From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E3E2C433B4 for ; Tue, 20 Apr 2021 08:35:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0FF3611F2 for ; Tue, 20 Apr 2021 08:35:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231131AbhDTIgA (ORCPT ); Tue, 20 Apr 2021 04:36:00 -0400 Received: from 2.mo51.mail-out.ovh.net ([178.33.255.19]:40756 "EHLO 2.mo51.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229874AbhDTIf6 (ORCPT ); Tue, 20 Apr 2021 04:35:58 -0400 X-Greylist: delayed 3603 seconds by postgrey-1.27 at vger.kernel.org; Tue, 20 Apr 2021 04:35:58 EDT Received: from mxplan5.mail.ovh.net (unknown [10.108.1.72]) by mo51.mail-out.ovh.net (Postfix) with ESMTPS id DD7D0282FA1; Tue, 20 Apr 2021 09:19:26 +0200 (CEST) Received: from kaod.org (37.59.142.106) by DAG8EX1.mxp5.local (172.16.2.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Tue, 20 Apr 2021 09:19:26 +0200 Authentication-Results: garm.ovh; auth=pass (GARM-106R006e0384a78-5e6d-4b83-a0a2-258cc1ae5f18, F8484F3EE3345E552A9359E6756AA457A7210C68) smtp.auth=groug@kaod.org X-OVh-ClientIp: 78.197.208.248 Date: Tue, 20 Apr 2021 09:19:25 +0200 From: Greg Kurz To: Vivek Goyal CC: , , , , , , , Subject: Re: [Virtio-fs] [PATCH v3 1/3] dax: Add an enum for specifying dax wakup mode Message-ID: <20210420091925.08054e8b@bahia.lan> In-Reply-To: <20210419213636.1514816-2-vgoyal@redhat.com> References: <20210419213636.1514816-1-vgoyal@redhat.com> <20210419213636.1514816-2-vgoyal@redhat.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [37.59.142.106] X-ClientProxiedBy: DAG9EX2.mxp5.local (172.16.2.82) To DAG8EX1.mxp5.local (172.16.2.71) X-Ovh-Tracer-GUID: 4fd4651b-4865-4921-847a-6cdede9f3c7e X-Ovh-Tracer-Id: 9258837884391430447 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrvddthedguddvtdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvuffkjghfofggtgfgihesthejredtredtvdenucfhrhhomhepifhrvghgucfmuhhriicuoehgrhhouhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepfedutdeijeejveehkeeileetgfelteekteehtedtieefffevhffflefftdefleejnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrddutdeinecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopehvihhrthhiohdqfhhssehrvgguhhgrthdrtghomh Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 19 Apr 2021 17:36:34 -0400 Vivek Goyal wrote: > Dan mentioned that he is not very fond of passing around a boolean true/false > to specify if only next waiter should be woken up or all waiters should be > woken up. He instead prefers that we introduce an enum and make it very > explicity at the callsite itself. Easier to read code. > > This patch should not introduce any change of behavior. > > Suggested-by: Dan Williams > Signed-off-by: Vivek Goyal > --- Reviewed-by: Greg Kurz > fs/dax.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index b3d27fdc6775..00978d0838b1 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -144,6 +144,16 @@ struct wait_exceptional_entry_queue { > struct exceptional_entry_key key; > }; > > +/** > + * enum dax_entry_wake_mode: waitqueue wakeup toggle > + * @WAKE_NEXT: entry was not mutated > + * @WAKE_ALL: entry was invalidated, or resized > + */ > +enum dax_entry_wake_mode { > + WAKE_NEXT, > + WAKE_ALL, > +}; > + > static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas, > void *entry, struct exceptional_entry_key *key) > { > @@ -182,7 +192,8 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, > * The important information it's conveying is whether the entry at > * this index used to be a PMD entry. > */ > -static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all) > +static void dax_wake_entry(struct xa_state *xas, void *entry, > + enum dax_entry_wake_mode mode) > { > struct exceptional_entry_key key; > wait_queue_head_t *wq; > @@ -196,7 +207,7 @@ static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all) > * must be in the waitqueue and the following check will see them. > */ > if (waitqueue_active(wq)) > - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); > + __wake_up(wq, TASK_NORMAL, mode == WAKE_ALL ? 0 : 1, &key); > } > > /* > @@ -268,7 +279,7 @@ static void put_unlocked_entry(struct xa_state *xas, void *entry) > { > /* If we were the only waiter woken, wake the next one */ > if (entry && !dax_is_conflict(entry)) > - dax_wake_entry(xas, entry, false); > + dax_wake_entry(xas, entry, WAKE_NEXT); > } > > /* > @@ -286,7 +297,7 @@ static void dax_unlock_entry(struct xa_state *xas, void *entry) > old = xas_store(xas, entry); > xas_unlock_irq(xas); > BUG_ON(!dax_is_locked(old)); > - dax_wake_entry(xas, entry, false); > + dax_wake_entry(xas, entry, WAKE_NEXT); > } > > /* > @@ -524,7 +535,7 @@ static void *grab_mapping_entry(struct xa_state *xas, > > dax_disassociate_entry(entry, mapping, false); > xas_store(xas, NULL); /* undo the PMD join */ > - dax_wake_entry(xas, entry, true); > + dax_wake_entry(xas, entry, WAKE_ALL); > mapping->nrexceptional--; > entry = NULL; > xas_set(xas, index); > @@ -937,7 +948,7 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev, > xas_lock_irq(xas); > xas_store(xas, entry); > xas_clear_mark(xas, PAGECACHE_TAG_DIRTY); > - dax_wake_entry(xas, entry, false); > + dax_wake_entry(xas, entry, WAKE_NEXT); > > trace_dax_writeback_one(mapping->host, index, count); > return ret;