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 4CD2F33A014 for ; Tue, 20 Jan 2026 18:37:17 +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=1768934238; cv=none; b=n1Pe0CkCmkFVSg2utTxXQn0V547hmLxtDn8yIb/bnEFSvDhIneARAeuatjUmG3ilZCwC8G94zX0vitez4rn2JPbvh8nmmpOXIh8cRysEYFovIv9Tg8321MLnRljUIOFdb/YUAnnQwVhsmu+HqR2EyTCdqLiOl/F02OOWeM5aVV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768934238; c=relaxed/simple; bh=qMsPsLKr8lsKfYWwVgXUWfhbGnBcx6jUKbbl7LEcQak=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=g9H6RfMBLSf7cuLxTdvCWvS6i7I3UmE9djTPU2jGv4iYfjayowG/WINj9kokPW7jdcVjraLZTG92VfOxMQPE44+fpThC33mUjCsT6ix6MtpFolxZvI/BC9ArB9rM+sTfJP62E4vs5aqHjoM/Qywtnh2zQ0sVY6sRe5prMDsEDDY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nRcoUS6s; 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="nRcoUS6s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C598C16AAE; Tue, 20 Jan 2026 18:37:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768934237; bh=qMsPsLKr8lsKfYWwVgXUWfhbGnBcx6jUKbbl7LEcQak=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=nRcoUS6sAu6+BgNMiYePK91g1ZaWzvwxv7IPVSWT7+mEBsipRiebKmFM/UAH0eXpC 9SE9Xl+mi1vH/JrUI9JiIU3rkScWHMsXFjG0cuOUR+4bC8x63o8LELmLFV5BYdk+Zp a/0CyanVVAAizhMAP2hYSqqIVzn+aocGIxop3dQXKWYOIF/C+dBcJb1q5beBRmGS9w vKcapO/vc8FBqDBtOLn+DaBBpyRgXxbT1Q0YrCGhJc+H5II6chN5mbowEOldzZh94S bk7yQKAL06Vj4wAjmCWmEynUSR6woff0aLxofTsDD6UsGKzT4L4CymQ63F2/5/QmwO eTYDKs9FcfvUw== From: Pratyush Yadav To: Evangelos Petrongonas Cc: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , "Alexander Graf" , Jason Miu , , , , Subject: Re: [PATCH v2] kho: skip memoryless NUMA nodes when reserving scratch areas In-Reply-To: <20260120175913.34368-1-epetron@amazon.de> (Evangelos Petrongonas's message of "Tue, 20 Jan 2026 17:59:11 +0000") References: <20260120175913.34368-1-epetron@amazon.de> Date: Tue, 20 Jan 2026 18:37:14 +0000 Message-ID: <2vxzecnkceqt.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, Jan 20 2026, Evangelos Petrongonas wrote: > kho_reserve_scratch() iterates over all online NUMA nodes to allocate > per-node scratch memory. On systems with memoryless NUMA nodes (nodes > that have CPUs but no memory), memblock_alloc_range_nid() fails because > there is no memory available on that node. This causes KHO initialization > to fail and kho_enable to be set to false. > > Some ARM64 systems have NUMA topologies where certain nodes contain only > CPUs without any associated memory. These configurations are valid and > should not prevent KHO from functioning. > > Fix this by only counting nodes that have memory (N_MEMORY state) and > skip memoryless nodes in the per-node scratch allocation loop. > > Signed-off-by: Evangelos Petrongonas Reviewed-by: Pratyush Yadav [...] -- Regards, Pratyush Yadav