From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 64B796B0279 for ; Thu, 25 May 2017 04:43:02 -0400 (EDT) Received: by mail-qk0-f197.google.com with SMTP id v195so80188089qka.1 for ; Thu, 25 May 2017 01:43:02 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id s129si2444254qkc.31.2017.05.25.01.43.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 May 2017 01:43:01 -0700 (PDT) Date: Thu, 25 May 2017 16:42:44 +0800 From: Ming Lei Subject: Re: [PATCH -mm 06/13] block: Increase BIO_MAX_PAGES to PMD size if THP_SWAP enabled Message-ID: <20170525084238.GA15737@ming.t460p> References: <20170525064635.2832-1-ying.huang@intel.com> <20170525064635.2832-7-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170525064635.2832-7-ying.huang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Huang, Ying" Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , Minchan Kim , Jens Axboe , Ming Lei , Shaohua Li , linux-block@vger.kernel.org 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, Ming -- 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