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 DC609C636D3 for ; Sun, 12 Feb 2023 18:20:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229604AbjBLSUO (ORCPT ); Sun, 12 Feb 2023 13:20:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbjBLSUM (ORCPT ); Sun, 12 Feb 2023 13:20:12 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DBBC1025E; Sun, 12 Feb 2023 10:20:11 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5B4E2B80CBF; Sun, 12 Feb 2023 18:20:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BACDC433EF; Sun, 12 Feb 2023 18:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676226009; bh=MJjysyKBHGe9JZ/bqgooxVcRfzQCFzHhpHVyrLvWeA4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=enQuMwuBn6D1txzxnlMuUu8ScrNWig9UjQGKD3652roF/zJR5ynT6DibKKroUQdNL SCnOxAZfTlMGflXLK8xXj6Wq85KudB0sH+5yPds/d+hsfy/A/RyFZfB4/9+L7ulH1n kHip0k1TGvb3iew8gX8mwxp1QJzdPZtiC0V1KSx1HY7N0kYpqlY95LeYSMfwVg/sz1 IUio0/iMp3+iSO6NepZVELn4vDb1I1ISnzWsPczD7EQssrLsUe/95qjbKvxTjyfjM4 pjGELgtKA8jQQQYKSr9UcKlJ9/uqLjtB9Cg41x4Ztl0j9cbt2LLI5ZB8LXWnUyJGgh WHnr6C8KhYIKg== Date: Sun, 12 Feb 2023 18:20:03 +0000 From: Conor Dooley To: Guenter Roeck Cc: Jisheng Zhang , Palmer Dabbelt , Paul Walmsley , Albert Ou , Anup Patel , Atish Patra , Heiko Stuebner , Andrew Jones , Conor Dooley , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org Subject: Re: [PATCH v5 00/13] riscv: improve boot time isa extensions handling Message-ID: References: <20230128172856.3814-1-jszhang@kernel.org> <20230212154333.GA3760469@roeck-us.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="LL9KTVybbDibeZ25" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --LL9KTVybbDibeZ25 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Feb 12, 2023 at 10:14:13AM -0800, Guenter Roeck wrote: > On 2/12/23 10:06, Conor Dooley wrote: > > On Sun, Feb 12, 2023 at 05:06:09PM +0000, Conor Dooley wrote: > > > On Sun, Feb 12, 2023 at 04:33:58PM +0000, Conor Dooley wrote: > > > > On Sun, Feb 12, 2023 at 03:59:59PM +0000, Conor Dooley wrote: > > >=20 > > > So as not to lead anyone up the garden path, let me correct myself: > > >=20 > > > > Hmm, so this appears to be us attempting to patch in alternatives w= here > > > > none actually exists - seemingly F & D. > > >=20 > > > And of course that's not true, riscv_has_extension_likely() now uses > > > alternatives as of: > > > bdda5d554e43 ("riscv: introduce riscv_has_extension_[un]likely()") > > >=20 > > > From a quick look, it just happens that the only users are F & D. > > >=20 > >=20 > > Samuel pointed out that this is a lockdep splat on irc. > > There's a patch on the list that removes the lockdep annotation > > entirely: > > https://patchwork.kernel.org/project/linux-riscv/patch/20230202114116.3= 695793-1-changbin.du@huawei.com/ > >=20 > > So ye, no surprises that it was config based! > >=20 > > Palmer posted a "better" fix for that lockdep warning a while ago: > > https://lore.kernel.org/all/20220322022331.32136-1-palmer@rivosinc.com/ > >=20 > > So we'd have to duplicate/reuse that for cpufeature/errata patching. > >=20 > >=20 >=20 > This does not (only) happen in stop_machine(). Yah, sorry I meant that it's the same lockdep splat as is being addressed there. The first patch deletes the lockdep stuff entirely, so removes the splat. I was thinking that we'd need to take Palmer's (IMO better) patch and do the same thing for patching alternatives, but I figure we can just take the text_mutex itself for alternatives & not have to dance around the lock. I'll go do that I suppose! --LL9KTVybbDibeZ25 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCY+kt0wAKCRB4tDGHoIJi 0lCHAP9dmIfODGeFB30mrFC0ZS7H8294Wq2cp9dIc6LMlnpd2AEAiBTRGyJfm/jN XVO7+oQ9i0CJT3HiApBW4j9H3mFCbgU= =gBzF -----END PGP SIGNATURE----- --LL9KTVybbDibeZ25--