From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DE20815D1; Sun, 2 Nov 2025 06:51:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762066294; cv=none; b=BfZdThAK6/tNkqRTU3419hseL3NLTbOgIbdYx6rmq9iGjhjP838zzCu1jnOTLCa0c7UW7GD+1w/0TnxQ9EnwGaQWDxdvNnJEVw8uflqG5h5kw8YnuSyWC1Nr+1SmDR8UcduJF5iJ8pKg+Lsnzpg9hYdftprO6t2YIyAkIk+eaF0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762066294; c=relaxed/simple; bh=LiEsqySHdTNYoNAeeFwBBm/8FtkxDtaFLj1JlFEIwUY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JMJVHIUr0wGEOgoQlf/QJn/Mu+CVKGvYzzatRE6+GRdNqYkurxgAsZe24cJpUPkjbgkdyaMRMiXlrarHXPN0KZM5z8ZnWv3NLPh7bIb6cpVw1KvAJDdnMkvk/g3pcxFo7Hl8jsOLLqHasnmkET04cpGNmYGjGtfy3HIeZgSsMiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vco4K2eV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vco4K2eV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABC90C4CEF7; Sun, 2 Nov 2025 06:51:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762066293; bh=LiEsqySHdTNYoNAeeFwBBm/8FtkxDtaFLj1JlFEIwUY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Vco4K2eVYGfYGyg5YaHsmWN+3k6nNiSCNBYy6ngq88ATZov79V6nUDRzIi5gwzstW Xe7q49t6AGV0dD46I6vdQAJAcYLbbMv3RM6KVHqgIHtILpg4//ZwtHtO2eM64ocX/u waAtNhTJ6/rZKk9j1bXufCWyDqAlo2vSH5JRjOVPC5m5FhVh3YZ2CCeUyKe6CR2WPC H6pViBJAdyPUW24cVSC2qToLalSQRX9J6o0/2Dex+E9Bw3upHJxQzt0exEnHFECSUN oWp8B654jSXWaDNW7NlNhsKGOuTWNqowQUgT3P23de8tG70lFk+sAVQcQlkvs8q8xl udORXqwFbHOkw== Date: Sun, 2 Nov 2025 08:51:24 +0200 From: Mike Rapoport To: Pasha Tatashin Cc: akpm@linux-foundation.org, brauner@kernel.org, corbet@lwn.net, graf@amazon.com, jgg@ziepe.ca, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, masahiroy@kernel.org, ojeda@kernel.org, pratyush@kernel.org, rdunlap@infradead.org, tj@kernel.org, yanjun.zhu@linux.dev Subject: Re: [PATCH v9 4/9] memblock: Unpreserve memory in case of error Message-ID: References: <20251101142325.1326536-1-pasha.tatashin@soleen.com> <20251101142325.1326536-5-pasha.tatashin@soleen.com> 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: <20251101142325.1326536-5-pasha.tatashin@soleen.com> On Sat, Nov 01, 2025 at 10:23:20AM -0400, Pasha Tatashin wrote: > If there is an error half way through KHO memory preservation, we should > rollback and unpreserve everything that is partially preserved. > > Signed-off-by: Pasha Tatashin > Suggested-by: Pratyush Yadav Reviewed-by: Mike Rapoport (Microsoft) with a small nit below. > --- > mm/memblock.c | 73 ++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 58 insertions(+), 15 deletions(-) > > diff --git a/mm/memblock.c b/mm/memblock.c > index e3bef9b35d63..f527ad1ca682 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -2445,29 +2445,60 @@ int reserve_mem_release_by_name(const char *name) ... > static int __init prepare_kho_fdt(void) > { > - int err = 0, i; > struct page *fdt_page; > void *fdt; > + int err; > > fdt_page = alloc_page(GFP_KERNEL); > - if (!fdt_page) > - return -ENOMEM; > + if (!fdt_page) { > + err = -ENOMEM; > + goto err_no_fdt_page; Please rename the label to describe what the goto does, say, err_report. I believe it can be a fixup on top after Andrew merges these. ... > +err_remove_subtree: > + kho_remove_subtree(fdt); > +err_unpreserve_fdt: > + kho_unpreserve_pages(fdt_page, 1); > +err_free_fdt: > + put_page(fdt_page); > +err_no_fdt_page: > + pr_err("failed to prepare memblock FDT for KHO: %d\n", err); > > return err; > } > -- > 2.51.1.930.gacf6e81ea2-goog > -- Sincerely yours, Mike.