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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1923BC5AC82 for ; Mon, 10 Aug 2026 03:16:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC5E86B008C; Sun, 9 Aug 2026 23:16:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D763C6B0092; Sun, 9 Aug 2026 23:16:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8D896B0093; Sun, 9 Aug 2026 23:16:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 98BDB6B008C for ; Sun, 9 Aug 2026 23:16:43 -0400 (EDT) Received: from smtpin01.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 89F8B1404CD for ; Mon, 10 Aug 2026 03:16:41 +0000 (UTC) X-FDA: 85083897402.01.59D8C31 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by imf07.hostedemail.com (Postfix) with ESMTP id DB6DB40004 for ; Mon, 10 Aug 2026 03:16:39 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=surriel.com header.s=mail header.b=aoI+iny3; spf=pass (imf07.hostedemail.com: domain of riel@surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@surriel.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786331800; h=from:from:sender: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:dkim-signature; bh=DPDbH0uDy9khnXmwsHeDwlaELQ6SwGd2GWPEwSHHQbI=; b=jf1Hf9O/mH/CJIsLp/CKGflSvjTrwrDoE56azvbas9xxr/I3PivurQXfG9e8InSYvgj/fP ovk56LY83XSauHUTUQPD+miMK90xvmwjR+kDT9L6OukoFiezSdRF6bj/BptVOP7IbS3sex P0pQUb+WJ/bRQxUSs5jqn64SN6tJLWM= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786331800; b=oPLnsCxZ0CENhHnbjzGmwdStuqUC9i/tD1BJZPet9QmRm8OGsdhytWKS5xL6HRFTc+ugau xbtuJ03ET4+Z7KhQ/UFy81VrU0t5GPJuX80EUPaQgkcyq+PqmNglLVzuULJiHhWpXVq/Q6 kOVifSuIx8+mZBBUptgoSCaOrMU84Tw= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=surriel.com header.s=mail header.b=aoI+iny3; spf=pass (imf07.hostedemail.com: domain of riel@surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@surriel.com; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=MIME-Version:Content-Transfer-Encoding:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=DPDbH0uDy9khnXmwsHeDwlaELQ6SwGd2GWPEwSHHQbI=; b=aoI+iny3FaGb3bAaDsa0/UBRlL O+VeMxmEN3Y7AStBqsGmtlZufMKqDGHw1GDrO+5YH78pdQTtig+r+YyoejMiAWy7hvOVH1GDOOHTZ r8dI/ON94AHdZ4wXn8r7ThiGGajXB1aFKLG9C1kIcLQmIHW46tSx09L198TGJ4vvUfTwbOUXH5C7H 9DZqZTat5WE+QjFhSRd811f47Y1n8lYUtwkVQxd7qGKH5gRJ1Iobfnvty7XbjPAMKycTUikFngCTl qNRfVaGaPlFjESwxpsUgqftbLTMrHYLdRTMI+WnwuHRAOiHtoMEVScLG7N4setaYuGr+Hl1n8PvSR Hu46WO2g==; Received: from [96.67.55.146] by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1wtGUx-000000002vh-25s0; Sun, 09 Aug 2026 23:16:23 -0400 Message-ID: <705e54c4cd6f49c930208e450cdf488e8e75cc21.camel@surriel.com> Subject: Re: [RFC PATCH] mm/cma: don't release CMA pages still in use From: Rik van Riel To: Andrew Morton Cc: David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Date: Sun, 09 Aug 2026 23:16:23 -0400 In-Reply-To: <20260809210608.06b5ccb9@fangorn> References: <20260809210608.06b5ccb9@fangorn> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) MIME-Version: 1.0 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: DB6DB40004 X-Stat-Signature: 77s7wo5mb46cm1pnns1xfg97ztrd4yi8 X-Rspam-User: X-HE-Tag: 1786331799-940278 X-HE-Meta: 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 h11RkZln tOPLjkOj2tOJ8LarsHi133MSK5AGrHxHHgTswtNBLf65Qk2EEISlNFS1+IrfcezYPEwD+OUX3qNwv6hFBujpsR7TNCf+2tBDaB6cXEuEHGdA/0dG7aLlW+5JfAUpxixi2KT9WfcnR/8D+OzoHqwAPAOpXsU/q/U+S6XobQYH0wIWu5j7+B6hw/7Z/+NJvF6pq8PBkH4fsuIvB3hC/gj6/d7nr/zLVK1c2iE8e1MiyAb/HeoucDI6GAVLJjp1IXn/gRzoJjZxmkGkAss8L/eE/Y/zu6g== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, 2026-08-09 at 21:06 -0400, Rik van Riel wrote: >=20 > This change should be safe because nothing can get reallocated while > it > is still in use. And of course Sashiko found something I overlooked. I'll spin a v2 tomorrow. https://sashiko.dev/#/patchset/20260809210608.06b5ccb9@fangorn The hugetlb CMA code uses order 9 as the smallest size that may be returned to the CMA allocator, which I suppose works because when mTHPs, THPs, and other movable large folios end up in the hugetlb CMA area, those do not go through the CMA allocator, and never touch the bitmap? That additional bitmap alongside of the pages and page blocks looks like trouble.