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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8BE27C0218F for ; Thu, 30 Jan 2025 14:26:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tdVU1-0006sT-Ug; Thu, 30 Jan 2025 09:25:30 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tdVTz-0006rS-3j for qemu-devel@nongnu.org; Thu, 30 Jan 2025 09:25:27 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tdVTx-0000SE-Bm for qemu-devel@nongnu.org; Thu, 30 Jan 2025 09:25:26 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738247122; 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=gXPTT1/MPlCjPMkpkTwEDTSKl8MPoKCI3dKlcc6iGqY=; b=ISaCN0Z/MpeFc39gRRqKEESMq1YjF+/aIL8XVHVbgBqOcem61fLNc8eDr/oRkc5N2mnoSv hWdqlWdpGhzjiQoXgzdqmP68Jj4TEjG2Bx88qFQn0ILRyipide8Dzk6fKGqnZ2dw/Vw3dD PyYsEem5Ep/udeR3Lqun3BjaXneBANk= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-241-IByZWIl_Pp2pDxYTFPLUiw-1; Thu, 30 Jan 2025 09:25:20 -0500 X-MC-Unique: IByZWIl_Pp2pDxYTFPLUiw-1 X-Mimecast-MFC-AGG-ID: IByZWIl_Pp2pDxYTFPLUiw Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2D5CE1801F1F for ; Thu, 30 Jan 2025 14:25:19 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.71]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E5C2A18008F4 for ; Thu, 30 Jan 2025 14:25:18 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1E5E021E6A28; Thu, 30 Jan 2025 15:25:16 +0100 (CET) From: Markus Armbruster To: =?utf-8?Q?C=C3=A9dric?= Le Goater Cc: qemu-devel@nongnu.org, Alex Williamson , Markus Armbruster Subject: Re: [PATCH v2 1/9] util/error: Introduce warn_report_once_err() In-Reply-To: <20250130134346.1754143-2-clg@redhat.com> (=?utf-8?Q?=22C?= =?utf-8?Q?=C3=A9dric?= Le Goater"'s message of "Thu, 30 Jan 2025 14:43:38 +0100") References: <20250130134346.1754143-1-clg@redhat.com> <20250130134346.1754143-2-clg@redhat.com> Date: Thu, 30 Jan 2025 15:25:16 +0100 Message-ID: <87msf8xttf.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.3, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org C=C3=A9dric Le Goater writes: > Depending on the configuration, a passthrough device may produce > recurring DMA mapping errors at runtime and produce a lot of > output. It is useful to report only once. > > Cc: Markus Armbruster > Signed-off-by: C=C3=A9dric Le Goater > --- > include/qapi/error.h | 5 +++++ > util/error.c | 9 +++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/include/qapi/error.h b/include/qapi/error.h > index 71f8fb2c50eee9a544992d0c05263c9793956fe1..b6ea274882b9788b64d4bb213= c3458d7c674a881 100644 > --- a/include/qapi/error.h > +++ b/include/qapi/error.h > @@ -448,6 +448,11 @@ void error_free_or_abort(Error **errp); > */ > void warn_report_err(Error *err); >=20=20 > +/* > + * Convenience function to call warn_report_err() once. > + */ > +void warn_report_once_err(Error *err); > + > /* > * Convenience function to error_report() and free @err. > * The report includes hints added with error_append_hint(). > diff --git a/util/error.c b/util/error.c > index e5e247209a9e0796074a9794f5598325f22f8d35..b8a211cccaa609a93091b8631= 6144a0ad0a02662 100644 > --- a/util/error.c > +++ b/util/error.c > @@ -247,6 +247,15 @@ void warn_report_err(Error *err) > error_free(err); > } >=20=20 > +void warn_report_once_err(Error *err) > +{ > + static bool print_once_; > + if (!print_once_) { > + warn_report_err(err); > + print_once_ =3D true; > + } > +} Any particular reason for the trailing _ in @print_once_? The first warning suppresses all subsequent warnings, even if they're completely different. PATCH 5 uses this to emit a (rather cryptic) warning about unexpected mappings once. If we later add another use elsewhere, these uses will suppress each other. Is this what we want? The related function warn_report_once_cond() takes the flag as a parameter. Only the calls using the same flag suppress each other. > + > void error_reportf_err(Error *err, const char *fmt, ...) > { > va_list ap;