Patch series "Optimize the fast path of mas_store()", v4.

Add fast paths for mas_wr_append() and mas_wr_slot_store() respectively.
The newly added fast path of mas_wr_append() is used in fork() and how
much it benefits fork() depends on how many VMAs are duplicated.

Thanks Liam for the review.


This patch (of 4):

Add tests for all cases of mas_wr_append() and mas_wr_slot_store().

Link: https://lkml.kernel.org/r/20230628073657.75314-1-zhangpeng.00@bytedance.com
Link: https://lkml.kernel.org/r/20230628073657.75314-2-zhangpeng.00@bytedance.comSigned-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

ra->prev_pos tracks the last visited byte in the previous read request. 
It is used to check whether it is sequential read in ondemand_readahead
and thus affects the readahead window.

After commit 06c04442 ("mm/filemap.c: generic_file_buffered_read() now
uses find_get_pages_contig"), update logic of prev_pos is changed.  It
updates prev_pos after each return from filemap_get_pages().  But the read
request from user may be not fully completed at this point.  The updated
prev_pos impacts the subsequent readahead window.

The real problem is performance drop of fsck_msdos between linux-5.4 and
linux-5.15(also linux-6.4).  Comparing to linux-5.4,It spends about 110%
time and read 140% pages.  The read pattern of fsck_msdos is not fully
sequential.

Simplified read pattern of fsck_msdos likes below:
1.read at page offset 0xa,size 0x1000
2.read at other page offset like 0x20,size 0x1000
3.read at page offset 0xa,size 0x4000
4.read at page offset 0xe,size 0x1000

Here is the read status on linux-6.4:
1.after read at page offset 0xa,size 0x1000
    ->page ofs 0xa go into pagecache
2.after read at page offset 0x20,size 0x1000
    ->page ofs 0x20 go into pagecache
3.read at page offset 0xa,size 0x4000
    ->filemap_get_pages read ofs 0xa from pagecache and returns
    ->prev_pos is updated to 0xb and goto next loop
    ->filemap_get_pages tends to read ofs 0xb,size 0x3000
    ->initial_readahead case in ondemand_readahead since prev_pos is
      the same as request ofs.
    ->read 8 pages while async size is 5 pages
      (PageReadahead flag at page 0xe)
4.read at page offset 0xe,size 0x1000
    ->hit page 0xe with PageReadahead flag set,double the ra_size.
      read 16 pages while async size is 16 pages
Now it reads 24 pages while actually uses 5 pages

on linux-5.4:
1.the same as 6.4
2.the same as 6.4
3.read at page offset 0xa,size 0x4000
    ->read ofs 0xa from pagecache
    ->read ofs 0xb,size 0x3000 using page_cache_sync_readahead
      read 3 pages
    ->prev_pos is updated to 0xd before generic_file_buffered_read
      returns
4.read at page offset 0xe,size 0x1000
    ->initial_readahead case in ondemand_readahead since
      request ofs-prev_pos==1
    ->read 4 pages while async size is 3 pages

Now it reads 7 pages while actually uses 5 pages.

In above demo, the initial_readahead case is triggered by offset of user
request on linux-5.4.  While it may be triggered by update logic of
prev_pos on linux-6.4.

To fix the performance drop, update prev_pos after finishing one read
request.

Link: https://lkml.kernel.org/r/20230628110220.120134-1-haibo.li@mediatek.comSigned-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add a matrix for testing gup based on the current gup_test.  Only run the
matrix when -a is specified because it's a bit slow.

It covers:

  - Different types of huge pages: thp, hugetlb, or no huge page
  - Permissions: Write / Read-only
  - Fast-gup, with/without
  - Types of the GUP: pin / gup / longterm pins
  - Shared / Private memories
  - GUP size: 1 / 512 / random page sizes

Link: https://lkml.kernel.org/r/20230628215310.73782-9-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Allows to specify optional tests in run_vmtests.sh, where we can run time
consuming test matrix only when user specified "-a".

Link: https://lkml.kernel.org/r/20230628215310.73782-8-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Now __get_user_pages() should be well prepared to handle thp completely,
as long as hugetlb gup requests even without the hugetlb's special path.

Time to retire follow_hugetlb_page().

Tweak misc comments to reflect reality of follow_hugetlb_page()'s removal.

