From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 89AE722092 for ; Sun, 29 Sep 2024 09:18:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727601497; cv=none; b=V7aDdhrRWF+b9stNxpGG34uEs9U1fXCgFxPDTDUqy0batoPl86+c2NLw4TPEUv6KCLzXJVMFlXG3Hb/XjViEOXcxAdbBr3zLHzqb36B4Q55rBLcwPdVpSJas4TitBlHDvfc3jM+54AHJStnAdU62njvDRgMhmGwDanPaD4YF/fQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727601497; c=relaxed/simple; bh=vrFJDvLvXruD2pfE+p9bt0gIo4ESSyyo7ec0Oqtc7eI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e329fWaLONRlSpHXCrxqSsncD58uJ/f2htVPTkFI2ua1lF501CJY0kIcV7WN5MNvWqIjwlVCbSACqU/qYKqfkq6xSCq65cNNmedPQkJ0bCVopTpetn54tlJZu8DhCsf3rXO4XybxhJHlvC2hs5JGOTsfShUcylYzqp9DD2b2RDs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pL7Ypfqy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pL7Ypfqy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE664C4CEC5; Sun, 29 Sep 2024 09:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727601497; bh=vrFJDvLvXruD2pfE+p9bt0gIo4ESSyyo7ec0Oqtc7eI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pL7Ypfqy3y+BEQPyxLVxRR0kKhETeRJNEvrLbNWaPQ/Gc1Gl1qbpBDN4CBpjecWB3 I0jSEHf/oUPnYMzqXeLAxuKcwcQmFJIRu5auGHt58OQhqMmQPCHyj9+fChmoo5KTl/ jDEMGdaYg5rdyNppWRGIf8FWan7+BvY6cfcrALgaEhpVTHDMi8g7TB5FEpdUaGUSMm FJl0pyIg3tagTXnKdGZ3HRQa9cVDviED67ROtwD13gSRgxsdtCmjmCjHydrbWUbEuY iUcFkdWI8obmBxUhOm5J8m3dQf7F3o5Of0H3PkwfIBnJwSlrDel3a7/DRVdiBlPezj QQfr/qWmyS7qw== Date: Sun, 29 Sep 2024 12:15:02 +0300 From: Mike Rapoport To: suhua Cc: akpm@linux-foundation.org, muchun.song@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, suhua Subject: Re: [PATCH v1] memblock: Initialized the memory of memblock.reserve to the MIGRATE_MOVABL Message-ID: References: <20240925110235.3157-1-suhua1@kingsoft.com> 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: <20240925110235.3157-1-suhua1@kingsoft.com> On Wed, Sep 25, 2024 at 07:02:35PM +0800, suhua wrote: > After sparse_init function requests memory for struct page in memblock and > adds it to memblock.reserved, this memory area is present in both > memblock.memory and memblock.reserved. > > When CONFIG_DEFERRED_STRUCT_PAGE_INIT is not set. The memmap_init function > is called during the initialization of the free area of the zone, this > function calls for_each_mem_pfn_range to initialize all memblock.memory, > excluding memory that is also placed in memblock.reserved, such as the > struct page metadata that describes the page, 1TB memory is about 16GB, > and generally this part of reserved memory occupies more than 90% of the > total reserved memory of the system. So all memory in memblock.memory is > set to MIGRATE_MOVABLE according to the alignment of pageblock_nr_pages. > For example, if hugetlb_optimize_vmemmap=1, huge pages are allocated, the > freed pages are placed on buddy's MIGRATE_MOVABL list for use. Please make sure you spell MIGRATE_MOVABLE and MIGRATE_UNMOVABLE correctly. > When CONFIG_DEFERRED_STRUCT_PAGE_INIT=y, only the first_deferred_pfn range > is initialized in memmap_init. The subsequent free_low_memory_core_early > initializes all memblock.reserved memory but not MIGRATE_MOVABL. All > memblock.memory is set to MIGRATE_MOVABL when it is placed in buddy via > free_low_memory_core_early and deferred_init_memmap. As a result, when > hugetlb_optimize_vmemmap=1 and huge pages are allocated, the freed pages > will be placed on buddy's MIGRATE_UNMOVABL list (For example, on machines > with 1TB of memory, alloc 2MB huge page size of 1000GB frees up about 15GB > to MIGRATE_UNMOVABL). Since the huge page alloc requires a MIGRATE_MOVABL > page, a fallback is performed to alloc memory from MIGRATE_UNMOVABL for > MIGRATE_MOVABL. > > Large amount of UNMOVABL memory is not conducive to defragmentation, so > the reserved memory is also set to MIGRATE_MOVABLE in the > free_low_memory_core_early phase following the alignment of > pageblock_nr_pages. > > Eg： > echo 500000 > /proc/sys/vm/nr_hugepages > cat /proc/pagetypeinfo > > before： > Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 > … > Node 0, zone Normal, type Unmovable 51 2 1 28 53 35 35 43 40 69 3852 > Node 0, zone Normal, type Movable 6485 4610 666 202 200 185 208 87 54 2 240 > Node 0, zone Normal, type Reclaimable 2 2 1 23 13 1 2 1 0 1 0 > Node 0, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0 > Node 0, zone Normal, type Isolate 0 0 0 0 0 0 0 0 0 0 0 > Unmovable ≈ 15GB > > after： > Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 > … > Node 0, zone Normal, type Unmovable 0 1 1 0 0 0 0 1 1 1 0 > Node 0, zone Normal, type Movable 1563 4107 1119 189 256 368 286 132 109 4 3841 > Node 0, zone Normal, type Reclaimable 2 2 1 23 13 1 2 1 0 1 0 > Node 0, zone Normal, type HighAtomic 0 0 0 0 0 0 0 0 0 0 0 > Node 0, zone Normal, type Isolate 0 0 0 0 0 0 0 0 0 0 0 > > Signed-off-by: suhua > --- > mm/mm_init.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 4ba5607aaf19..e0190e3f8f26 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -722,6 +722,12 @@ static void __meminit init_reserved_page(unsigned long pfn, int nid) > if (zone_spans_pfn(zone, pfn)) > break; > } > + > + if (pageblock_aligned(pfn)) { > + set_pageblock_migratetype(pfn_to_page(pfn), MIGRATE_MOVABLE); > + cond_resched(); > + } If you are trying to make initialization of pageblock migrate type consistent with or without CONFIG_DEFERRED_STRUCT_PAGE_INIT, move setting of migrate type from deferred_free_pages() to deferred_init_pages(). > + > __init_single_page(pfn_to_page(pfn), pfn, zid, nid); > } > #else > -- > 2.34.1 > -- Sincerely yours, Mike.