From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 37FA94457B1 for ; Fri, 31 Jul 2026 15:55:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785513325; cv=none; b=KqRzEb8u3cqDI3SsVLDE7VbQOIntezmw1J6BKadXtNGHl7+LKWnAmsryR2+fq0ITEX6/rXLxwhSCb/ZNNEkRIgm/0WKJhuOb94oS69DRc5O1uLumfTc0GUZ1FGuYy+GbWIg3bZHCKEoaWpX+tIkkrTELcb4n9YiamOHPxrnzmZw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785513325; c=relaxed/simple; bh=rV8nBJFnfG2GCaRpLts+gSbWqrdQBPDmfooT330Oc+A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M4BXb+i/MmCl26FPXTb3U9ajWF1TThTIwMkexumgkxda8zS09rVeb+42TEUcMXmk0a2x4J9nR1fFAqWo0bJIQjFKYw3QTxXLpDzwck+vQV80H9MfqcME1mUBcgoyZyMe1mluomcJbD/9kQ+VKUoFzeH1Zbgtn2LC6qZwNNZ/BZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aQrz+q+j; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aQrz+q+j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2740C1F00AC4; Fri, 31 Jul 2026 15:55:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785513323; bh=rV8nBJFnfG2GCaRpLts+gSbWqrdQBPDmfooT330Oc+A=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=aQrz+q+jmtWscHrp9E+JMtT7juGxIgBJ3k9QargV1FyQBz2ttEjM99JD/jGxdWEGw /c5KRx/P0sBey4T/Qy/3YB6loaZcpj+tPfwVDTGjIue0RhaFOU1Gp7IAYSxDt8vntP MJnrnfKJHRSm2RQeLZcuO47Ak1d92ouTrk6J+jywUfIPCc8mLnKQgHG5tsD+pOUh13 b0prcn+AFcDCYUGCq+lzyhJLdEBoO9LLM2D+Ib6/Sfncw8dJA8BdUY+Fq7gDh+LoJO mF4ExPOvMNBpc/WnbTG583ancA4tYXxxFUDSZwNsxBiMmBsvCLKRmT+Gt0ylRSi04/ IoTfI8rPInNoA== Date: Fri, 31 Jul 2026 16:55:05 +0100 From: "Lorenzo Stoakes (ARM)" To: Juan Yescas Cc: "David Hildenbrand (Arm)" , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , open list , "open list:MEMORY MANAGEMENT - CORE" , android-mm@google.com, fvdl@google.com, tkjos@google.com, minchan@google.com, dskiba@google.com Subject: Re: [RFC PATCH 00/16] Page Alloc Hogger Message-ID: References: <20260723074854.1013941-1-jyescas@google.com> <97605949-82c5-49e0-84b6-b42e8078b55d@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 31, 2026 at 08:32:35AM -0700, Juan Yescas wrote: > On Thu, Jul 30, 2026 at 12:51 AM Lorenzo Stoakes (ARM) wrote: > > > > On Tue, Jul 28, 2026 at 05:36:03PM -0700, Juan Yescas wrote: > > > On Tue, Jul 28, 2026 at 12:29 PM David Hildenbrand (Arm) > > > wrote: > > > > > > > > On 7/23/26 09:47, Juan Yescas wrote: > > > > > This patch series introduces the Page Alloc Hogger. The Page Alloc Hogger > > > > > allows you to allocate memory pages from specific nodes, zones, migration > > > > > types, and orders directly via debugfs. This provides key benefits for > > > > > testing and debugging: > > > > > > > > Would it be feasible to carry this as an OOT debugging module? Would a lot of > > > > symbols be missing to achieve that? > > > > > > > > > > Thanks David for the comment. > > > > > > The only symbol that would be needed to have this module as OOT is > > > "migratetype_names". > > > > I mean you could hardcode these and be pretty safe :) I don't we're going > > to add any time soon and if we did you'd probably need to change the module > > code anyway? > > Thanks Lorenzo, I agree, the names can be hardcoded. Yeah :) I think not such an issue. > > > I feel this debug module should be a noop in core. > > What would be the main concern here? > > The reason I wrote this module is because my team and system teams who > work in memory, > have programs to alloc/free memory to debug memory issues. These > programs are not shared and > depending on the memory issue, developers customize their programs. If we want > to allocate memory that is not MOVABLE, we need to write custom kernel > drivers for that. This code > is reinvented constantly by developers. Exposing internal implementation details via debugfs is problematic as a core feature. It's not impossible for this to be upstream however as a separate driver on the basis of people re-inventing? > > With this self contained module, we can allocate any valid memory from > any node/zone/order/migrate type > without needing custom programs or drivers. > > Greetings > Juan > > > Cheers, Lorenzo -- Cheers, Lorenzo