Link: https://lkml.kernel.org/r/20230628215310.73782-7-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The acceleration of THP was done with ctx.page_mask, however it'll be
ignored if **pages is non-NULL.

The old optimization was introduced in 2013 in 240aadee ("mm:
accelerate mm_populate() treatment of THP pages").  It didn't explain why
we can't optimize the **pages non-NULL case.  It's possible that at that
time the major goal was for mm_populate() which should be enough back
then.

Optimize thp for all cases, by properly looping over each subpage, doing
cache flushes, and boost refcounts / pincounts where needed in one go.

This can be verified using gup_test below:

  # chrt -f 1 ./gup_test -m 512 -t -L -n 1024 -r 10

Before:    13992.50 ( +-8.75%)
After:       378.50 (+-69.62%)

Link: https://lkml.kernel.org/r/20230628215310.73782-6-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The only path that doesn't use generic "**pages" handling is the gate vma.
Make it use the same path, meanwhile tune the next_page label upper to
cover "**pages" handling.  This prepares for THP handling for "**pages".

Link: https://lkml.kernel.org/r/20230628215310.73782-5-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

follow_page() doesn't need it, but we'll start to need it when unifying
gup for hugetlb.

Link: https://lkml.kernel.org/r/20230628215310.73782-4-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

follow_page() doesn't use FOLL_PIN, meanwhile hugetlb seems to not be the
target of FOLL_WRITE either.  However add the checks.

Namely, either the need to CoW due to missing write bit, or proper
unsharing on !AnonExclusive pages over R/O pins to reject the follow page.
That brings this function closer to follow_hugetlb_page().

So we don't care before, and also for now.  But we'll care if we switch
over slow-gup to use hugetlb_follow_page_mask().  We'll also care when to
return -EMLINK properly, as that's the gup internal api to mean "we should
unshare".  Not really needed for follow page path, though.

When at it, switching the try_grab_page() to use WARN_ON_ONCE(), to be
clear that it just should never fail.  When error happens, instead of
setting page==NULL, capture the errno instead.

Link: https://lkml.kernel.org/r/20230628215310.73782-3-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm/gup: Unify hugetlb, speed up thp", v4.

Hugetlb has a special path for slow gup that follow_page_mask() is
actually skipped completely along with faultin_page().  It's not only
confusing, but also duplicating a lot of logics that generic gup already
has, making hugetlb slightly special.

This patchset tries to dedup the logic, by first touching up the slow gup
code to be able to handle hugetlb pages correctly with the current follow
page and faultin routines (where we're mostly there..  due to 10 years ago
we did try to optimize thp, but half way done; more below), then at the
last patch drop the special path, then the hugetlb gup will always go the
generic routine too via faultin_page().

Note that hugetlb is still special for gup, mostly due to the pgtable
walking (hugetlb_walk()) that we rely on which is currently per-arch.  But
this is still one small step forward, and the diffstat might be a proof
too that this might be worthwhile.

Then for the "speed up thp" side: as a side effect, when I'm looking at
the chunk of code, I found that thp support is actually partially done. 
It doesn't mean that thp won't work for gup, but as long as **pages
pointer passed over, the optimization will be skipped too.  Patch 6 should
address that, so for thp we now get full speed gup.

For a quick number, "chrt -f 1 ./gup_test -m 512 -t -L -n 1024 -r 10"
gives me 13992.50us -> 378.50us.  Gup_test is an extreme case, but just to
show how it affects thp gups.


This patch (of 8):

Firstly, the no_page_table() is meaningless for hugetlb which is a no-op
there, because a hugetlb page always satisfies:

  - vma_is_anonymous() == false
  - vma->vm_ops->fault != NULL

So we can already safely remove it in hugetlb_follow_page_mask(), alongside
with the page* variable.

Meanwhile, what we do in follow_hugetlb_page() actually makes sense for a
dump: we try to fault in the page only if the page cache is already
allocated.  Let's do the same here for follow_page_mask() on hugetlb.

It should so far has zero effect on real dumps, because that still goes
into follow_hugetlb_page().  But this may start to influence a bit on
follow_page() users who mimics a "dump page" scenario, but hopefully in a
good way.  This also paves way for unifying the hugetlb gup-slow.

