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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D776C433EF for ; Wed, 2 Feb 2022 18:11:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238368AbiBBSLB (ORCPT ); Wed, 2 Feb 2022 13:11:01 -0500 Received: from wnew2-smtp.messagingengine.com ([64.147.123.27]:43791 "EHLO wnew2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229800AbiBBSLA (ORCPT ); Wed, 2 Feb 2022 13:11:00 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailnew.west.internal (Postfix) with ESMTP id 773B72B002FF; Wed, 2 Feb 2022 13:10:58 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Wed, 02 Feb 2022 13:10:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm2; bh=BzKbLARq0BSnJcyeCRXnM9y5FOWw5F/q2SIlEb vvUnA=; b=ZlB8ag1vlar94J3JIbaoR2kXx0u5H4ra8Sjfw4n3q3CCboC+1wWCB5 Sil9FMGVAVjvW9ALaqFkT7TjBKjQjEYXIwngJOGRFEDclHRUlbb5V+mcW1bdyX/y X3v8uK5tze3wQquixUA90I/KgYQeqmMAJt7DE3+IHxU8qftBsY1UI/+YofwLKNVI QsnT0tQ37awOLDS0XJmVk7CGagdBTkPiPhvi0/+HdPsnyLzfsqWlxnjOl1gGYDEx 6GdSlO+O0zqCj9/7Io0++wLUKw0eThXoLxGh5Kz4NP8Z1buKEbZL22UUgnkTJB1I Jz9y7CByX94WIGns6NW5RNDNBuhHAZ7Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=BzKbLARq0BSnJcyeC RXnM9y5FOWw5F/q2SIlEbvvUnA=; b=j6XyjRhrAdRmn42tfpWzYZnxr/tR5NmNQ lAVeQ9GP+9I8FJUadv3FsosQl3pJ/MGaYw5GRb1tluNtJ/q3Vbmf9QJ4tTu+8/vL Ecu9nq0OKFO+G0OBbED0NlqmIGh7H8b3DjOVZ+auNFEyCIZc3cokMtSMdtON29YC c00JcIC3f9NF+L7Dep999cildR8hzlZTO/hxcI9wBdNtVVaFOghaBYpFAjZZuMKG JueZlGtY4rzXZeDr3HOod25MgrGNVBDdKW5bKW7co58ia0FudOcYhTlZIfVvR4Dc S5CQIypYApmYekGlWYKrDMdxPZ0iSH+sPI7i9hp9/4LjRMQ2JIiMw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrgeehgddutdelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne gfrhhlucfvnfffucdljedtmdenucfjughrpeffhffvuffkfhggtggujgesthdtredttddt vdenucfhrhhomhepffgrnhhivghlucgiuhcuoegugihusegugihuuhhurdighiiiqeenuc ggtffrrghtthgvrhhnpeeuuddvjeefffelgfeuveehfeegfeetfeetueduudfhudfhheev leetveduleehjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfh hrohhmpegugihusegugihuuhhurdighiii X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 2 Feb 2022 13:10:49 -0500 (EST) Date: Wed, 2 Feb 2022 10:10:47 -0800 From: Daniel Xu To: Luis Chamberlain Cc: Nick Alcock , bas smit , =?utf-8?B?VG9tw6HFoQ==?= Glozar , Ast-x64 , Viktor Malik , Jiri Olsa , jeyu@kernel.org, masahiroy@kernel.org, linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, arnd@arndb.de, akpm@linux-foundation.org, eugene.loh@oracle.com, kris.van.hees@oracle.com Subject: Re: [PING PATCH v7] kallsyms: new /proc/kallmodsyms with builtin modules Message-ID: <20220202181047.frwirxdpufwzkbv3@kashmir.localdomain> References: <20211216201919.234994-1-nick.alcock@oracle.com> <878rvk7uv2.fsf@esperi.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Luis, Nick, On Tue, Feb 01, 2022 at 07:09:23PM -0800, Luis Chamberlain wrote: [...] > > I don't see much traction based on what you have said on dtrace > on anything other than Oracle Linux stuff, it would be nice if bpftrace > folks were excited about your changes and we had support for that > there. I took a quick look at the v7 cover letter (I'll take a look at discussion from previous versions later if I get time) and it's not immediately obvious to me why a stable mapping is beneficial. Nick, could you elaborate why it's beneficial for dtrace to have a stable mapping? For what it's worth, bpftrace uses /proc/kallsyms rather rarely. bpftrace relies on perf_event_open()'s config1 parameter to resolve kernel symbol name to address for kprobe attachment. /proc/kallsyms is mostly used to resolve kaddr() calls in bpftrace scripts. Kernel symbol size information would be useful, though. bpftrace currently uses the vmlinux ELF to acquire that information. [...] Thanks, Daniel