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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 53331C433B4 for ; Wed, 5 May 2021 12:39:18 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C9DB561132 for ; Wed, 5 May 2021 12:39:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9DB561132 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43166 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1leGo8-0003bL-Sc for qemu-devel@archiver.kernel.org; Wed, 05 May 2021 08:39:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41930) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1leGmx-0002Oe-S7 for qemu-devel@nongnu.org; Wed, 05 May 2021 08:38:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:45451) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1leGmt-0000gS-OG for qemu-devel@nongnu.org; Wed, 05 May 2021 08:38:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620218278; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uEfQroOalMcn+8rvSJLZzx1v7ZCUfwwTwTJytEDOzvc=; b=XbfzUN5K34oyoStFOh6y8L+LpeCydrqk090aC3jlWkVB4nq0RnxfJFKGXWCBUCR0K2joW6 BhQHp8wt0gI4HBkCdPGByAcUs7oIbGaEFu/Kihbe31ix6OiaKNBlMgRBZCSl+VJei+PTJr p62Rg9fY1pmoYypE8cFjgTjzjR7e3Wk= 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-263-xD8T4rEcOySck1JJ_OPW7A-1; Wed, 05 May 2021 08:37:56 -0400 X-MC-Unique: xD8T4rEcOySck1JJ_OPW7A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8D2BC8049EF; Wed, 5 May 2021 12:37:55 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-115-153.ams2.redhat.com [10.36.115.153]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CBB2C5D9C0; Wed, 5 May 2021 12:37:53 +0000 (UTC) Subject: Re: [PATCH v2 1/9] block/write-threshold: don't use write notifiers To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20210504082553.20377-1-vsementsov@virtuozzo.com> <20210504082553.20377-2-vsementsov@virtuozzo.com> From: Max Reitz Message-ID: <712e9661-e296-b960-d6ca-9173f9ecb2f3@redhat.com> Date: Wed, 5 May 2021 14:37:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210504082553.20377-2-vsementsov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.693, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fam@euphon.net, kwolf@redhat.com, eesposit@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 04.05.21 10:25, Vladimir Sementsov-Ogievskiy wrote: > write-notifiers are used only for write-threshold. New code for such > purpose should create filters. > > Let's better special-case write-threshold and drop write notifiers at > all. (Actually, write-threshold is special-cased anyway, as the only > user of write-notifiers) Not noted here: That write-threshold.c is also reorganized. (Doesn’t seem entirely necessary to do right in this patch, but why not.) > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > include/block/block_int.h | 1 - > include/block/write-threshold.h | 9 +++++ > block/io.c | 5 ++- > block/write-threshold.c | 68 +++++++-------------------------- > 4 files changed, 25 insertions(+), 58 deletions(-) [...] > diff --git a/include/block/write-threshold.h b/include/block/write-threshold.h > index c646f267a4..7942dcc368 100644 > --- a/include/block/write-threshold.h > +++ b/include/block/write-threshold.h > @@ -59,4 +59,13 @@ bool bdrv_write_threshold_is_set(const BlockDriverState *bs); > uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs, > const BdrvTrackedRequest *req); > > +/* > + * bdrv_write_threshold_check_write > + * > + * Check, does specified request exceeds write threshold. If it is, send I’d prefer either “Check: Does the specified request exceed the write threshold?” or “Check whether the specified request exceeds the write threshold.” > + * corresponding event and unset write threshold. I’d call it “disable write threshold checking” instead of “unset write threshold”, because I don’t it immediately clear what unsetting the threshold means. > + */ > +void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset, > + int64_t bytes); > + > #endif [...] > @@ -122,3 +68,15 @@ void qmp_block_set_write_threshold(const char *node_name, > > aio_context_release(aio_context); > } > + > +void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset, > + int64_t bytes) > +{ > + int64_t end = offset + bytes; > + uint64_t wtr = bs->write_threshold_offset; > + > + if (wtr > 0 && end > wtr) { > + qapi_event_send_block_write_threshold(bs->node_name, end - wtr, wtr); OK, don’t understand why bdrv_write_threshold_exceeded() had two cases (one for offset > wtr, one for end > wtr). Perhaps overflow considerations? Shouldn’t matter though. > + bdrv_write_threshold_set(bs, 0); I’d keep the comment from before_write_notify() here (i.e. “autodisable to avoid flooding the monitor”). But other than that, I have no complaints: Reviewed-by: Max Reitz > + } > +} >