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 DEA86C48BC4 for ; Fri, 23 Feb 2024 10:08:53 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=lesdaC3A; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Th5M84159z3vZk for ; Fri, 23 Feb 2024 21:08:52 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=lesdaC3A; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=bootlin.com (client-ip=217.70.183.193; helo=relay1-d.mail.gandi.net; envelope-from=herve.codina@bootlin.com; receiver=lists.ozlabs.org) Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Th5LB5Ndjz3vXr for ; Fri, 23 Feb 2024 21:08:00 +1100 (AEDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id 9A3A524000A; Fri, 23 Feb 2024 10:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1708682876; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5c3jkfiwWBVIVcLpQtxgvJnB9TnAlyKeMM5FmscF5j8=; b=lesdaC3AUqO4IhojWmi1I7Z8Y86vi8R00ZOyKv++IK4CwhLPLOgn5XY5k4oR3MF9KxG5bP FHh8Vwvv8ZqVP7QC7gAed27JRdYn4HIB7z1pIItzXg4YYNTrETeym5e/QwVk9lB36wh9tm JxbCR6BLtTMDJO9AvkEoN32a3DNz4gcCTqKL8Tr4ZDnrsyAQx7L0BHAgfYciUrRKAtWAd6 TbBK9YZKs7K2AT92OvKym9dtZqqCJBhxy0zzQxhyw1V+Tke2vFi33vAh1YiWLCw5Dgt4Bl LyPfMMvW0GnXiDCqRuf8EqRFC3wBpgyr9kKf/gl7Wy0DYjAFj74/A+0yraffPA== Date: Fri, 23 Feb 2024 11:07:52 +0100 From: Herve Codina To: Yury Norov , Andy Shevchenko Subject: Re: [PATCH v4 3/5] lib/bitmap: Introduce bitmap_scatter() and bitmap_gather() helpers Message-ID: <20240223110752.2329d3f0@bootlin.com> In-Reply-To: References: <20240222142219.441767-1-herve.codina@bootlin.com> <20240222142219.441767-4-herve.codina@bootlin.com> <20240222174959.7097c29b@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.2.0 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-GND-Sasl: herve.codina@bootlin.com 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: Andrew Lunn , Vadim Fedorenko , netdev@vger.kernel.org, Rasmus Villemoes , linux-kernel@vger.kernel.org, Eric Dumazet , Mark Brown , Thomas Petazzoni , Jakub Kicinski , Paolo Abeni , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Andy, Yury, On Thu, 22 Feb 2024 13:50:48 -0800 Yury Norov wrote: > On Thu, Feb 22, 2024 at 05:49:59PM +0100, Herve Codina wrote: > > Hi Andy, Yury, > > > > On Thu, 22 Feb 2024 17:39:27 +0200 > > Andy Shevchenko wrote: > > > > ... > > > > + * bitmap_scatter() for the bitmap scatter detailed operations). > > > > > > > + * Suppose scattered computed using bitmap_scatter(scattered, src, mask, n). > > > > + * The operation bitmap_gather(result, scattered, mask, n) leads to a result > > > > + * equal or equivalent to src. > > > > > > This paragraph... > > > > > > > + * The result can be 'equivalent' because bitmap_scatter() and bitmap_gather() > > > > + * are not bijective. > > > > > > > > > > + * The result and src values are equivalent in that sense that a call to > > > > + * bitmap_scatter(res, src, mask, n) and a call to bitmap_scatter(res, result, > > > > + * mask, n) will lead to the same res value. > > > > > > ...seems duplicating this one. > > > > > > I would drop the latter one. > > > > I would like to give details about the 'equivalent' in this scatter/gather case. > > If you would like - please do! :) > > > If Yury is ok, I can drop this last paragraph. > > The original bitmap_onto() description is 3 times longer, and barely > that descriptive. I'm OK with your working and especially pictures. > Right, I will keep my last paragraph in the next iteration. Regards, Hervé