Link: https://lkml.kernel.org/r/20230628215310.73782-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20230628215310.73782-2-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A . Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

As a result of the patches "mm: Call arch_swap_restore() from
do_swap_page()" and "mm: Call arch_swap_restore() from unuse_pte()", there
are no circumstances in which a swapped-in page is installed in a page
table without first having arch_swap_restore() called on it.  Therefore,
we no longer need the logic in set_pte_at() that restores the tags, so
remove it.

Link: https://lkml.kernel.org/r/20230523004312.1807357-4-pcc@google.com
Link: https://linux-review.googlesource.com/id/I8ad54476f3b2d0144ccd8ce0c1d7a2963e5ff6f3Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kasan-dev@googlegroups.com
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: "Kuan-Ying Lee (李冠穎)" <Kuan-Ying.Lee@mediatek.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

We would like to move away from requiring architectures to restore
metadata from swap in the set_pte_at() implementation, as this is not only
error-prone but adds complexity to the arch-specific code.  This requires
us to call arch_swap_restore() before calling swap_free() whenever pages
are restored from swap.  We are currently doing so everywhere except in
unuse_pte(); do so there as well.

Link: https://lkml.kernel.org/r/20230523004312.1807357-3-pcc@google.com
Link: https://linux-review.googlesource.com/id/I68276653e612d64cde271ce1b5a99ae05d6bbc4fSigned-off-by: Peter Collingbourne <pcc@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: "Kuan-Ying Lee (李冠穎)" <Kuan-Ying.Lee@mediatek.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

All callers of show_free_areas() pass 0 and NULL, so we can directly use
show_mem() instead of show_free_areas(0, NULL), which could make
show_free_areas() a static function.

Link: https://lkml.kernel.org/r/20230630062253.189440-2-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

All callers of show_mem() pass 0 and NULL, so we can remove the two
arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in
show_mem().

Link: https://lkml.kernel.org/r/20230630062253.189440-1-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The memfd_create() syscall, enabled by CONFIG_MEMFD_CREATE, is useful on
its own even when not required by CONFIG_TMPFS or CONFIG_HUGETLBFS.

Split it into its own proper bool option that can be enabled by users.

Move that option into mm/ where the code itself also lies.  Also add
"select" statements to CONFIG_TMPFS and CONFIG_HUGETLBFS so they
automatically enable CONFIG_MEMFD_CREATE as before.

Link: https://lkml.kernel.org/r/20230630-config-memfd-v1-1-9acc3ae38b5a@weissschuh.netSigned-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Zhangjin Wu <falcon@tinylab.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

After converting the last user to folio_raw_mapping(), we can safely
remove the function.

Link: https://lkml.kernel.org/r/20230701032853.258697-3-zhangpeng362@huawei.comSigned-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

We can replace four implicit calls to compound_head() with one by using
folio.

Link: https://lkml.kernel.org/r/20230701032853.258697-2-zhangpeng362@huawei.comSigned-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Our test finds a WARN_ON in add_to_avail_list.  During add_to_avail_list,
avail_lists is already in swap_avail_heads, while leads to this WARN_ON.

Here is the simplified calltrace:

------------[ cut here ]------------
Call trace:
 add_to_avail_list+0xb8/0xc0
 swap_range_free+0x110/0x138
 swapcache_free_entries+0x100/0x1c0
 free_swap_slot+0xbc/0xe0
 put_swap_folio+0x1f0/0x2ec
 delete_from_swap_cache+0x6c/0xd0
 folio_free_swap+0xa4/0xe4
 __try_to_reclaim_swap+0x9c/0x190
 free_swap_and_cache+0x84/0x88
 unmap_page_range+0x31c/0x934
 unmap_single_vma.isra.0+0x48/0x84
 unmap_vmas+0x98/0x10c
 exit_mmap+0xa4/0x210
 mmput+0x88/0x158
 do_exit+0x284/0x970
 do_group_exit+0x34/0x90
 post_copy_siginfo_from_user32+0x0/0x1cc
 do_notify_resume+0x15c/0x470
 el0_svc+0x74/0x84
 el0t_64_sync_handler+0xb8/0xbc
 el0t_64_sync+0x190/0x194

During swapoff, try_to_unuse fails to alloc memory due to memory limit and
this leads to the failure of swapoff and causes re-insertion of swap space
back into swap_list.  During _enable_swap_info, this swap device is added
to avail list even this swap device if full.  At the same time, one entry
in this full swap device in released and we try to add this device into
avail list and find it is already in the avail list.  This causes this
WARN_ON.

