From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 2D67B875 for ; Tue, 6 May 2014 17:01:03 +0000 (UTC) Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 0535520245 for ; Tue, 6 May 2014 17:01:01 +0000 (UTC) Message-ID: <536915C1.7020902@fb.com> Date: Tue, 6 May 2014 13:02:57 -0400 From: Chris Mason MIME-Version: 1.0 To: Pavel Emelyanov References: <53679974.60206@fb.com> <5368ECB7.50205@fb.com> <53690340.4020007@parallels.com> In-Reply-To: <53690340.4020007@parallels.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: "ksummit-discuss@lists.linuxfoundation.org" Subject: Re: [Ksummit-discuss] [CORE TOPIC] [TECH TOPIC] live kernel patching List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 05/06/2014 11:44 AM, Pavel Emelyanov wrote: > On 05/06/2014 06:07 PM, Chris Mason wrote: > >>>> Tons of interest in this topic here, mostly for the in-memory database >>>> workloads. >>> >>> Would in-memory databases be happier if there were a way to kexec >>> without losing your data? >> >> Yes, for these apps we could just define a chunk of ram that was >> supposed to stay the same after kexec and they would be happy. > > +1, I'd be happy to have this as well. > > One question about the chunk of memory you want to preserve -- is it anonymous > memory or part of a page cache? We have plain old memcached, and other fancier stuff is that is page cache based. I think for memcached they've set it up to use shm so app restarts don't toss the ram. -chris