From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793921987; b=P5qBY7ssbvol0Xmq1yOA1+kwJgveFDNi0ga97COzdTyLqHliltva4XJsQ2ZUlMjFny0m 0DzvfOBtpEUMzgpVBlYmiNMMv/grGfMZVsjP/yBXqmBMIY7zIz132eDMavWXrLtGmvpO1 mSMKyQSse2SLhLxuQFsfR4Fr6v/TY5jgOvYccsLCIwP05t+6ZWbHpxizmFTLeZtmrkGV1 JM/oZPbXybMjDJ+GfwEE37aa9WsW/uxfyhozSlyi0Xe2Cy8eFGwX0wvqnqerjBg1ppBSE gDFF85QAFHbVAuQ5XBk1fo8x7ZSiKUhJKFMTFaGibd9VR8ztDAF3bHQktOKriMQcTbw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793921987; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-Id: In-Reply-To:References:X-Mailer:Mime-Version:Content-Type: Content-Transfer-Encoding; bh=rCoKdv5eyx8+bEKQ/D7gBxIEUDff2HqusNXsd9z3Zfw=; b=Uvc0m1P9LcbcPwYLu4HMw6yLgjzoJvLIVDI3vkobBy5Nif+aRNbwnIHwqz+cJfhCfjCz kYc/5x6auKvXMAtAXOHTqgU4jYd+QBqtwrDEFxj7eTapkOw/QDKOqg7a4/ngYlqBNnc9w pcXRHCK7CyPiucG3bS2a81Vu2WzTUSA8GR6x+xd3gVX6vM1E3js8TyQ1vmW+TVv7LEZx5 4o5VcLjeMFgaPauUrmImM/usrWqaUSYBgDyV4ogwFaWKRDc70A7XCPay0ZuZsnOuRtEIw QTDDXaFQXcMwfbayIHe0lnF9s8Is3pTWv/GGQJ2Fdi27Ph+pjM4cLDniJuQgmMUh25A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b="bl0/J+OI"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A274606A326 for ; Thu, 5 Nov 2026 23:39:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=bl0/J+OI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F8051F0089F; Thu, 5 Nov 2026 23:39:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1793921986; bh=rCoKdv5eyx8+bEKQ/D7gBxIEUDff2HqusNXsd9z3Zfw=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=bl0/J+OI4ezSk/4AHOsUzY1DM5c6/1998yEWg2PnGHys9rxGEnN38LLVedu7ca1zc m6OFdKe/0gVYUJRUyjaUR2owSy8o7wVgnLtbtYUhrjTy7HpXtGg8GchEbNxi3iGtZW Tcf6rC/GUxnX3T5NkJK/ivmLT4CxHW/7tVxqBL7g= Date: Thu, 5 Nov 2026 15:39:45 -0800 From: Andrew Morton To: Mark Bundschuh Cc: , , , , , Subject: Re: [PATCH v2] mm/hugetlb: add htlb_dissolve vmstat event Message-Id: <20261105153945.e4a6415d8d0e8742887e9a86@linux-foundation.org> In-Reply-To: <20261105191508.1021974-1-mkbund@amazon.com> References: <20261105191508.1021974-1-mkbund@amazon.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 5 Nov 2026 19:15:08 +0000 Mark Bundschuh wrote: > Memory offline and memory failure handling dissolve free hugetlb folios > and lower nr_hugepages. Nothing records this, so when the pool shrinks > it is hard to tell whether that or a write to nr_hugepages caused it. Can we please have a much more detailed explanation of the motivation for this? I assume it's for the benefit of ops people, but why do they want this and how will it be used, etc? y'know, that old use-case thing. > Add an htlb_dissolve event, counted for each free folio that > dissolve_free_hugetlb_folio() takes out of the pool. I'm wondering why it doesn't account offline and memory-failure separately but without the above info I'm at a loss! Thanks.