To fix this.  Don't add to avail list is swap is full.

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20230627120833.2230766-3-mawupeng1@huawei.comSigned-off-by: Ma Wupeng <mawupeng1@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "fix WARN_ON in add_to_avail_list".


Empty check for plist_node is checked in add_to_avail_list and plist_add. 
Drop the duplicate one in add_to_avail_list.

Link: https://lkml.kernel.org/r/20230627120833.2230766-1-mawupeng1@huawei.com
Link: https://lkml.kernel.org/r/20230627120833.2230766-2-mawupeng1@huawei.comSigned-off-by: Ma Wupeng <mawupeng1@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using
the existing helper folio_next_index().

Link: https://lkml.kernel.org/r/20230627174349.491803-1-sidhartha.kumar@oracle.comSigned-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Since commit 633c0666 ("Memoryless nodes: drop one memoryless node boot
warning"), the warning for a node with no available memory is removed.
Update the corresponding comment.

Link: https://lkml.kernel.org/r/20230625033340.1054103-1-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The documentation of mt_next() claims that it starts the search at the
provided index.  That's incorrect as it starts the search after the
provided index.

The documentation of mt_find() is slightly confusing.  "Handles locking"
is not really helpful as it does not explain how the "locking" works. 
Also the documentation of index talks about a range, while in reality the
index is updated on a succesful search to the index of the found entry
plus one.

Fix similar issues for mt_find_after() and mt_prev().

Reword the confusing "Note: Will not return the zero entry." comment on
mt_for_each() and document @__index correctly.

Link: https://lkml.kernel.org/r/87ttw2n556.ffs@tglxSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A folio turns into a Workingset during:
1) shrink_active_list() placing the folio from active to inactive list.
2) When a workingset transition is happening during the folio refault.

And when Workingset is set on a folio, PSI for memory can be accounted
during a) That folio is being reclaimed and b) Refault of that folio,
for usual reclaims.

This accounting of PSI for memory is not consistent for reclaim +
refault operation between usual reclaim and madvise(COLD/PAGEOUT) which
deactivate or proactively reclaim a folio:
a) A folio started at inactive and moved to active as part of accesses.
Workingset is absent on the folio thus refault of it when reclaimed
through MADV_PAGEOUT operation doesn't account for PSI.

b) When the same folio transition from inactive->active and then to
inactive through shrink_active_list(). Workingset is set on the folio
thus refault of it when reclaimed through MADV_PAGEOUT operation
accounts for PSI.

c) When the same folio is part of active list directly as a result of
folio refault and this was a workingset folio prior to eviction.
Workingset is set on the folio thus the refault of it when reclaimed
through MADV_PAGEOUT/MADV_COLD operation accounts for PSI.

d) MADV_COLD transfers the folio from active list to inactive
list. Such folios may not have the Workingset thus refault operation on
such folio doesn't account for PSI.

As said above, refault operation caused because of MADV_PAGEOUT on a
folio is accounts for memory PSI in b) and c) but not in a). Refault
caused by the reclaim of a folio on which MADV_COLD is performed
accounts memory PSI in c) but not in d). These behaviours are
inconsistent w.r.t usual reclaim + refault operation. Make this PSI
accounting always consistent by turning a folio into a workingset one
whenever it is leaving the active list. Also, accounting of PSI on a
folio whenever it leaves the active list as part of the
MADV_COLD/PAGEOUT operation helps the users whether they are operating
on proper folios[1].

[1] https://lore.kernel.org/all/20230605180013.GD221380@cmpxchg.org/

Link: https://lkml.kernel.org/r/1688393201-11135-1-git-send-email-quic_charante@quicinc.comSigned-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Suggested-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Sai Manobhiram Manapragada <quic_smanapra@quicinc.com>
Reported-by: Pavan Kondeti <quic_pkondeti@quicinc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull spi fixes from Mark Brown:
 "A bunch of fixes for the Qualcomm QSPI driver, fixing multiple issues
  with the newly added DMA mode - it had a number of issues exposed when
  tested in a wider range of use cases, both race condition style issues
  and issues with different inputs to those that had been used in test"

