From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>,
Dave Hansen <dave.hansen@intel.com>,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@gentwo.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Jerome Marchand <jmarchan@redhat.com>,
Yang Shi <yang.shi@linaro.org>,
Sasha Levin <sasha.levin@oracle.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: THP-enabled filesystem vs. FALLOC_FL_PUNCH_HOLE
Date: Mon, 7 Mar 2016 02:33:30 +0300 [thread overview]
Message-ID: <20160306233330.GA23851@node.shutemov.name> (raw)
In-Reply-To: <20160306230336.GE11282@dastard>
On Mon, Mar 07, 2016 at 10:03:36AM +1100, Dave Chinner wrote:
> On Sun, Mar 06, 2016 at 03:30:34AM +0300, Kirill A. Shutemov wrote:
> > On Sun, Mar 06, 2016 at 09:38:11AM +1100, Dave Chinner wrote:
> > > And it's not just hole punching that has this problem. Direct IO is
> > > going to have the same issue with invalidation of the mapped ranges
> > > over the IO being done. XFS already WARNs when page cache
> > > invalidation fails with EBUSY in direct IO, because that is
> > > indicative of an application with a potential data corruption vector
> > > and there's nothing we can do in the kernel code to prevent it.
> >
> > My current understanding is that for filesystems with persistent storage,
> > in order to make THP any useful, we would need to implement writeback
> > without splitting the huge page.
>
> Algorithmically it is no different to filesytem block size < page
> size writeback.
>
> > At the moment, I have no idea how hard it would be..
>
> THP support would effectively require us to remove PAGE_CACHE_SIZE
> assumptions from all of the filesystem and buffer code. That's a
> large chunk of work e.g. fs/buffer.c and any filesystem that uses
> bufferheads for tracking filesystem block state through the page
> cache.
I'll try to learn more about the code before the summit.
I guess it's something worth descussion in person.
--
Kirill A. Shutemov
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
prev parent reply other threads:[~2016-03-06 23:33 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 16:51 [PATCHv3 00/29] huge tmpfs implementation using compound pages Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 01/29] rmap: introduce rmap_walk_locked() Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 02/29] rmap: extend try_to_unmap() to be usable by split_huge_page() Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 03/29] mm: make remove_migration_ptes() beyond mm/migration.c Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 04/29] thp: rewrite freeze_page()/unfreeze_page() with generic rmap walkers Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 05/29] mm: do not pass mm_struct into handle_mm_fault Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 06/29] mm: introduce fault_env Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 07/29] mm: postpone page table allocation until we have page to map Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 08/29] rmap: support file thp Kirill A. Shutemov
2016-03-03 16:51 ` [PATCHv3 09/29] mm: introduce do_set_pmd() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 10/29] mm, rmap: account file thp pages Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 11/29] thp, vmstats: add counters for huge file pages Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 12/29] thp: support file pages in zap_huge_pmd() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 13/29] thp: handle file pages in split_huge_pmd() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 14/29] thp: handle file COW faults Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 15/29] thp: handle file pages in mremap() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 16/29] thp: skip file huge pmd on copy_huge_pmd() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 17/29] thp: prepare change_huge_pmd() for file thp Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 18/29] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 19/29] thp: file pages support for split_huge_page() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 20/29] thp, mlock: do not mlock PTE-mapped file huge pages Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 21/29] vmscan: split file huge pages before paging them out Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 22/29] page-flags: relax policy for PG_mappedtodisk and PG_reclaim Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 23/29] radix-tree: implement radix_tree_maybe_preload_order() Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 24/29] filemap: prepare find and delete operations for huge pages Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 25/29] truncate: handle file thp Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 26/29] shmem: prepare huge= mount option and sysfs knob Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 27/29] shmem: get_unmapped_area align huge page Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 28/29] shmem: add huge pages support Kirill A. Shutemov
2016-03-03 16:52 ` [PATCHv3 29/29] shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings Kirill A. Shutemov
2016-03-04 4:20 ` [PATCHv3 00/29] huge tmpfs implementation using compound pages Sasha Levin
2016-03-04 22:53 ` Kirill A. Shutemov
2016-03-04 11:26 ` THP-enabled filesystem vs. FALLOC_FL_PUNCH_HOLE Kirill A. Shutemov
2016-03-04 17:40 ` Dave Hansen
2016-03-04 19:38 ` Hugh Dickins
2016-03-04 22:48 ` Kirill A. Shutemov
2016-03-04 23:05 ` Dave Chinner
2016-03-04 23:24 ` Kirill A. Shutemov
2016-03-05 22:38 ` Dave Chinner
2016-03-06 0:30 ` Kirill A. Shutemov
2016-03-06 23:03 ` Dave Chinner
2016-03-06 23:33 ` Kirill A. Shutemov [this message]
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=20160306233330.GA23851@node.shutemov.name \
--to=kirill@shutemov.name \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=cl@gentwo.org \
--cc=dave.hansen@intel.com \
--cc=david@fromorbit.com \
--cc=hughd@google.com \
--cc=jmarchan@redhat.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=n-horiguchi@ah.jp.nec.com \
--cc=sasha.levin@oracle.com \
--cc=vbabka@suse.cz \
--cc=yang.shi@linaro.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).