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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C2FDC61DA4 for ; Mon, 6 Feb 2023 06:48:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EF3E96B0072; Mon, 6 Feb 2023 01:48:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E7CEA6B0073; Mon, 6 Feb 2023 01:48:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1D6B6B0074; Mon, 6 Feb 2023 01:48:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id BF38E6B0072 for ; Mon, 6 Feb 2023 01:48:09 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 9639C1C6326 for ; Mon, 6 Feb 2023 06:48:09 +0000 (UTC) X-FDA: 80435937498.27.C4633DB Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf30.hostedemail.com (Postfix) with ESMTP id E89D980007 for ; Mon, 6 Feb 2023 06:48:07 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=odUmwiZG; spf=pass (imf30.hostedemail.com: domain of gregkh@linuxfoundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675666088; a=rsa-sha256; cv=none; b=W+GoyfgWPgfN4lnJhcbduoADS56KoHngisP2wkNq/CW+WEN4LAaeZh9K0r59Dmrdlr30eb g/Os+3w+Km5UAiH6L/GzE63uga14kjsXgW7P3GH32tVZdC/Kn1RATd8GCww/QJosUfMPmv fsDDbYBToemdkNjGiWI9ULEZyL1tGjM= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=odUmwiZG; spf=pass (imf30.hostedemail.com: domain of gregkh@linuxfoundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675666088; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=IbZXHHLgBFY0fWN6vdfUx/7JsQpS03PgVQJBNUqUI9o=; b=Uke4UmhD1nxUs/pcHNlHPZ7d9vvPuWC1i4TJNyCNFLWkX4CZ1S8b43fzHcGFq6ekD5cou7 ugVv36m7rby9xQpzyImmUOn2/NL8NPBO5UANLZLR0RNxC8548Op3XFmqVbsqGa6Q1Hur87 8UFC6rgv7ZN0ymYsoIVaFXXqLzB1XZU= 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 dfw.source.kernel.org (Postfix) with ESMTPS id 9535160C6F; Mon, 6 Feb 2023 06:48:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77F51C433EF; Mon, 6 Feb 2023 06:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675666086; bh=1VtEB+g5PvA7JJDmummqrb9ZrXzYa3O18vA/KOro2kM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=odUmwiZGoifvDiADHA/k0+2HHMJV/ssZR9P3lWDe2Lnq5NdUUXBXu/kk/q2kIl/7Q U7PoC63WvzX5Y5N19cTwhiOGEmDydI+urVvcTPURLRX9zj+fq+Not27r73TqsTO/ga 9S72StcCmugISBEiYxSUNgRZX0s9Nc5AuwkzpIC0= Date: Mon, 6 Feb 2023 07:48:03 +0100 From: Greg Kroah-Hartman To: Hillf Danton Cc: Alan Stern , Tetsuo Handa , "Rafael J. Wysocki" , linux-mm@kvack.org, LKML , USB list , Linus Torvalds Subject: Re: Converting dev->mutex into dev->spinlock ? Message-ID: References: <917e1e3b-094f-e594-c1a2-8b97fb5195fd@I-love.SAKURA.ne.jp> <20230206025629.1786-1-hdanton@sina.com> <20230206064305.1838-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230206064305.1838-1-hdanton@sina.com> X-Rspam-User: X-Rspamd-Queue-Id: E89D980007 X-Rspamd-Server: rspam01 X-Stat-Signature: 8mx81ymdz9wz1xk6cu13cy6zhshjgqcx X-HE-Tag: 1675666087-925418 X-HE-Meta: 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 ghijrRVp j29rfWwiYu4Wk02aNQ6VSHj8obnKzhbhcoiHxVsIlbBfSVLNTdBVPhEVDLWPna7IE1UBGBgiFhjOmfdPVGschP+KNTKRo8nB84F9ng8QcIuFPqcKI9m3wbpKD/PJ0MhYu5/eMUwP2ZZ8CFWxouwA33cNabbCncN0A4Y9OzRR6AIKvICAOyAUBBDNCAA/f4Zy9AX5V191LQL48pxxT3rTW0q8xJGQgpUYxJ9Be5r37vjC5P/yXuDqWqwMbDmNz35d97BjFBCTw2goNq7jJsOE9uN5AO3/z40gxNpo0u7ou+QyEDhza5WznDuLGMk6nCoBFQjAv0oM+TvwUpzisbcJsNoa8RwIU5XDW2T7BMBmksqnG8glxB+V68tawOeqKBS3cEznO3OtTvuOdf5kqieMzqtbm2UH/ONsCHQ+Pw0aGg3vBxJ45m9eHs+aGtx0f/ZZptDH7sdV1K18DB9dgjzBVStXZs1SkrFWhXNV2 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Feb 06, 2023 at 02:43:05PM +0800, Hillf Danton wrote: > On Mon, 6 Feb 2023 06:17:03 +0100 Greg Kroah-Hartman > > On Mon, Feb 06, 2023 at 10:56:29AM +0800, Hillf Danton wrote: > > > On Sun, 5 Feb 2023 11:46:06 -0500 Alan Stern > > > > > > > > And by the way, by disabling lockdep validation I am declaraing that > > > > enabling it would cause an overwhelming number of false positives, > > > > > > Could you share 5 false positives you see upstream to help understand how > > > it is useless? > > > > Please see this other email in this thread: > > https://lore.kernel.org/r/Y98FLlr7jkiFlV0k@rowland.harvard.edu > > What lockdep warnings? Specific examples, please. Remove the one line of code, as per the patch in this thread, and boot with lockdep enabled and see what happens if you wish to see them yourself. thanks, greg k-h