From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A7C181AC8; Thu, 15 Aug 2024 21:16:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723756602; cv=none; b=ggH43C4o0rhxbNKTLwKzrlUI8WoS5hTfMC+t4F9X2PD+C/j4RadBJSxLVZ84D1jJhWDf+1zLIAuMw/SZGpZwabkWOlk0F7cFaVh+SP13vVq0WahdUYIqrVDAF/fa3smCQSis5HavjnHPrrVXatFx3ppJSC9UKFLCK+VZKer6/6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723756602; c=relaxed/simple; bh=PBA4Ln8lIjVagUzDRvfyQYRjlu83b2/CSeXAl5ZAL8I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=njHJ7U70pjU7WGuGDijSR9sP4ZnSE2odoI8mRbL+Q27QF7oBrIedhnvl8497ew0+ZEkU4tMnFXU6UBdG2kFpFXvMSf+SLIUGCR2WhbKwOXzj6KE8/XF2WGnSAmMhXPd4r0Jmd2d/dOCsXQjwRNXPajFsa6uFOwXA/yuKtvhSV2c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=FHqBFdpM; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FHqBFdpM" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=wVrshdgc5r4mBDt3sLx4Vu72sbLxT+zdRw8VaO2LgwU=; b=FHqBFdpMR0fSUdDqEFPZ1ujvqt ZjOVAXoZcKmsBhvKFP2Bkm7pHlUIJ/Sa1yrQ0UKruvR7CPWMoALIhwtH8a1II/uiFHALHJasonaSP 15JC13KaliZ75mxBzCnAaPa6i5Bh5sN9i/haxtz9I1dSodd5wXWX3N4hvKkpZf1KNwMdS25f5HGhO LzqDd1wy8fNskrB7q7ViaVJSO8A0WpVzfUE8qWqjxtwaRCxib2gv7g3lKnCJKsYM5WH9SVxSkRsBP IH5sJlXLQliZZsfnk1JTlOfgcWz1Vjol/gXnpSfnAz/JgcvxlOewEYav8qt91ydmucqj4hGa07Kal zuXLdElA==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sehpb-00000002b12-2mPQ; Thu, 15 Aug 2024 21:16:27 +0000 Date: Thu, 15 Aug 2024 22:16:27 +0100 From: Matthew Wilcox To: Roman Gushchin Cc: Shakeel Butt , Andrew Morton , Johannes Weiner , Michal Hocko , Muchun Song , "T . J . Mercier" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Meta kernel team , cgroups@vger.kernel.org, Michal Hocko Subject: Re: [PATCH v2] memcg: replace memcg ID idr with xarray Message-ID: References: <20240815155402.3630804-1-shakeel.butt@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Aug 15, 2024 at 07:31:43PM +0000, Roman Gushchin wrote: > There is another subtle change here: xa_alloc() returns -EBUSY in the case > of the address space exhaustion, while the old code returned -ENOSPC. > It's unlikely a big practical problem. I decided that EBUSY was the right errno for this situation; #define EBUSY 16 /* Device or resource busy */ #define ENOSPC 28 /* No space left on device */ ENOSPC seemed wrong; the device isn't out of space.