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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 74FE8EB64D7 for ; Tue, 13 Jun 2023 21:10:43 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=ZwHrH/Ut; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Qgh6T5RFBz30hw for ; Wed, 14 Jun 2023 07:10:41 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=ZwHrH/Ut; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=rppt@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4Qgh5P6XPhz2xpl for ; Wed, 14 Jun 2023 07:09:45 +1000 (AEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 459FD63B01; Tue, 13 Jun 2023 21:09:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1CA2C433C0; Tue, 13 Jun 2023 21:09:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686690580; bh=CnDPIeLogwBWCfXwDFCGYSnn6freMhcPiMKmnauZmK8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZwHrH/UtQy5gtJuV6CZdRxLuHzTaAkiUGIx/JgEU65AMLsBIKZ0sWdlw1vTEQYgdy gSLYt19YIoeRBe5zYzLlgTuRTMMo3kgRmlRYZUwN9+y0DX2gj67q8Dp8pJtQUo0gHp Oy60KuQPQMSSexOGqUQrMmT3Fgb1GBewXzaMMxDEmcoyUN9bNnKzEk/bEsVagentbs IrjokONRoY0TE+yzqvQqq0avTQyKOfbb7gZycLtP7znx6sVR7tnvKBFHLqFKSVwEs2 kIA6GPsL9JTaWmKMWc1Wdyo1oerK/huG9zsVu6RfIYfLEAg8ULTJ9IL3DRtm5ddTXF JrMlJp241w1cA== Date: Wed, 14 Jun 2023 00:09:00 +0300 From: Mike Rapoport To: Kent Overstreet Subject: Re: [PATCH 00/13] mm: jit/text allocator Message-ID: <20230613210900.GV52412@kernel.org> References: <20230601101257.530867-1-rppt@kernel.org> <20230605092040.GB3460@kernel.org> <20230608184116.GJ52412@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Catalin Marinas , linux-mips@vger.kernel.org, Song Liu , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Will Deacon , linux-s390@vger.kernel.org, Helge Deller , Huacai Chen , Russell King , "Naveen N. Rao" , linux-trace-kernel@vger.kernel.org, Heiko Carstens , Steven Rostedt , loongarch@lists.linux.dev, Thomas Gleixner , Andrew Morton , linux-arm-kernel@lists.infradead.org, Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Dinh Nguyen , Luis Chamberlain , Palmer Dabbelt , bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "David S. Miller" , linux-modules@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Jun 13, 2023 at 02:56:14PM -0400, Kent Overstreet wrote: > On Thu, Jun 08, 2023 at 09:41:16PM +0300, Mike Rapoport wrote: > > On Tue, Jun 06, 2023 at 11:21:59AM -0700, Song Liu wrote: > > > On Mon, Jun 5, 2023 at 3:09 AM Mark Rutland wrote: > > > > > > [...] > > > > > > > > > > Can you give more detail on what parameters you need? If the only extra > > > > > > > parameter is just "does this allocation need to live close to kernel > > > > > > > text", that's not that big of a deal. > > > > > > > > > > > > My thinking was that we at least need the start + end for each caller. That > > > > > > might be it, tbh. > > > > > > > > > > Do you mean that modules will have something like > > > > > > > > > > jit_text_alloc(size, MODULES_START, MODULES_END); > > > > > > > > > > and kprobes will have > > > > > > > > > > jit_text_alloc(size, KPROBES_START, KPROBES_END); > > > > > ? > > > > > > > > Yes. > > > > > > How about we start with two APIs: > > > jit_text_alloc(size); > > > jit_text_alloc_range(size, start, end); > > > > > > AFAICT, arm64 is the only arch that requires the latter API. And TBH, I am > > > not quite convinced it is needed. > > > > Right now arm64 and riscv override bpf and kprobes allocations to use the > > entire vmalloc address space, but having the ability to allocate generated > > code outside of modules area may be useful for other architectures. > > > > Still the start + end for the callers feels backwards to me because the > > callers do not define the ranges, but rather the architectures, so we still > > need a way for architectures to define how they want allocate memory for > > the generated code. > > So, the start + end just comes from the need to keep relative pointers > under a certain size. I think this could be just a flag, I see no reason > to expose actual addresses here. It's the other way around. The start + end comes from the need to restrict allocation to certain range because of the relative addressing. I don't see how a flag can help here. -- Sincerely yours, Mike.