From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 70AD83858C31 for ; Thu, 14 Mar 2024 09:02:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 70AD83858C31 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 70AD83858C31 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710406937; cv=none; b=DnncPVUPbD2KLgjBF1LEJpqkyA53hPepu5qownTGPEY8Kxa3gJJ/pPb3TzYN3fI+EhPqyH+SthVVn/DJkjAx/3H/0RN1OVZVIfeoVobHhTLtkELn58Ov57jxtLozsjZh0ZKaVH+bYFBjsDWU7N8+GUwHcyXSviNt+qGRShXrZ3I= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710406937; c=relaxed/simple; bh=JHXovnfMR1GmCC/U5cce1YOREwD/JOh6E6Q7ZW3SSls=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=A41eX8HhaV4Taz7Ca5TNadqCma5+uI/drQ751XkgB7SQMrabHYnrQTOr2Z0/9h+7G/cD+iNiacJYk/ZX9gjzTnEinkMzcj/H3N4mofY9+RkE6JrQS2NZYx3dPu3+WCaF6lP6Siq4J5egUEygsFZq5F967ZEoEboqbbh1FJy2cHk= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710406935; 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=CN94wooeXHKPNmyEfGD6i371oQueMMhusscSjDKVLDs=; b=LYyo2UR0/Swibb1Nu83QjKbwCUD0om2p6ZryZJzUt54UDmmHx6RZIeGyfpHvp2Vnfq2A9G 2a/ZOsW0qROKymLOawLHmcsfgqXrCV5gI/Fm4IDRZrmaLBHXBMq3mBZyGeaR3RTlrqqA1i cyFf0Ti/P5W3xc0LGnhGVMpLT9jMsQs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-604-NCvq7LRHOhuuVE7Sy9a0vA-1; Thu, 14 Mar 2024 05:02:12 -0400 X-MC-Unique: NCvq7LRHOhuuVE7Sy9a0vA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id B00138551F0; Thu, 14 Mar 2024 09:02:11 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.73]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A22D7492BD0; Thu, 14 Mar 2024 09:02:10 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Netto Cc: Szabolcs Nagy , Wilco Dijkstra , 'GNU C Library' Subject: Re: [PATCH] AArch64: Check kernel version for SVE ifuncs References: <319a4afc-3841-4532-8350-be16e296c251@linaro.org> <44aeef4b-1044-4be8-9f35-e592a1c26080@linaro.org> Date: Thu, 14 Mar 2024 10:02:09 +0100 In-Reply-To: <44aeef4b-1044-4be8-9f35-e592a1c26080@linaro.org> (Adhemerval Zanella Netto's message of "Wed, 13 Mar 2024 16:55:16 -0300") Message-ID: <87cyrxnq3y.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE 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: * Adhemerval Zanella Netto: > Yes, I understand this. My point it won't be possible to backport this > kernel fix to get the performance improvement of SVE routines without > hacking the glibc as well. It is not really a blocker, but I would > expect kernel to do proper advertise for such performance change that > might interfere with ifunc selection. Maybe we can add a tunable to > force SVE selection, but I don't have a strong opinion. I think the kernel change went into the other direction: it eliminated the SVE trap after system calls. Thanks, Florian