* tag 'spi-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi-qcom-qspi: Add mem_ops to avoid PIO for badly sized reads
  spi: spi-qcom-qspi: Fallback to PIO for xfers that aren't multiples of 4 bytes
  spi: spi-qcom-qspi: Add DMA_CHAIN_DONE to ALL_IRQS
  spi: spi-qcom-qspi: Call dma_wmb() after setting up descriptors
  spi: spi-qcom-qspi: Use GFP_ATOMIC flag while allocating for descriptor
  spi: spi-qcom-qspi: Ignore disabled interrupts' status in isr

Merge tag 'regulator-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fixes from Mark Brown:
 "A couple of small fixes for the the mt6358 driver, fixing error
  reporting and a bootstrapping issue"

* tag 'regulator-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: mt6358: Fix incorrect VCN33 sync error message
  regulator: mt6358: Sync VCN33_* enable status after checking ID

Pull USB fixes from Greg KH:
 "Here are a set of USB driver fixes for 6.5-rc4. Include in here are:

   - new USB serial device ids

   - dwc3 driver fixes for reported issues

   - typec driver fixes for reported problems

   - gadget driver fixes

   - reverts of some problematic USB changes that went into -rc1

  All of these have been in linux-next with no reported problems"

* tag 'usb-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
  usb: misc: ehset: fix wrong if condition
  usb: dwc3: pci: skip BYT GPIO lookup table for hardwired phy
  usb: cdns3: fix incorrect calculation of ep_buf_size when more than one config
  usb: gadget: call usb_gadget_check_config() to verify UDC capability
  usb: typec: Use sysfs_emit_at when concatenating the string
  usb: typec: Iterate pds array when showing the pd list
  usb: typec: Set port->pd before adding device for typec_port
  usb: typec: qcom: fix return value check in qcom_pmic_typec_probe()
  Revert "usb: gadget: tegra-xudc: Fix error check in tegra_xudc_powerdomain_init()"
  Revert "usb: xhci: tegra: Fix error check"
  USB: gadget: Fix the memory leak in raw_gadget driver
  usb: gadget: core: remove unbalanced mutex_unlock in usb_gadget_activate
  Revert "usb: dwc3: core: Enable AutoRetry feature in the controller"
  Revert "xhci: add quirk for host controllers that don't update endpoint DCS"
  USB: quirks: add quirk for Focusrite Scarlett
  usb: xhci-mtk: set the dma max_seg_size
  MAINTAINERS: drop invalid usb/cdns3 Reviewer e-mail
  usb: dwc3: don't reset device side if dwc3 was configured as host-only
  usb: typec: ucsi: move typec_set_mode(TYPEC_STATE_SAFE) to ucsi_unregister_partner()
  usb: ohci-at91: Fix the unhandle interrupt when resume
  ...

Pull tty/serial fixes from Greg KH:
 "Here are some small TTY and serial driver fixes for 6.5-rc4 for some
  reported problems. Included in here is:

   - TIOCSTI fix for braille readers

   - documentation fix for minor numbers

   - MAINTAINERS update for new serial files in -rc1

   - minor serial driver fixes for reported problems

  All of these have been in linux-next with no reported problems"

* tag 'tty-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_dw: Preserve original value of DLF register
  tty: serial: sh-sci: Fix sleeping in atomic context
  serial: sifive: Fix sifive_serial_console_setup() section
  Documentation: devices.txt: reconcile serial/ucc_uart minor numers
  MAINTAINERS: Update TTY layer for lists and recently added files
  tty: n_gsm: fix UAF in gsm_cleanup_mux
  TIOCSTI: always enable for CAP_SYS_ADMIN

Pull staging driver fixes from Greg KH:
 "Here are three small staging driver fixes for 6.5-rc4 that resolve
  some reported problems. These fixes are:

   - fix for an old bug in the r8712 driver

   - fbtft driver fix for a spi device

   - potential overflow fix in the ks7010 driver

  All of these have been in linux-next with no reported problems"

* tag 'staging-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ks7010: potential buffer overflow in ks_wlan_set_encode_ext()
  staging: fbtft: ili9341: use macro FBTFT_REGISTER_SPI_DRIVER
  staging: r8712: Fix memory leak in _r8712_init_xmit_priv()

Pull char driver and Documentation fixes from Greg KH:
 "Here is a char driver fix and some documentation updates for 6.5-rc4
  that contain the following changes:

   - sram/genalloc bugfix for reported problem

   - security-bugs.rst update based on recent discussions

   - embargoed-hardware-issues minor cleanups and then partial revert
     for the project/company lists

