From: Oscar Salvador <osalvador@suse.de>
To: Muchun Song <songmuchun@bytedance.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
Mike Kravetz <mike.kravetz@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
Peter Zijlstra <peterz@infradead.org>,
viro@zeniv.linux.org.uk,
Andrew Morton <akpm@linux-foundation.org>,
paulmck@kernel.org, mchehab+huawei@kernel.org,
pawan.kumar.gupta@linux.intel.com,
Randy Dunlap <rdunlap@infradead.org>,
oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de,
Mina Almasry <almasrymina@google.com>,
David Rientjes <rientjes@google.com>,
Matthew Wilcox <willy@infradead.org>,
Michal Hocko <mhocko@suse.com>,
"Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>,
David Hildenbrand <david@redhat.com>,
naoya.horiguchi@nec.com,
Xiongchun duan <duanxiongchun@bytedance.com>,
linux-doc@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [External] Re: [PATCH v10 03/11] mm/hugetlb: Free the vmemmap pages associated with each HugeTLB page
Date: Mon, 21 Dec 2020 19:00:19 +0100 [thread overview]
Message-ID: <20201221180019.GA2884@localhost.localdomain> (raw)
In-Reply-To: <CAMZfGtVTqYXOvTHSay-6WS+gtDSCtcN5ksnkj8hJgrUs_XWoWQ@mail.gmail.com>
On Mon, Dec 21, 2020 at 11:52:30PM +0800, Muchun Song wrote:
> On Mon, Dec 21, 2020 at 9:44 PM Oscar Salvador <osalvador@suse.de> wrote:
> >
> > On Mon, Dec 21, 2020 at 07:25:15PM +0800, Muchun Song wrote:
> >
> > > Should we add a BUG_ON in vmemmap_remap_free() for now?
> > >
> > > BUG_ON(reuse != start + PAGE_SIZE);
> >
> > I do not think we have to, plus we would be BUG_ing for some specific use
> > case in "generic" function.
>
> The vmemmap_remap_range() walks page table range [start, end),
> if reuse is equal to (start + PAGE_SIZE), the range can adjust to
> [start - PAGE_SIZE, end). But if not, we need some work to
> implement the "generic" function.
>
> - adjust range to [min(start, reuse), end) and call
> vmemmap_remap_rangeand which skip the hole
> which is [reuse + PAGE_SIZE, start) or [end, reuse).
> - call vmemmap_remap_range(reuse, reuse + PAGE_SIZE)
> to get the reuse page.Then, call vmemmap_remap_range(start, end)
> again to remap.
>
> Which one do you prefer?
I would not overcomplicate things at this stage.
Just follow my sugestion and add a BUG_ON as you said, that might be the
easier way now.
We can overthink this in the future when some other usecases come
around, right?
Thanks
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2020-12-21 18:01 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 [this message]
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
2020-12-17 15:52 ` [External] " Muchun Song
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201221180019.GA2884@localhost.localdomain \
--to=osalvador@suse.de \
--cc=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=anshuman.khandual@arm.com \
--cc=bp@alien8.de \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=duanxiongchun@bytedance.com \
--cc=hpa@zytor.com \
--cc=jroedel@suse.de \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mchehab+huawei@kernel.org \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=mingo@redhat.com \
--cc=naoya.horiguchi@nec.com \
--cc=oneukum@suse.com \
--cc=paulmck@kernel.org \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=rientjes@google.com \
--cc=song.bao.hua@hisilicon.com \
--cc=songmuchun@bytedance.com \
--cc=tglx@linutronix.de \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).