your opinion.. > >> altogether.A And in that case, a file system developer might be forced >> to invalidate a lock/"waiter"/"completion" in another subsystem. > > As I said, with regard to the invalidation, we don't have to > consider locks at all. It's enough to invalidate the waiter only. > >> I will also remind you that doing this will trigger a checkpatch.pl >> *error*: > > This is what we decided. And I think the decision is reasonable for > original lockdep. But I wonder if we should apply the same decision > on waiters. I don't insist but just wonder. What if we adopt the (4) in which waiters are validated one by one and no explicit invalidation is involved? >> ERROR("LOCKDEP", "lockdep_no_validate class is reserved for >> device->mutex.\n" . $herecurr); >> >> A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A - Ted >> > -- Thanks, Byungchul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org