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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=unavailable 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 007C5C282CE for ; Wed, 22 May 2019 18:23:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0D312173E for ; Wed, 22 May 2019 18:23:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="goDtFo0R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729528AbfEVSXX (ORCPT ); Wed, 22 May 2019 14:23:23 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:34754 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728272AbfEVSXX (ORCPT ); Wed, 22 May 2019 14:23:23 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x4MIJ5uZ071020; Wed, 22 May 2019 18:22:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=r5KZMuAu+51JUTI2ohhapWR6r+UgqS3aDYLLXOt7kLM=; b=goDtFo0Rr/Ds1O+vpv8kzreIVzaXr2FwgjQ/MipPKL+JxYC4bAn329mQEOpa6Ky7VBjy qpfzJWdvOvMbMACb6c8cVqsHSgZYWTsM7gYnJHSnNNXza+L3wAqSLhgIClBequuaoZ8R a9BJ9lgJHsqs/lfkaZIPiW1Y6v8zzOGISsxwZkr/ceVxjfTCKt5g3e2RzyY2ytzJ969Z Iuo7oTzQVEog543lhQ9fVgaAtHZk5LYKyrndey6nLACYxGLT4PdWq5BCteyBAmeFELyO 8RwA3ln39aSxeoeWZBCEek/X1VJaXZnLIt0CWl/nJ5QEOVuZdpe1DrT+4/6JXZhu9znF 9g== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 2smsk55syx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 22 May 2019 18:22:25 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x4MILhUW043670; Wed, 22 May 2019 18:22:25 GMT Received: from pps.reinject (localhost [127.0.0.1]) by userp3020.oracle.com with ESMTP id 2smsgv13ax-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 22 May 2019 18:22:25 +0000 Received: from userp3020.oracle.com (userp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x4MIMOoo045618; Wed, 22 May 2019 18:22:24 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2smsgv13aq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 22 May 2019 18:22:24 +0000 Received: from abhmp0022.oracle.com (abhmp0022.oracle.com [141.146.116.28]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x4MIMI50023367; Wed, 22 May 2019 18:22:18 GMT Received: from localhost (/10.159.211.99) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 22 May 2019 18:22:17 +0000 Date: Wed, 22 May 2019 14:22:15 -0400 From: Kris Van Hees To: Peter Zijlstra Cc: Alexei Starovoitov , Kris Van Hees , netdev@vger.kernel.org, bpf@vger.kernel.org, dtrace-devel@oss.oracle.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, acme@kernel.org, ast@kernel.org, daniel@iogearbox.net Subject: Re: [RFC PATCH 00/11] bpf, trace, dtrace: DTrace BPF program type implementation and sample use Message-ID: <20190522182215.GO2422@oracle.com> References: <201905202347.x4KNl0cs030532@aserv0121.oracle.com> <20190521175617.ipry6ue7o24a2e6n@ast-mbp.dhcp.thefacebook.com> <20190522142531.GE16275@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190522142531.GE16275@worktop.programming.kicks-ass.net> User-Agent: Mutt/1.5.23 (2014-03-12) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9265 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905220128 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, May 22, 2019 at 04:25:32PM +0200, Peter Zijlstra wrote: > On Tue, May 21, 2019 at 10:56:18AM -0700, Alexei Starovoitov wrote: > > > and no changes are necessary in kernel/events/ring_buffer.c either. > > Let me just NAK them on the principle that I don't see them in my inbox. My apologies for failing to include you on the Cc for the patches. That was an oversight on my end and certainly not intentional. > Let me further NAK it for adding all sorts of garbage to the code -- > we're not going to do gaps and stay_in_page nonsense. Could you give some guidance in terms of an alternative? The ring buffer code provides both non-contiguous page allocation support and a vmalloc-based allocation, and the vmalloc version certainly would avoid the entire gap and page boundary stuff. But since the allocator is chosen at build time based on the arch capabilities, there is no way to select a specific memory allocator. I'd be happy to use an alternative approach that allows direct writing into the ring buffer. Thanks, Kris