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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 20C61CD98CF for ; Mon, 15 Jun 2026 19:40:10 +0000 (UTC) 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-Owner; bh=h7B8DczUlZvoXStP+g9L9ex1t6hea3WLt+N+VMfAkwQ=; b=cO0VRrp0E6J3bVxJfZANM5kSFT 6mA/zsCktPiTbP3Ka/mmWb6peLhYQJpyMsvrYgEQfFPTrGS+2z5n4vFxAeJ//sMLdOayE7oDOsmq1 LOA15sudIS5BjEOGBDFmmg491nS0RBgv9/Mni2HnAEm1Sx3FUT1PFuLIIxhAectFl96dgs2Ma3i5u I74DQWEc8Px6bqunTRuwfqpwSDuD6lNR7PWn7McF+j+A6nSmWgIVPNTMq7yhiBx0Gt4qaz4X0zGBc cZUUMWJVtf4X/1CUotHGfg79MfAgt0HLY8ub/vlPAvvTyA81boMNfTNFnRSoVYI5eXFS438gWFHXU 52gp4ysA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wZDAH-0000000EmmI-2YLm; Mon, 15 Jun 2026 19:40:09 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wZDAG-0000000EmmA-2B6y for kexec@lists.infradead.org; Mon, 15 Jun 2026 19:40:08 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id D37FA40AAA; Mon, 15 Jun 2026 19:40:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01C251F000E9; Mon, 15 Jun 2026 19:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781552407; bh=h7B8DczUlZvoXStP+g9L9ex1t6hea3WLt+N+VMfAkwQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=WKQue0AH0htjX4UnzX+Hx1GmH8vKLOTbqpeJ7AM4DBR/0gN8Lz3FXAQtOwe0fysZY +6C81/uwDS4zGXp7VX5qIkE8+MraetDUvRtVpm5Wz3LiSS7TXWi6GH3fhFrNlFI5UN 4I7339GVUqdaNYa/SMZ9Hg1K+aB8gXDwIgPG4AYl/1GS2xwkXnmDLC9ZSbkWTMWLvb snXbil0WlO5o6bCGeqAkOAMKayAT+77FzegUGxIekv+Ho6iASyP9CXNnnrS1bdiV+/ 7Pb2XnLtIB1fo3koDUQ9pd+XgQwqi5VnPipybsMlwvUov2Y5uBd7mppz9OI/Y2ZgIz pEC8BIWKh32bw== Date: Mon, 15 Jun 2026 22:40:00 +0300 From: Mike Rapoport To: Pratyush Yadav Cc: Pasha Tatashin , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu , Jork Loeser , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 16/18] memblock: make HugeTLB bootmem allocation work with KHO Message-ID: References: <20260605183501.3884950-1-pratyush@kernel.org> <20260605183501.3884950-17-pratyush@kernel.org> <178143855120.2123877.5431342391381982046.b4-review@b4> <2vxzpl1soris.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2vxzpl1soris.fsf@kernel.org> X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Mon, Jun 15, 2026 at 03:35:39PM +0200, Pratyush Yadav wrote: > On Sun, Jun 14 2026, Mike Rapoport wrote: > > On Fri, 05 Jun 2026 20:34:49 +0200, Pratyush Yadav wrote: > > > >> First, it does not use mirrored memory for hugetlb. Mirrored memory is a > >> limited resource that is best saved for kernel data structures, not user > >> memory. > >> > >> Second, if the memory found overlaps with KHO scratch areas, it discards > >> the memory and retries. > > > > This sentence is somewhat hard to parse. > > Okay, let me retry: > > Second, if the free memory area found by memblock_find_in_range_node() > is a part of a KHO scratch area, the free area is not used. Allocation > is retried starting after the free area to ensure no hugepages come from > KHO scratch. > > Any better? Yep :) > > > >> > >> > >> diff --git a/mm/memblock.c b/mm/memblock.c > >> index 6349c48154f4..131e54dd5d8d 100644 > >> --- a/mm/memblock.c > >> +++ b/mm/memblock.c > >> @@ -1756,6 +1761,69 @@ void * __init memblock_alloc_try_nid_raw( > >> [ ... skip 51 lines ... ] > >> + if (memblock_bottom_up()) > >> + start = addr + size; > >> + else > >> + start = addr - size; > >> + > >> + goto retry; > > > > Hmm, two goto retry don't seem nice :/ > > Although I can't see how to imporove it really. > > Dunno, looked easy enough to understand to me. > > > > Maybe add a helper for going the node fallback? > > There is a small downside. There will then be no way to know the > fallback was tried already, so if a retry is done because of scratch > overlap, the fallback needs to be done again. > > I don't think it should be too bad, so if you still prefer this then I > can do it. Let's keep it for now, maybe will find something smarter later. > -- > Regards, > Pratyush Yadav -- Sincerely yours, Mike.