From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 AA4FC377567; Mon, 11 May 2026 09:13:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778490784; cv=none; b=SAX6rvl3+PwXMkDTviFfyjXv8pheUnoe9GKW4xojP6L+Mu5FlBkdbnklHBHhGbVt8EdvSuRl+mctcMkMsaXdDsLApOytFC7lMmASmHEavY4WOtysW7wkRpsyLLTCZGXR45vVOuN3VUS0KAIa9LsUVw5TKSxQss7XoBRRE3qVh8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778490784; c=relaxed/simple; bh=v+NVvuMtu0+rgssi+Nf/wQoj/MpnCEhZR447leF12tY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bmQ9OrU/UZefRhBxrUMrlM+FkOmiEJOoQZZd3QSWfE7SDGvWIRSFbbK7a0xwSx5IAliyYUOC8lTfVzt16EH9/Ou4sIj2RSa0wJvO1nDgvzhVkPU3mKxaITN7Djf2AJGPYhmvNH4+65eBnUapmkomDnz3Xezw9ZRNLW1TE2jytL4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=Dhd0esCf; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="Dhd0esCf" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 64B5J9RQ2454484; Mon, 11 May 2026 09:12:32 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=7Zcp0k Wb+Anwe2WoWtnjD3EG2vBXgnnNuj3KIcfeAAM=; b=Dhd0esCf1iXuiU/vzkh1iY sm9iZRZm5mb83web4eqRkiZES1bqScKUuBM7huhXAaNpyQHmzFsy9pP15mV7c1XA yLFU7zv/HoO7sYheoXuqwV+8iM/hFFKVh+nsWLebceVlS4U06QUVIJNIvt8kATp6 gvFiQf2uTE8GP0NUbQ+PMnDfyZUzwbJYe2T5OFux1SXNAtEXX+st5VQjaBq9iBf2 1fkCq1HauNrmCRjhCCiB91eJ9v8rhIuTFt+8y+mennvxGj56tioGjE8NQjYcVETF F/h0DLBJvYVKeAXUChxFdpnr2d+T478v12kk56HkbZdc5L0hgT4UnAJkDlXaj4mQ == Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4e1ubdq34c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 11 May 2026 09:12:31 +0000 (GMT) Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 64B8sPXF016793; Mon, 11 May 2026 09:12:31 GMT Received: from smtprelay05.wdc07v.mail.ibm.com ([172.16.1.72]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 4e2f8q4pdg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 11 May 2026 09:12:31 +0000 (GMT) Received: from smtpav05.dal12v.mail.ibm.com (smtpav05.dal12v.mail.ibm.com [10.241.53.104]) by smtprelay05.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 64B9CUWC33620644 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 11 May 2026 09:12:30 GMT Received: from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E585958067; Mon, 11 May 2026 09:12:29 +0000 (GMT) Received: from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 65B0258065; Mon, 11 May 2026 09:12:27 +0000 (GMT) Received: from [9.123.6.34] (unknown [9.123.6.34]) by smtpav05.dal12v.mail.ibm.com (Postfix) with ESMTP; Mon, 11 May 2026 09:12:27 +0000 (GMT) Message-ID: <67f5b175-7a9e-4693-95ce-84d4b42e6b45@linux.ibm.com> Date: Mon, 11 May 2026 14:42:25 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/memory_hotplug: Factor out altmap freeing checks To: Muchun Song , David Hildenbrand , Oscar Salvador , Andrew Morton , linux-mm@kvack.org Cc: muchun.song@linux.dev, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260511084307.1827127-1-songmuchun@bytedance.com> Content-Language: en-US From: Donet Tom In-Reply-To: <20260511084307.1827127-1-songmuchun@bytedance.