From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 14/17] bcache: back to cache all readahead I/Os Date: Thu, 23 Jan 2020 18:14:22 -0700 Message-ID: <6d72473b-db79-d32a-055c-05a34f2d2b12@kernel.dk> References: <20200123170142.98974-1-colyli@suse.de> <20200123170142.98974-15-colyli@suse.de> <31f7f6b4-98ea-3cf6-44cc-a9ba67484eb0@kernel.dk> <6373da22-9dc1-9525-4048-2c533407c917@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-pf1-f195.google.com ([209.85.210.195]:33652 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729151AbgAXBOY (ORCPT ); Thu, 23 Jan 2020 20:14:24 -0500 Received: by mail-pf1-f195.google.com with SMTP id n7so255999pfn.0 for ; Thu, 23 Jan 2020 17:14:24 -0800 (PST) In-Reply-To: <6373da22-9dc1-9525-4048-2c533407c917@suse.de> Content-Language: en-US Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Coly Li Cc: Michael Lyle , linux-bcache , linux-block@vger.kernel.org, stable On 1/23/20 5:49 PM, Coly Li wrote: > On 2020/1/24 2:31 上午, Jens Axboe wrote: >> On 1/23/20 10:27 AM, Coly Li wrote: >>> On 2020/1/24 1:19 上午, Michael Lyle wrote: >>>> Hi Coly and Jens-- >>>> >>>> One concern I have with this is that it's going to wear out >>>> limited-lifetime SSDs a -lot- faster. Was any thought given to making >>>> this a tunable instead of just changing the behavior? Even if we have >>>> an anecdote or two that it seems to have increased performance for >>>> some workloads, I don't expect it will have increased performance in >>>> general and it may even be costly for some workloads (it all comes >>>> down to what is more useful in the cache-- somewhat-recently readahead >>>> data, or the data that it is displacing). >>> >>> Hi Mike, >>> >>> Copied. This is good suggestion, I will do it after I back from Lunar >>> New Year vacation, and submit it with other tested patches in following >>> v5.6-rc versions. >> >> Do you want me to just drop this patch for now from the series? >> > Hi Jens, > > OK, please drop this patch from this series. I will re-submit the patch > with sysfs interface later with other patches. Sounds good, I queued up the rest for 5.6. -- Jens Axboe