From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761344AbdEZA4j (ORCPT ); Thu, 25 May 2017 20:56:39 -0400 Received: from mga14.intel.com ([192.55.52.115]:17794 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757742AbdEZA4h (ORCPT ); Thu, 25 May 2017 20:56:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.38,394,1491289200"; d="scan'208";a="861428621" From: "Huang\, Ying" To: Ming Lei Cc: "Huang\, Ying" , Andrew Morton , , , Johannes Weiner , "Minchan Kim" , Jens Axboe , Ming Lei , Shaohua Li , Subject: Re: [PATCH -mm 06/13] block: Increase BIO_MAX_PAGES to PMD size if THP_SWAP enabled References: <20170525064635.2832-1-ying.huang@intel.com> <20170525064635.2832-7-ying.huang@intel.com> <20170525084238.GA15737@ming.t460p> Date: Fri, 26 May 2017 08:56:23 +0800 In-Reply-To: <20170525084238.GA15737@ming.t460p> (Ming Lei's message of "Thu, 25 May 2017 16:42:44 +0800") Message-ID: <8760goa11k.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ming Lei writes: > On Thu, May 25, 2017 at 02:46:28PM +0800, Huang, Ying wrote: >> From: Huang Ying >> >> In this patch, BIO_MAX_PAGES is changed from 256 to HPAGE_PMD_NR if >> CONFIG_THP_SWAP is enabled and HPAGE_PMD_NR > 256. This is to support >> THP (Transparent Huge Page) swap optimization. Where the THP will be >> write to disk as a whole instead of HPAGE_PMD_NR normal pages to batch >> the various operations during swap. And the page is likely to be >> written to disk to free memory when system memory goes really low, the >> memory pool need to be used to avoid deadlock. >> >> Signed-off-by: "Huang, Ying" >> Cc: Johannes Weiner >> Cc: Minchan Kim >> Cc: Jens Axboe >> Cc: Ming Lei >> Cc: Shaohua Li >> Cc: linux-block@vger.kernel.org >> --- >> include/linux/bio.h | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/include/linux/bio.h b/include/linux/bio.h >> index d1b04b0e99cf..314796486507 100644 >> --- a/include/linux/bio.h >> +++ b/include/linux/bio.h >> @@ -38,7 +38,15 @@ >> #define BIO_BUG_ON >> #endif >> >> +#ifdef CONFIG_THP_SWAP >> +#if HPAGE_PMD_NR > 256 >> +#define BIO_MAX_PAGES HPAGE_PMD_NR >> +#else >> #define BIO_MAX_PAGES 256 >> +#endif >> +#else >> +#define BIO_MAX_PAGES 256 >> +#endif >> >> #define bio_prio(bio) (bio)->bi_ioprio >> #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio) > > Last time we discussed we should use multipage bvec for this usage. > > I will rebase the last post on v4.12-rc and kick if off again since > the raid cleanup is just done on v4.11. > > http://marc.info/?t=148453679000002&r=1&w=2 Thanks for your information! I will rebase my patchset on that after they are merged. From now on, this patch and the next one [07/13] is only a temporary workaround for testing. Best Regards, Huang, Ying > Thanks, > Ming