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=BezoFLt2 c=1 sm=1 tr=0 ts=6a019d7f cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=IkcTkHD0fZMA:10 a=NGcC8JguVDcA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VwQbUJbxAAAA:8 a=968KyxNXAAAA:8 a=VnNF1IyMAAAA:8 a=Uail7pCi9VyjTqRTir0A:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: fdcB4qRrTqLF4DtyW6B9LVSZHJfAxZTf X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTExMDEwMCBTYWx0ZWRfX2eRwCj+7uMQ5 v4MWT3UjCyTxnkpX5VQqYC2W6PoVj8rr4nO4raC+au2LCS/78p8LRvXsy4BK9Sdc8H/230Vpclh KAnCZ0CVm9NsfgE3+r/amdhaFDcyepqwKORgXidpkRIHcQiyDvoj8xvaXKDtdLAqz87/O/1n3pF Yq2HiZSPwcOtya14p4K1r/8qgWsKtHLbm+RpHUVJVPPHFYdHy98eVm0izUj1iIA89F+8sOFObPT lDRgAM09w4ZEc+/PrBRMk9EY3jrBn0tJk4jlzwtb+SZViMiRU6L3pG6AGXDbbTHYYNzqkWtFW88 fZyKrTAnBt8KBmM7E1JaflYz6e13NmJcceRviG6KAI3ZTE7JZQz+I76i/iTxztMARb5oCeWuspC tShFtx6ep4nFPs5m+6iO4X8hao4qLdYlPJzW+b6o6joqBgpMOqSw2CBcO4JmtLNdNFwmfYnNgnd YAqBu8qeBZ+H+LZ9fKw== X-Proofpoint-ORIG-GUID: fdcB4qRrTqLF4DtyW6B9LVSZHJfAxZTf X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-05-11_02,2026-05-08_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 priorityscore=1501 bulkscore=0 phishscore=0 malwarescore=0 adultscore=0 lowpriorityscore=0 suspectscore=0 impostorscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604200000 definitions=main-2605110100 On 5/11/26 2:13 PM, Muchun Song wrote: > Use a small helper to centralize altmap freeing after verifying that all > vmemmap pages were released. This keeps the check consistent between the > normal teardown path and the memory hotplug error paths. > > Suggested-by: David Hildenbrand (Arm) > Signed-off-by: Muchun Song looks good to me. Reviewed-by: Donet Tom -Donet > --- > mm/memory_hotplug.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 462d8dcd636d..af5489f03771 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1403,6 +1403,12 @@ bool mhp_supports_memmap_on_memory(void) > } > EXPORT_SYMBOL_GPL(mhp_supports_memmap_on_memory); > > +static void altmap_free(struct vmem_altmap *altmap) > +{ > + WARN_ONCE(altmap->alloc, "Altmap not fully unmapped"); > + kfree(altmap); > +} > + > static void remove_memory_blocks_and_altmaps(u64 start, u64 size) > { > unsigned long memblock_size = memory_block_size_bytes(); > @@ -1427,12 +1433,8 @@ static void remove_memory_blocks_and_altmaps(u64 start, u64 size) > put_device(&mem->dev); > > remove_memory_block_devices(cur_start, memblock_size); > - > arch_remove_memory(cur_start, memblock_size, altmap, NULL); > - > - /* Verify that all vmemmap pages have actually been freed. */ > - WARN(altmap->alloc, "Altmap not fully unmapped"); > - kfree(altmap); > + altmap_free(altmap); > } > } > > @@ -1463,7 +1465,7 @@ static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, > /* call arch's memory hotadd */ > ret = arch_add_memory(nid, cur_start, memblock_size, ¶ms); > if (ret < 0) { > - kfree(params.altmap); > + altmap_free(params.altmap); > goto out; > } > > @@ -1472,7 +1474,7 @@ static int create_altmaps_and_memory_blocks(int nid, struct memory_group *group, > params.altmap, group); > if (ret) { > arch_remove_memory(cur_start, memblock_size, params.altmap, NULL); > - kfree(params.altmap); > + altmap_free(params.altmap); > goto out; > } > } > > base-commit: e98d21c170b01ddef366f023bbfcf6b31509fa83