From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.2 required=3.0 tests=AWL,BAYES_00,BODY_8BITS, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 226001F461 for ; Thu, 16 May 2019 12:28:34 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=m6XuHCW7U4zLu5lM WVZNDVcdd9oEF97BmcaK6noz75Y1EHl7eOC9Fz3CKhuB00CpUX3SfZX6ATKSdoa5 onFt5/fs52cZabib31l3w8ootHIjiF2k570vJD1fA4NoMw+Hz+dE/jfsZyErJAJk SOMxOyyZ4d4N4YuG748WUMSua6M= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=a/WhAU02nUb0tCqXOtmfTZ fDeMY=; b=br4Gkc0zVXH0JMNpHc/AgQe9CAQhbZTeMEZBbKB2/AQxUdF8lcTIFu ZrrC2sUq2XZCbf6Jc+SF/5B5yzL0jh0OKbF2p/fjDBhzaHpUpoEcAOQC4XC/3xXl 0MgWVbE+udX25eQZjTRc9/gPa/m+y2cBBXw4BmLITnotILzioyBuM= Received: (qmail 64368 invoked by alias); 16 May 2019 12:28:31 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 63928 invoked by uid 89); 16 May 2019 12:28:31 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-ua1-f67.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Gajj8ji+IfvlJmFQG+M58tn9BaPxFKOlqk57otylZPo=; b=TbEYRrY8ANZ38p7YFjO3ytqxMRL0jdNzBeYZ7VV3U5nOn1umbfNt6i3Ma8C28Ak4++ cylsKzTPwJJn1sD0SfThLnC3Y5sY+fzwAx31zqQr6YW8VQ+tfTXk3Y4aPIthtqrFqK8n p17Ni3gslNWvz6AihVjWmv3B36cyUzgkXLdrAge+/x/Gsi6WtOege6OFNVVQQ6wsnchg QhCiPVOJqf43Y/xiJeC581NcQdCQKdzVBh2Q5U25p3BIdqhKXgRakAt+4UxqPa4UiY+X 9nmBqYOHTLpQjk71cClFPvvBJX7VqvOR1nclZrr9uTtLb0a0bJlP4CCeBWwZdLUs3qgd vVMQ== Subject: Re: Update kernel-features.h files for Linux 5.1 To: Arnd Bergmann Cc: GNU C Library References: <20190510102713.udgjb6ilygibgd5x@sghpc.golosunov.pp.ru> <77b2e1fd-7f91-5de3-6e33-e72f00f93544@linaro.org> <4d6d5aa8-e60b-b27d-f69f-17ae26b35bbc@linaro.org> From: Adhemerval Zanella Openpgp: preference=signencrypt Message-ID: <288dd545-5522-562e-ac6b-a63ef79dfe1d@linaro.org> Date: Thu, 16 May 2019 09:28:25 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit On 16/05/2019 08:34, Arnd Bergmann wrote: > On Thu, May 16, 2019 at 1:15 PM Adhemerval Zanella > wrote: >> On 16/05/2019 05:08, Arnd Bergmann wrote: >>> On Fri, May 10, 2019 at 5:07 PM Adhemerval Zanella >>> wrote: >>>> On 10/05/2019 07:27, Stepan Golosunov wrote: >>>>> 09.05.2019 в 23:00:37 +0000 Joseph Myers написал: >>>>>> Linux 5.1 adds missing syscalls to the syscall table for many Linux >>>>>> kernel architectures. This patch updates the kernel-features.h >>>>>> headers accordingly. I believe the statfs64 structure used by alpha >>>>>> matches what the new kernel syscalls use, but that should be reviewed >>>>>> carefully. >>>>>> >>>>>> Tested with build-many-glibcs.py. >>>>> >>>>> The newly added direct ipc syscalls are different from the old ones: >>>>> >>>>> 1. They do not accept IPC_64. This means that __IPC_64 should be set >>>>> to zero when new syscalls are used. And new syscalls can not be used >>>>> for compat functions like __old_semctl. >>>> >>>> So it seems we will need to conditionally set __IPC_64 based on kernel >>>> version. >>> >>> How so? I did not expect to see any libc change here at all, unless >>> you mean after you stop using sys_ipc(). >> >> The idea is if user configure a minimum kernel version of v5.1, >> sysvipc would use wire-up syscalls. So for sys_ipc the affected >> architectures calls with required IPC_64, and for wire-up syscalls >> IPC_64 is redefined accordingly. > > Ah, I see. Is there any real advantage in doing this now though? > It seems to save a few cycles for each of those syscalls when building > for linux-5.1+, but the cost is a significant increase in source code > complexity. Not really, however it gave me opportunity to clean up the sysvipc code a bit more. I changed the __IPC_64 default value to 0x0, which simplifies a bit new ports additions (no need to override the value); consolidates some implementation a bit more (s390 is an outlier regarding semtimedop); and we spot an compat issues on alpha. I am just checking everthing is ok on a 5.1 kernel before send it to review.