From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nagarathnam Muthusamy Subject: Re: [RESEND PATCH V4] pidns: introduce syscall translate_pid Date: Tue, 3 Apr 2018 14:51:04 -0700 Message-ID: <6a117d9a-f005-e1ae-5632-25e5c61dcb8f@oracle.com> References: <1522706249-11578-1-git-send-email-nagarathnam.muthusamy@oracle.com> <20180403143838.614ecc083835d07d409a699c@linux-foundation.org> <678f275b-8d78-9b0f-177f-5ff5c9c55657@oracle.com> <20180403145248.fb4cd8c5ccd270ca77fd18f3@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180403145248.fb4cd8c5ccd270ca77fd18f3@linux-foundation.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton Cc: linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com, khlebnikov@yandex-team.ru, serge.hallyn@ubuntu.com, oleg@redhat.com, luto@amacapital.net, jannh@google.com, prakash.sangappa@oracle.com List-Id: linux-api@vger.kernel.org On 04/03/2018 02:52 PM, Andrew Morton wrote: > On Tue, 3 Apr 2018 14:45:28 -0700 Nagarathnam Muthusamy wrote: > >>> This changelog doesn't explain what the value is to our users. I >>> assume it is a performance optimization because "backward translation >>> requires scanning all tasks"? If so, please show us real-world >>> examples of the performance benefit from this patch, and please go to >>> great lengths to explain to us why this optimisation is needed by our >>> users. >> One of the usecase by Oracle database involves multiple levels of >> nested pid namespaces and we require pid translation between the >> levels. Discussions on the particular usecase, why any of the existing >> methods was not usable happened in the following thread. >> >> https://patchwork.kernel.org/patch/10276785/ >> >> At the end, it was agreed that this patch along with flocks will solve the >> issue. > Nobody who reads this patch's changelog will know any of this. Please > let's get all this information into the proper place. Sure! Will resend the patch with updated change log. Thanks, Nagarathnam. >