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 5B1472076B0 for ; Wed, 16 Oct 2024 12:01:37 +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=1729080097; cv=none; b=iR8rF/JKBEHqJFzWtrVaYa/cXcJrJpFKQE3NmsNXtsy6eMs49/jxRPmo0WcIDY+mgO8k1abAkbsxT5o+eJTuTHtXBL5eH22MVHBbTxvYhVa1nU39TgmDIMjNKWy68chZe05kAgB5yPVR2LNH2Kk8fwluEhbedmjXXB3pJMRiNDI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729080097; c=relaxed/simple; bh=0wvAIZuJtVKXK3ZNWEeGI+f35fphWLLFON9Xv00nJtk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CqmNjXi2/4OeYZ9EL1CI0xZ28GtBMfqq0ZVmRKaNp7p1XPuxOCK/59KfQyjk8lu283hXCUZgoTPvkkm/l/yySIaMd7gLTok+4BzLfSpKQBNap2fnU9E7Ha4nioEZrjlSvOsUVSbONlzad9Vx2sjM4Ea94wFBRT0qAluXaE79yZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YEZDFPs4; 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="YEZDFPs4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90725C4CEC5; Wed, 16 Oct 2024 12:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729080096; bh=0wvAIZuJtVKXK3ZNWEeGI+f35fphWLLFON9Xv00nJtk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YEZDFPs4oMQkuFmLAxFf9PGNhUSf+WbpaQp7U9Wu8VCYlBZy5+PXB9Ik9HsYa6peW jEbE+tfQw6WVBzH8VHTkWLuHdLYOFfTiSKxa5HAi7v79gvU/vPsxQN/OgRgQKVpVNl KmliJIIHPyVNBRaBhe1pWea5wFBQphkT2BZEEwlwy3dzvWu8GMiuW9AY0govJlA4t2 XuyZ7oTF+MVN+gsIOyNirYaZuAACHQ3Go4mRUZJi5MQp2jW2Pr36vWayqTf9zMRwY7 J1nM5HjwLkApUIi4+2g9EMI4VjEvf+TvJIm+Inri5Nn4Vk3mzoC+w3fWvDE2zSnBOY qAPC+mB9vkl9Q== Date: Wed, 16 Oct 2024 14:57:59 +0300 From: Mike Rapoport To: Su Hua 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: Hi, On Sat, Oct 12, 2024 at 11:55:31AM +0800, Su Hua wrote: > Hi Mike > > Thanks for your advice and sorry for taking so long to reply. Please don't top-post on the Linux kernel mailing lists > I looked at the logic again. deferred_init_pages is currently used to > handle all (memory &&! reserved) area memblock，and put that memory in > buddy. > Change it to also handle reserved memory may involve more code > changes. I wonder if I can change the commit message: This patch is > mainly to > make the migration type to MIGRATE_MOVABLE when the reserve type page > is initialized, regardless of whether CONFIG_DEFERRED_STRUCT_PAGE_INIT > is set or not? > > When not set CONFIG_DEFERRED_STRUCT_PAGE_INIT， initializes memblock of > reserve type to MIGRATE_MOVABLE by default at memmap_init initializes > memory. This should be more clearly emphasized in the commit message. > Sincerely yours， > Su > > > Mike Rapoport 于2024年9月29日周日 17:18写道： > > > > 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(); No need to call cond_resched() here > > > + } > > > + > > > __init_single_page(pfn_to_page(pfn), pfn, zid, nid); > > > } > > > #else > > > -- > > > 2.34.1 > > > > > > > -- > > Sincerely yours, > > Mike. -- Sincerely yours, Mike.