From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from crocodile.elm.relay.mailchannels.net (crocodile.elm.relay.mailchannels.net [23.83.212.45]) by sourceware.org (Postfix) with ESMTPS id 1F6E53871F9C for ; Tue, 6 Dec 2022 19:25:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1F6E53871F9C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gotplt.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 3FD667617DD; Tue, 6 Dec 2022 19:25:57 +0000 (UTC) Received: from pdx1-sub0-mail-a307.dreamhost.com (unknown [127.0.0.6]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id B12B7761AD1; Tue, 6 Dec 2022 19:25:56 +0000 (UTC) ARC-Seal: i=1; s=arc-2022; d=mailchannels.net; t=1670354756; a=rsa-sha256; cv=none; b=oAQ3bmLW4Am9GprirNMCDvcdZdse03ggDGAUi7Kc2+AI9Rzm1idN06lXEHVfg/UkpsI5NJ c5/+8GP2hKRyoos/oS6HOyTLnOsEC3SIENHI0yZ9B8sbdVXKjX+gAvo0UgA6MFn+Wr7YkQ KZnvf5kG7WtlO4dFz9joo1dSTrYRJSgF9CfiGLrQ8vp0M8H5ynRwhLaOkX0h80OA61brT3 qQwqd40nlHTRz1ihZAqObM1gy/FOUV7J+cJSdC16nqHkeWpbUNafokOtS06GkoP3cVOt3h 5ClSt8UtlK4xGLYFP8KNJS/WcVT/nw/FUMfOCNoP6RepnDzMK68sA+RTEGeHmw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=mailchannels.net; s=arc-2022; t=1670354756; 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:dkim-signature; bh=G+8NREl9cv2clThz9aSEGyq85Oc/NVhDv7WVk6KYHGA=; b=IXfpMYrmlvzIzJN5uUftIwkEz2b+Whq6lRLtDYrCrcrA1Geco+dRQbGFtP2hlxKCFh+Eae 3YTnG8DSDNNPP2bOjh/ku8epT7fmKRTEzzg3gQ/WaXiMDXC40GeW5Y4llRiAK4cOo/7kY4 y7Ov0Uq5GgaGxRiM2SO3IfHdDIa+kmJR+rTmMPQSkFArDuX8J7IZQ94ekwIw3jacJ09gnn dOhxvBBVpsZYS7rIaEev+m8CBPozRCNuzyCScl/Oc3HpHv7oMRcXFoYZ3wW7zsV4Bnd55C 9vsIXouTGow6upRgmXmujWeT5zCIgMapcE8z7RN0wGWgRP4O6JTDPz7bsTyINg== ARC-Authentication-Results: i=1; rspamd-d48c5ddb-qznmr; auth=pass smtp.auth=dreamhost smtp.mailfrom=siddhesh@gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Glossy-Trouble: 4f8163b660804543_1670354757001_1754011242 X-MC-Loop-Signature: 1670354757001:4203744302 X-MC-Ingress-Time: 1670354757000 Received: from pdx1-sub0-mail-a307.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.103.24.106 (trex/6.7.1); Tue, 06 Dec 2022 19:25:56 +0000 Received: from [192.168.0.182] (bras-base-toroon4834w-grc-23-76-68-24-147.dsl.bell.ca [76.68.24.147]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a307.dreamhost.com (Postfix) with ESMTPSA id 4NRVkp6pWNzK4; Tue, 6 Dec 2022 11:25:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gotplt.org; s=dreamhost; t=1670354755; bh=G+8NREl9cv2clThz9aSEGyq85Oc/NVhDv7WVk6KYHGA=; h=Date:Subject:To:Cc:From:Content-Type:Content-Transfer-Encoding; b=qyh/RIZrw7LqxqM+NMb2XyEXaBFgTiph+8Ud49+RYAxd6ww3a5tgsPPRUEnK7Gbwf U9I3h1fDrIYCJZH9E9ABxsh5L4o2rL4M+hoGxW+2cCcwkyOMpRB3BBnic6dUPGPTfP IQJjlYH+x09vjchZXMNsN+pcH63Ej5VhIKRnn0Qr0k1rfUAwy4aMuHuYa5tw/3sT+d XC/4tB6T6d3je1b4knsFCnerI36hHKO/oOd+kEK9FQHswpB9Tst6jiYFpTz+NjoFWh cYfxddYYSkk7cLmuoPUY7XtwBIlQ/y1SAp2tMvsz0Ytuj2G2rUoUAa8qGpSbIFh+L3 Q6mjAm5lJgddA== Message-ID: Date: Tue, 6 Dec 2022 14:25:53 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [RFC] Supporting malloc_usable_size Content-Language: en-US To: Florian Weimer , Zack Weinberg via Libc-alpha Cc: Zack Weinberg References: <20221124213258.305192-1-siddhesh@gotplt.org> <87sfhyrp19.fsf@igel.home> <87o7smrnlh.fsf@igel.home> <87pmd2rnce.fsf@oldenburg.str.redhat.com> <5758633c-9989-e463-0eb6-33f483439289@owlfolio.org> <87359tpp1m.fsf@oldenburg.str.redhat.com> From: Siddhesh Poyarekar In-Reply-To: <87359tpp1m.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3031.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 2022-12-05 15:35, Florian Weimer via Libc-alpha wrote: > I think it's a backwards-incompatible change. The existing manual page > documents the function as MT-Safe. > > With this new policy, I don't think malloc_usable_size is useful for > anything at all, and we can just deprecate it (with a deprecation > warning message) and eventually remove it from linking (after > considering the impact on replacement malloc implementations, but I > don't think it will be problematic). We don't have consensus on deprecation unfortunately. DJ is of the opinion that the limited use (knowing the usable size but not being able to do anything with it) may be useful enough for some programs. With that position, making it clear that the extra space is never safely usable and then just leaving it at that is probably the least worst out. Sid