From patchwork Thu May 31 03:39:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Snitzer X-Patchwork-Id: 10440217 X-Patchwork-Delegate: snitzer@redhat.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BF8EF602BF for ; Thu, 31 May 2018 03:39:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE297292D9 for ; Thu, 31 May 2018 03:39:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2768293C3; Thu, 31 May 2018 03:39:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 53DE3292D9 for ; Thu, 31 May 2018 03:39:33 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.25]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 21209ED185; Thu, 31 May 2018 03:39:31 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 493182010CA1; Thu, 31 May 2018 03:39:29 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 7A8EB1800C9B; Thu, 31 May 2018 03:39:25 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id w4V3dMs3002243 for ; Wed, 30 May 2018 23:39:23 -0400 Received: by smtp.corp.redhat.com (Postfix) id D85AF83B8F; Thu, 31 May 2018 03:39:22 +0000 (UTC) Delivered-To: dm-devel@redhat.com Received: from localhost (ovpn-112-61.rdu2.redhat.com [10.10.112.61]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8D65483B8D; Thu, 31 May 2018 03:39:20 +0000 (UTC) Date: Wed, 30 May 2018 23:39:19 -0400 From: Mike Snitzer To: Mikulas Patocka Message-ID: <20180531033919.GA88973@redhat.com> References: <20180530131623.GB2106@redhat.com> <20180530132647.GB5157@redhat.com> <20180530135421.GA81788@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: dm-devel@redhat.com Cc: Dan Williams , device-mapper development , linux-nvdimm Subject: Re: [dm-devel] [patch 4/4] dm-writecache: use new API for flushing X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.25 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 31 May 2018 03:39:32 +0000 (UTC) X-Virus-Scanned: ClamAV using ClamSMTP On Wed, May 30 2018 at 10:09P -0400, Mikulas Patocka wrote: > And what about this? > #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) > > The code that I had just allowed the compiler to optimize out > persistent-memory code if we have DM_WRITECACHE_ONLY_SSD defined - and you > deleted it. > > Most architectures don't have persistent memory and the dm-writecache > driver could work in ssd-only mode on them. On these architectures, I > define > #define WC_MODE_PMEM(wc) false > - and the compiler will just automatically remove the tests for that > condition and the unused branch. It does also eliminate unused static > functions. Here is the patch that I just folded into the rebased version of dm-writecache now in the dm-4.18 branch. (I rebased ontop of Jens' latest block tree for 4.18 that now includes the mempool_init changes, etc.) --- drivers/md/dm-writecache.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index fcbfaf7c27ec..691b5ffb799f 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -34,13 +34,21 @@ #define BITMAP_GRANULARITY PAGE_SIZE #endif +#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) +#define DM_WRITECACHE_HAS_PMEM +#endif + +#ifdef DM_WRITECACHE_HAS_PMEM #define pmem_assign(dest, src) \ do { \ typeof(dest) uniq = (src); \ memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ } while (0) +#else +#define pmem_assign(dest, src) ((dest)) = (src)) +#endif -#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(CONFIG_ARCH_HAS_PMEM_API) +#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM) #define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS #endif @@ -87,8 +95,13 @@ struct wc_entry { #endif }; +#ifdef DM_WRITECACHE_HAS_PMEM #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) #define WC_MODE_FUA(wc) ((wc)->writeback_fua) +#else +#define WC_MODE_PMEM(wc) false +#define WC_MODE_FUA(wc) false +#endif #define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) struct dm_writecache { @@ -1857,7 +1870,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) if (!strcasecmp(string, "s")) { wc->pmem_mode = false; } else if (!strcasecmp(string, "p")) { -#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) +#ifdef DM_WRITECACHE_HAS_PMEM wc->pmem_mode = true; wc->writeback_fua = true; #else