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=-15.8 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, URIBL_BLOCKED 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 63323C433B4 for ; Wed, 21 Apr 2021 17:39:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 201B361430 for ; Wed, 21 Apr 2021 17:39:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242908AbhDURkU (ORCPT ); Wed, 21 Apr 2021 13:40:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27431 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235434AbhDURkT (ORCPT ); Wed, 21 Apr 2021 13:40:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619026785; 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=NozKqtAQsLfIuTJYfL4jEF5T8uHtk7yVgiyg7jRNbZo=; b=g6BfZ85MukkGC9o21UNmIT0BsnXigHt97H+bJm4FiyBhq5fIZaKUIGRwq9zEL7V3jR2+s+ PPVRJmWhCy79qXIHtlXcGbPu1BJygxcfrU4gsu1HNXRYNZXO6+/dSItqoeda7cm7X+yQ7H 72l/ZFyD9xX6NrL0jx3zcOpN5ul+hsM= 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-438-R1oJopAjPNS_ZDvua3z3Zg-1; Wed, 21 Apr 2021 13:39:36 -0400 X-MC-Unique: R1oJopAjPNS_ZDvua3z3Zg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8EAE28030C9; Wed, 21 Apr 2021 17:39:35 +0000 (UTC) Received: from horse.redhat.com (ovpn-114-206.rdu2.redhat.com [10.10.114.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id 26E885D769; Wed, 21 Apr 2021 17:39:32 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id B4E70220BCF; Wed, 21 Apr 2021 13:39:31 -0400 (EDT) Date: Wed, 21 Apr 2021 13:39:31 -0400 From: Vivek Goyal To: Greg Kurz Cc: linux-fsdevel@vger.kernel.org, dan.j.williams@intel.com, jack@suse.cz, willy@infradead.org, linux-nvdimm@lists.01.org, miklos@szeredi.hu, linux-kernel@vger.kernel.org, virtio-fs@redhat.com Subject: Re: [Virtio-fs] [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry() Message-ID: <20210421173931.GF1579961@redhat.com> References: <20210419213636.1514816-1-vgoyal@redhat.com> <20210419213636.1514816-3-vgoyal@redhat.com> <20210420093420.2eed3939@bahia.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210420093420.2eed3939@bahia.lan> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Apr 20, 2021 at 09:34:20AM +0200, Greg Kurz wrote: > On Mon, 19 Apr 2021 17:36:35 -0400 > Vivek Goyal wrote: > > > As of now put_unlocked_entry() always wakes up next waiter. In next > > patches we want to wake up all waiters at one callsite. Hence, add a > > parameter to the function. > > > > This patch does not introduce any change of behavior. > > > > Suggested-by: Dan Williams > > Signed-off-by: Vivek Goyal > > --- > > fs/dax.c | 13 +++++++------ > > 1 file changed, 7 insertions(+), 6 deletions(-) > > > > diff --git a/fs/dax.c b/fs/dax.c > > index 00978d0838b1..f19d76a6a493 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state *xas, void *entry) > > finish_wait(wq, &ewait.wait); > > } > > > > -static void put_unlocked_entry(struct xa_state *xas, void *entry) > > +static void put_unlocked_entry(struct xa_state *xas, void *entry, > > + enum dax_entry_wake_mode mode) > > { > > /* If we were the only waiter woken, wake the next one */ > > With this change, the comment is no longer accurate since the > function can now wake all waiters if passed mode == WAKE_ALL. > Also, it paraphrases the code which is simple enough, so I'd > simply drop it. Ok, I will get rid of this comment. Agreed that code is simple enough. And frankly speaking I don't even understand "If we were the only waiter woken" part. How do we know that only this caller was woken. Vivek > > This is minor though and it shouldn't prevent this fix to go > forward. > > Reviewed-by: Greg Kurz > > > if (entry && !dax_is_conflict(entry)) > > - dax_wake_entry(xas, entry, WAKE_NEXT); > > + dax_wake_entry(xas, entry, mode); > > } > > > > /* > > @@ -633,7 +634,7 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping, > > entry = get_unlocked_entry(&xas, 0); > > if (entry) > > page = dax_busy_page(entry); > > - put_unlocked_entry(&xas, entry); > > + put_unlocked_entry(&xas, entry, WAKE_NEXT); > > if (page) > > break; > > if (++scanned % XA_CHECK_SCHED) > > @@ -675,7 +676,7 @@ static int __dax_invalidate_entry(struct address_space *mapping, > > mapping->nrexceptional--; > > ret = 1; > > out: > > - put_unlocked_entry(&xas, entry); > > + put_unlocked_entry(&xas, entry, WAKE_NEXT); > > xas_unlock_irq(&xas); > > return ret; > > } > > @@ -954,7 +955,7 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev, > > return ret; > > > > put_unlocked: > > - put_unlocked_entry(xas, entry); > > + put_unlocked_entry(xas, entry, WAKE_NEXT); > > return ret; > > } > > > > @@ -1695,7 +1696,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order) > > /* Did we race with someone splitting entry or so? */ > > if (!entry || dax_is_conflict(entry) || > > (order == 0 && !dax_is_pte_entry(entry))) { > > - put_unlocked_entry(&xas, entry); > > + put_unlocked_entry(&xas, entry, WAKE_NEXT); > > xas_unlock_irq(&xas); > > trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf, > > VM_FAULT_NOPAGE); >