From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04D98606B417 for ; Wed, 11 Nov 2026 11:09:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=m0pN5gfc; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.a=rsa-sha256 header.s=smtpauto.stravinsky header.b=cmaAuP8N DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=1E8ZwW2Eu8WYRG4t6PuIDQjLMNRBTfUw3ilSDjs1rRU=; b=m0pN5gfcWPBgCGSNFbMzwVM1ZS dGSkG8wRsOYtJqp8sFcTJh74prjyktySVINI5MWdFVcs9BXU6McjLm5yWqMerA+Yz+kK4y0HV6289 vlVLTjDUhLMdxJHhkfjgRi4svkDvMRZBTiGokwqcGrIbBe4pTZWX2cgCeipMZc9ElIQf4hC1MZX6t MsCRdV/3NJ6VyYFpw5iwT/0nQgYMFxhjJzVwLnqKpqygVARf2k6xQU3w/Wh2YYmEq7AZkxVsVy99b jF66K8XFqGz5o2ZvVaxoAyg97yVarq0YgGAeB3HXn9ZwBkRxA06WXFIlVLGcKGngprbLUJYLB2IOx EdMfAkeA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xR6CU-00000006RNC-2UnL; Wed, 11 Nov 2026 11:09:10 +0000 Received: from stravinsky.debian.org ([2001:41b8:202:deb::311:108]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xR6CN-00000006RGW-49l4 for kexec@lists.infradead.org; Wed, 11 Nov 2026 11:09:07 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1E8ZwW2Eu8WYRG4t6PuIDQjLMNRBTfUw3ilSDjs1rRU=; b=cmaAuP8N+P52iDtJVOwMGPU1Rm FqzHy98fPelH0mq8DY0owqaAxg/oEFesnLx84zScoPFheV2k7WVlrIMZiD+YqhJOtdi1Uad5BMK9F 6en5BPWw+v3fE+/rL0Y5CGl2nlw31TWn7YIv55D9SZjD1cX3jcE0XFY9dru8/P/fJ9kxPBYu19j9r dQCRq3bb5gxvXhKwVOCKpAVuCo/ZyutzCT/zkQXD2VE5qDpt5OROuRuNhBFVcpEfNi5ysabYpZyI6 NrlmK+fONZ1CyH6Ge32APS7qP0t5pyBN5b2pWN8ZWGxHWvL80WG44ipLS8WqhJtviyLV0r98zCRA3 +B8IoyiQ==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1xR6CD-00D8c2-2m; Wed, 11 Nov 2026 11:08:54 +0000 Date: Wed, 11 Nov 2026 03:08:48 -0800 From: Breno Leitao To: Chris Down Cc: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Alexander Graf , Baoquan He , Jonathan Corbet , Shuah Khan , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH 1/9] kho: Reclaim the metadata page left reserved after kexec Message-ID: References: <63ca64c004b296a998a3e531f8c0c4964916b70c.1794383544.git.chris@chrisdown.name> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <63ca64c004b296a998a3e531f8c0c4964916b70c.1794383544.git.chris@chrisdown.name> X-Debian-User: leitao X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261111_030904_054819_4D725E53 X-CRM114-Status: UNSURE ( 7.69 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -4.4 (----) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Nov 10, 2026 at 11:52:55PM -0800, Chris Down wrote: > After a KHO kexec, the new kernel keeps the page holding the previous > kernel's kexec metadata reserved for as long as it runs. It only needs > the page once, since kho_in_kexec_metadata() copies the previous release > and the kexec count out of it at boot, and nothing reads it again. Good catch. > > Free it with kho_restore_free() once copying is complete. > > Fixes: 76aa46b9e404 ("kho: kexec-metadata: track previous kernel chain") > Signed-off-by: Chris Down Tested-by: Breno Leitao