  All of these have been in linux-next for a while with no reported
  problems, and the documentation updates have all been reviewed by the
  relevant developers"

* tag 'char-misc-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc/genalloc: Name subpools by of_node_full_name()
  Documentation: embargoed-hardware-issues.rst: add AMD to the list
  Documentation: embargoed-hardware-issues.rst: clean out empty and unused entries
  Documentation: security-bugs.rst: clarify CVE handling
  Documentation: security-bugs.rst: update preferences when dealing with the linux-distros group

Merge tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probe fixes from Masami Hiramatsu:

 - probe-events: add NULL check for some BTF API calls which can return
   error code and NULL.

 - ftrace selftests: check fprobe and kprobe event correctly. This fixes
   a miss condition of the test command.

 - kprobes: do not allow probing functions that start with "__cfi_" or
   "__pfx_" since those are auto generated for kernel CFI and not
   executed.

* tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Prohibit probing on CFI preamble symbol
  selftests/ftrace: Fix to check fprobe event eneblement
  tracing/probes: Fix to add NULL check for BTF APIs

Pull kvm fixes from Paolo Bonzini:
 "x86:

   - Do not register IRQ bypass consumer if posted interrupts not
     supported

   - Fix missed device interrupt due to non-atomic update of IRR

   - Use GFP_KERNEL_ACCOUNT for pid_table in ipiv

   - Make VMREAD error path play nice with noinstr

   - x86: Acquire SRCU read lock when handling fastpath MSR writes

   - Support linking rseq tests statically against glibc 2.35+

   - Fix reference count for stats file descriptors

   - Detect userspace setting invalid CR0

  Non-KVM:

   - Remove coccinelle script that has caused multiple confusion
     ("debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE()
     usage", acked by Greg)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: selftests: Expand x86's sregs test to cover illegal CR0 values
  KVM: VMX: Don't fudge CR0 and CR4 for restricted L2 guest
  KVM: x86: Disallow KVM_SET_SREGS{2} if incoming CR0 is invalid
  Revert "debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage"
  KVM: selftests: Verify stats fd is usable after VM fd has been closed
  KVM: selftests: Verify stats fd can be dup()'d and read
  KVM: selftests: Verify userspace can create "redundant" binary stats files
  KVM: selftests: Explicitly free vcpus array in binary stats test
  KVM: selftests: Clean up stats fd in common stats_test() helper
  KVM: selftests: Use pread() to read binary stats header
  KVM: Grab a reference to KVM for VM and vCPU stats file descriptors
  selftests/rseq: Play nice with binaries statically linked against glibc 2.35+
  Revert "KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"
  KVM: x86: Acquire SRCU read lock when handling fastpath MSR writes
  KVM: VMX: Use vmread_error() to report VM-Fail in "goto" path
  KVM: VMX: Make VMREAD error path play nice with noinstr
  KVM: x86/irq: Conditionally register IRQ bypass consumer again
  KVM: X86: Use GFP_KERNEL_ACCOUNT for pid_table in ipiv
  KVM: x86: check the kvm_cpu_get_interrupt result before using it
  KVM: x86: VMX: set irr_pending in kvm_apic_update_irr
  ...

Pull locking fix from Borislav Petkov:

 - Fix a rtmutex race condition resulting from sharing of the sort key
   between the lock waiters and the PI chain tree (->pi_waiters) of a
   task by giving each tree their own sort key

* tag 'locking_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Fix task->pi_waiters integrity

Pull x86 fixes from Borislav Petkov:

 - AMD's automatic IBRS doesn't enable cross-thread branch target
   injection protection (STIBP) for user processes. Enable STIBP on such
   systems.

