From: Oscar Salvador <osalvador@suse.de>
To: Muchun Song <songmuchun@bytedance.com>
Cc: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
peterz@infradead.org, viro@zeniv.linux.org.uk,
akpm@linux-foundation.org, paulmck@kernel.org,
mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com,
rdunlap@infradead.org, oneukum@suse.com,
anshuman.khandual@arm.com, jroedel@suse.de,
almasrymina@google.com, rientjes@google.com, willy@infradead.org,
mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com,
naoya.horiguchi@nec.com, duanxiongchun@bytedance.com,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v10 00/11] Free some vmemmap pages of HugeTLB page
Date: Thu, 17 Dec 2020 15:59:58 +0100 [thread overview]
Message-ID: <20201217145953.GA13874@linux> (raw)
In-Reply-To: <20201217121303.13386-1-songmuchun@bytedance.com>
On Thu, Dec 17, 2020 at 08:12:52PM +0800, Muchun Song wrote:
> In this case, for the 1GB HugeTLB page, we can save 4088 pages(There are
> 4096 pages for struct page structs, we reserve 2 pages for vmemmap and 8
> pages for page tables. So we can save 4088 pages). This is a very substantial
> gain. On our server, run some SPDK/QEMU applications which will use 1024GB
> hugetlbpage. With this feature enabled, we can save ~16GB(1G hugepage)/~11GB
> (2MB hugepage, the worst case is 10GB while the best is 12GB) memory.
Is the above really true?
We no longer need to allocate pagetables, so the savings go up to 4094, right?
I will be off for a few days but I expect to get back to this and review the
missing bits when I am back.
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2020-12-17 15:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-17 12:12 [PATCH v10 00/11] Free some vmemmap pages of HugeTLB page Muchun Song
2020-12-17 12:12 ` [PATCH v10 01/11] mm/memory_hotplug: Factor out bootmem core functions to bootmem_info.c Muchun Song
2020-12-17 12:12 ` [PATCH v10 02/11] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Muchun Song
2020-12-18 15:41 ` Oscar Salvador
2020-12-21 23:56 ` Mike Kravetz
2020-12-17 12:12 ` [PATCH v10 03/11] mm/hugetlb: Free the vmemmap pages associated with each HugeTLB page Muchun Song
2020-12-21 9:11 ` Oscar Salvador
2020-12-21 11:25 ` [External] " Muchun Song
2020-12-21 13:43 ` Oscar Salvador
2020-12-21 15:52 ` Muchun Song
2020-12-21 18:00 ` Oscar Salvador
2020-12-22 1:03 ` Mike Kravetz
2020-12-22 2:49 ` Muchun Song
2020-12-17 12:12 ` [PATCH v10 04/11] mm/hugetlb: Defer freeing of HugeTLB pages Muchun Song
2020-12-21 10:27 ` Oscar Salvador
2020-12-21 11:07 ` [External] " Muchun Song
2020-12-21 14:14 ` Oscar Salvador
2020-12-21 15:18 ` Muchun Song
2020-12-17 12:12 ` [PATCH v10 05/11] mm/hugetlb: Allocate the vmemmap pages associated with each HugeTLB page Muchun Song
2020-12-17 12:12 ` [PATCH v10 06/11] mm/hugetlb: Set the PageHWPoison to the raw error page Muchun Song
2020-12-17 12:12 ` [PATCH v10 07/11] mm/hugetlb: Flush work when dissolving hugetlb page Muchun Song
2020-12-21 10:40 ` Oscar Salvador
2020-12-21 11:07 ` [External] " Muchun Song
2020-12-17 12:13 ` [PATCH v10 08/11] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Muchun Song
2020-12-17 12:13 ` [PATCH v10 09/11] mm/hugetlb: Introduce nr_free_vmemmap_pages in the struct hstate Muchun Song
2020-12-21 8:16 ` Oscar Salvador
2020-12-21 9:33 ` [External] " Muchun Song
2020-12-17 12:13 ` [PATCH v10 10/11] mm/hugetlb: Gather discrete indexes of tail page Muchun Song
2020-12-18 9:06 ` Oscar Salvador
2020-12-18 9:41 ` [External] " Muchun Song
2020-12-17 12:13 ` [PATCH v10 11/11] mm/hugetlb: Optimize the code with the help of the compiler Muchun Song
2020-12-17 12:17 ` [PATCH v10 00/11] Free some vmemmap pages of HugeTLB page David Hildenbrand
2020-12-17 14:59 ` Oscar Salvador [this message]
2020-12-17 15:52 ` [External] " Muchun Song
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