From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rYTRV26ByzDqDR for ; Tue, 21 Jun 2016 10:40:54 +1000 (AEST) In-Reply-To: <1462958539-25552-1-git-send-email-oohall@gmail.com> To: Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Cc: linux-mm@kvack.org, Oliver O'Halloran Subject: Re: [v2] powerpc/mm: Ensure "special" zones are empty Message-Id: <3rYTRT6gDSz9t0f@ozlabs.org> Date: Tue, 21 Jun 2016 10:40:53 +1000 (AEST) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2016-11-05 at 09:22:18 UTC, Oliver O'Halloran wrote: > The mm zone mechanism was traditionally used by arch specific code to > partition memory into allocation zones. However there are several zones > that are managed by the mm subsystem rather than the architecture. Most > architectures set the max PFN of these special zones to zero, however on > powerpc we set them to ~0ul. This, in conjunction with a bug in > free_area_init_nodes() results in all of system memory being placed in > ZONE_DEVICE when enabled. Device memory cannot be used for regular kernel > memory allocations so this will cause a kernel panic at boot. Given the > planned addition of more mm managed zones (ZONE_CMA) we should aim to be > consistent with every other architecture and set the max PFN for these > zones to zero. > > Signed-off-by: Oliver O'Halloran > Reviewed-by: Balbir Singh > Cc: linux-mm@kvack.org Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/3079abe555511031e2ba5d1e21 cheers