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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 2807BC433B4 for ; Wed, 28 Apr 2021 17:03:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D42816143A for ; Wed, 28 Apr 2021 17:03:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241235AbhD1RE0 (ORCPT ); Wed, 28 Apr 2021 13:04:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53007 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229993AbhD1RE0 (ORCPT ); Wed, 28 Apr 2021 13:04:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619629421; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CjDGbDf+FlwoYQPnj5RXe7XBw9FtNTs+krtCG4E8T5c=; b=XZSr3HA3tJzfeT/UMwrgaw8cl+I0JPs3rHytS3I//Bqbmi8nT9SeiMrTvNMLzYMvQSKH2g b/H0U3XfxeRCM6yxsknnaVihr0iw11my2bqDA3TEh2WQny3HD+mFs0Fa9prKwnHOvCG8ZV 7qNlf0JvgnR0QSbci8sC/Dg9DQhZqkg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-379-seSeOOSvMY6ySr8ScifKYA-1; Wed, 28 Apr 2021 13:03:39 -0400 X-MC-Unique: seSeOOSvMY6ySr8ScifKYA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 796B2804030; Wed, 28 Apr 2021 17:03:37 +0000 (UTC) Received: from horse.redhat.com (ovpn-116-128.rdu2.redhat.com [10.10.116.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id A633510190A7; Wed, 28 Apr 2021 17:03:30 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id CB27B220BCF; Wed, 28 Apr 2021 13:03:29 -0400 (EDT) Date: Wed, 28 Apr 2021 13:03:29 -0400 From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, virtio-fs@redhat.com, dan.j.williams@intel.com Cc: miklos@szeredi.hu, jack@suse.cz, willy@infradead.org, slp@redhat.com, Greg Kurz Subject: Re: [PATCH v5 1/3] dax: Add an enum for specifying dax wakup mode Message-ID: <20210428170329.GB1840673@redhat.com> References: <20210428165040.1856202-1-vgoyal@redhat.com> <20210428165040.1856202-2-vgoyal@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210428165040.1856202-2-vgoyal@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Apr 28, 2021 at 12:50:38PM -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. > > Reviewed-by: Greg Kurz > Reviewed-by: Jan Kara > Suggested-by: Dan Williams > Signed-off-by: Vivek Goyal > --- > fs/dax.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index b3d27fdc6775..c8cd2ae4440b 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_wake_mode: waitqueue wakeup behaviour > + * @WAKE_NEXT: wake only the first waiter in the waitqueue > + * @WAKE_ALL: wake all waiters in the waitqueue > + */ I just noticed that I did not change order in comments. Will post another version. Sorry about the noise. Vivek > +enum dax_wake_mode { > + WAKE_ALL, > + WAKE_NEXT, > +}; > + > 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_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; > -- > 2.25.4 >