From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Ira Weiny" <ira.weiny@intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Michal Hocko" <mhocko@suse.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Jason Gunthorpe" <jgg@mellanox.com>,
"Sasha Levin" <sashal@kernel.org>,
linux-mm@kvack.org
Subject: [PATCH AUTOSEL 5.2 102/171] mm/swap: fix release_pages() when releasing devmap pages
Date: Thu, 18 Jul 2019 23:55:33 -0400 [thread overview]
Message-ID: <20190719035643.14300-102-sashal@kernel.org> (raw)
In-Reply-To: <20190719035643.14300-1-sashal@kernel.org>
From: Ira Weiny <ira.weiny@intel.com>
[ Upstream commit c5d6c45e90c49150670346967971e14576afd7f1 ]
release_pages() is an optimized version of a loop around put_page().
Unfortunately for devmap pages the logic is not entirely correct in
release_pages(). This is because device pages can be more than type
MEMORY_DEVICE_PUBLIC. There are in fact 4 types, private, public, FS DAX,
and PCI P2PDMA. Some of these have specific needs to "put" the page while
others do not.
This logic to handle any special needs is contained in
put_devmap_managed_page(). Therefore all devmap pages should be processed
by this function where we can contain the correct logic for a page put.
Handle all device type pages within release_pages() by calling
put_devmap_managed_page() on all devmap pages. If
put_devmap_managed_page() returns true the page has been put and we
continue with the next page. A false return of put_devmap_managed_page()
means the page did not require special processing and should fall to
"normal" processing.
This was found via code inspection while determining if release_pages()
and the new put_user_pages() could be interchangeable.[1]
[1] https://lkml.kernel.org/r/20190523172852.GA27175@iweiny-DESK2.sc.intel.com
Link: https://lkml.kernel.org/r/20190605214922.17684-1-ira.weiny@intel.com
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/swap.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/mm/swap.c b/mm/swap.c
index 7ede3eddc12a..607c48229a1d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -740,15 +740,20 @@ void release_pages(struct page **pages, int nr)
if (is_huge_zero_page(page))
continue;
- /* Device public page can not be huge page */
- if (is_device_public_page(page)) {
+ if (is_zone_device_page(page)) {
if (locked_pgdat) {
spin_unlock_irqrestore(&locked_pgdat->lru_lock,
flags);
locked_pgdat = NULL;
}
- put_devmap_managed_page(page);
- continue;
+ /*
+ * ZONE_DEVICE pages that return 'false' from
+ * put_devmap_managed_page() do not require special
+ * processing, and instead, expect a call to
+ * put_page_testzero().
+ */
+ if (put_devmap_managed_page(page))
+ continue;
}
page = compound_head(page);
--
2.20.1
next prev parent reply other threads:[~2019-07-19 4:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190719035643.14300-1-sashal@kernel.org>
2019-07-19 3:54 ` [PATCH AUTOSEL 5.2 045/171] mm/hmm: fix use after free with struct hmm in the mmu notifiers Sasha Levin
2019-07-19 3:55 ` Sasha Levin [this message]
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 156/171] mm/kmemleak.c: fix check for softirq context Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 158/171] mm/mincore.c: fix race between swapoff and mincore Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 159/171] mm/gup.c: mark undo_dev_pagemap as __maybe_unused Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 160/171] mm/gup.c: remove some BUG_ONs from get_gate_page() Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 162/171] mm/mmu_notifier: use hlist_add_head_rcu() Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 170/171] mm: use down_read_killable for locking mmap_sem in access_remote_vm Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 171/171] mm, swap: fix race between swapoff and some swap operations Sasha Levin
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=20190719035643.14300-102-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=dan.j.williams@intel.com \
--cc=ira.weiny@intel.com \
--cc=jgg@mellanox.com \
--cc=jglisse@redhat.com \
--cc=jhubbard@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=stable@vger.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).