 - Do not delete (but put the ref instead) of AMD MCE error thresholding
   sysfs kobjects when destroying them in order not to delete the kernfs
   pointer prematurely

 - Restore annotation in ret_from_fork_asm() in order to fix kthread
   stack unwinding from being marked as unreliable and thus breaking
   livepatching

* tag 'x86_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Enable STIBP on AMD if Automatic IBRS is enabled
  x86/MCE/AMD: Decrement threshold_bank refcount when removing threshold blocks
  x86: Fix kthread unwind

Pull irq fixes from Borislav Petkov:

 - Work around an erratum on GIC700, where a race between a CPU handling
   a wake-up interrupt, a change of affinity, and another CPU going to
   sleep can result in a lack of wake-up event on the next interrupt

 - Fix the locking required on a VPE for GICv4

 - Enable Rockchip 3588001 erratum workaround for RK3588S

 - Fix the irq-bcm6345-l1 assumtions of the boot CPU always be the first
   CPU in the system

* tag 'irq_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3: Workaround for GIC-700 erratum 2941627
  irqchip/gic-v3: Enable Rockchip 3588001 erratum workaround for RK3588S
  irqchip/gic-v4.1: Properly lock VPEs when doing a directLPI invalidation
  irq-bcm6345-l1: Do not assume a fixed block to cpu mapping

Pull smb client fixes from Steve French:
 "Four small SMB3 client fixes:

   - two reconnect fixes (to address the case where non-default
     iocharset gets incorrectly overridden at reconnect with the
     default charset)

   - fix for NTLMSSP_AUTH request setting a flag incorrectly)

   - Add missing check for invalid tlink (tree connection) in ioctl"

* tag '6.5-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: add missing return value check for cifs_sb_tlink
  smb3: do not set NTLMSSP_VERSION flag for negotiate not auth request
  cifs: fix charset issue in reconnection
  fs/nls: make load_nls() take a const parameter

Pull tracing fixes from Steven Rostedt:

 - Fix to /sys/kernel/tracing/per_cpu/cpu*/stats read and entries.

   If a resize shrinks the buffer it clears the read count to notify
   readers that they need to reset. But the read count is also used for
   accounting and this causes the numbers to be off. Instead, create a
   separate variable to use to notify readers to reset.

 - Fix the ref counts of the "soft disable" mode. The wrong value was
   used for testing if soft disable mode should be enabled or disable,
   but instead, just change the logic to do the enable and disable in
   place when the SOFT_MODE is set or cleared.

 - Several kernel-doc fixes

 - Removal of unused external declarations

* tag 'trace-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix warning in trace_buffered_event_disable()
  ftrace: Remove unused extern declarations
  tracing: Fix kernel-doc warnings in trace_seq.c
  tracing: Fix kernel-doc warnings in trace_events_trigger.c
  tracing/synthetic: Fix kernel-doc warnings in trace_events_synth.c
  ring-buffer: Fix kernel-doc warnings in ring_buffer.c
  ring-buffer: Fix wrong stat of cpu_buffer->read

Commit a2225d93 ("autofs: remove left-over autofs4 stubs")
promised the removal of the fs/autofs/Kconfig fragment for AUTOFS4_FS
within a couple of releases, but five years later this still has not
happened yet, and AUTOFS4_FS is still enabled in 63 defconfigs.

Get rid of it mechanically:

   git grep -l CONFIG_AUTOFS4_FS -- '*defconfig' |
       xargs sed -i 's/AUTOFS4_FS/AUTOFS_FS/'

Also just remove the AUTOFS4_FS config option stub.  Anybody who hasn't
regenerated their config file in the last five years will need to just
get the new name right when they do.
Signed-off-by: Sven Joachim <svenjoac@gmx.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'loongarch-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Some bug fixes for build system, builtin cmdline handling, bpf and
  {copy, clear}_user, together with a trivial cleanup"

* tag 'loongarch-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Cleanup __builtin_constant_p() checking for cpu_has_*
  LoongArch: BPF: Fix check condition to call lu32id in move_imm()
  LoongArch: BPF: Enable bpf_probe_read{, str}() on LoongArch
  LoongArch: Fix return value underflow in exception path
  LoongArch: Fix CMDLINE_EXTEND and CMDLINE_BOOTLOADER handling
  LoongArch: Fix module relocation error with binutils 2.41
  LoongArch: Only fiddle with CHECKFLAGS if `need-compiler'

Add coverage to x86's set_sregs_test to verify KVM rejects vendor-agnostic
illegal CR0 values, i.e. CR0 values whose legality doesn't depend on the
current VMX mode.  KVM historically has neglected to reject bad CR0s from
userspace, i.e. would happily accept a completely bogus CR0 via
KVM_SET_SREGS{2}.

Punt VMX specific subtests to future work, as they would require quite a
bit more effort, and KVM gets coverage for CR0 checks in general through
other means, e.g. KVM-Unit-Tests.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230613203037.1968489-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>