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Currently, prep_new_huge_page() performs two functions. It sets the
right state for a new hugetlb, and increases the hstate's counters to
account for the new page.
Let us split its functionality into two separate functions, decoupling
the handling of the counters from initializing a hugepage. The outcome
is having __prep_new_huge_page(), which only initializes the page , and
__prep_account_new_huge_page(), which adds the new page to the hstate's
counters.
This allows us to be able to set a hugetlb without having to worry about
the counter/locking. It will prove useful in the next patch.
prep_new_huge_page() still calls both functions.
Link: https://lkml.kernel.org/r/20210419075413.1064-5-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pages allocated via the page allocator or CMA get its private field
cleared by means of post_alloc_hook().
Pages allocated during boot, that is directly from the memblock
allocator, get cleared by paging_init()-> .. ->memmap_init_zone-> ..
->__init_single_page() before any memblock allocation.
Based on this ground, let us remove the clearing of the flag from
prep_new_huge_page() as it is not needed. This was a leftover from
commit 6c03714901 ("hugetlb: convert PageHugeFreed to HPageFreed
flag").
Previously the explicit clearing was necessary because compound
allocations do not get this initialization (see prep_compound_page).
Link: https://lkml.kernel.org/r/20210419075413.1064-4-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_pool_huge_page was called with hugetlb_lock held. It would remove
a hugetlb page, and then free the corresponding pages to the lower level
allocators such as buddy. free_pool_huge_page was called in a loop to
remove hugetlb pages and these loops could hold the hugetlb_lock for a
considerable time.
Create new routine remove_pool_huge_page to replace free_pool_huge_page.
remove_pool_huge_page will remove the hugetlb page, and it must be
called with the hugetlb_lock held. It will return the removed page and
it is the responsibility of the caller to free the page to the lower
level allocators. The hugetlb_lock is dropped before freeing to these
allocators which results in shorter lock hold times.
Add new helper routine to call update_and_free_page for a list of pages.
Note: Some changes to the routine return_unused_surplus_pages are in
need of explanation. Commit e5bbc8a6c9 ("mm/hugetlb.c: fix
reservation race when freeing surplus pages") modified this routine to
address a race which could occur when dropping the hugetlb_lock in the
loop that removes pool pages. Accounting changes introduced in that
commit were subtle and took some thought to understand. This commit
removes the cond_resched_lock() and the potential race. Therefore,
remove the subtle code and restore the more straight forward accounting
effectively reverting the commit.
Link: https://lkml.kernel.org/r/20210409205254.242291-7-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The helper routine hstate_next_node_to_alloc accesses and modifies the
hstate variable next_nid_to_alloc. The helper is used by the routines
alloc_pool_huge_page and adjust_pool_surplus. adjust_pool_surplus is
called with hugetlb_lock held. However, alloc_pool_huge_page can not be
called with the hugetlb lock held as it will call the page allocator.
Two instances of alloc_pool_huge_page could be run in parallel or
alloc_pool_huge_page could run in parallel with adjust_pool_surplus
which may result in the variable next_nid_to_alloc becoming invalid for
the caller and pages being allocated on the wrong node.
Both alloc_pool_huge_page and adjust_pool_surplus are only called from
the routine set_max_huge_pages after boot. set_max_huge_pages is only
called as the reusult of a user writing to the proc/sysfs nr_hugepages,
or nr_hugepages_mempolicy file to adjust the number of hugetlb pages.
It makes little sense to allow multiple adjustment to the number of
hugetlb pages in parallel. Add a mutex to the hstate and use it to only
allow one hugetlb page adjustment at a time. This will synchronize
modifications to the next_nid_to_alloc variable.
Link: https://lkml.kernel.org/r/20210409205254.242291-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The resv_map could be NULL since this routine can be called in the evict
inode path for all hugetlbfs inodes and we will have chg = 0 in this case.
But (chg - freed) won't go negative as Mike pointed out:
"If resv_map is NULL, then no hugetlb pages can be allocated/associated
with the file. As a result, remove_inode_hugepages will never find any
huge pages associated with the inode and the passed value 'freed' will
always be zero."
Add a comment clarifying this to make it clear and also avoid confusion.
Link: https://lkml.kernel.org/r/20210410072348.20437-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Feilong Lin <linfeilong@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vma_resv_map(vma) checks if a reserve map is associated with the vma.
The routine vma_needs_reservation() will check vma_resv_map(vma) and
return 1 if no reserv map is present. map_chg is set to the return
value of vma_needs_reservation(). Therefore, !vma_resv_map(vma) is
redundant in the expression:
map_chg || avoid_reserve || !vma_resv_map(vma);
Remove the redundant check.
[Thanks Mike Kravetz for reshaping this commit message!]
Link: https://lkml.kernel.org/r/20210301104726.45159-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current implementation of hugetlb_cgroup for shared mappings could
have different behavior. Consider the following two scenarios:
1.Assume initial css reference count of hugetlb_cgroup is 1:
1.1 Call hugetlb_reserve_pages with from = 1, to = 2. So css reference
count is 2 associated with 1 file_region.
1.2 Call hugetlb_reserve_pages with from = 2, to = 3. So css reference
count is 3 associated with 2 file_region.
1.3 coalesce_file_region will coalesce these two file_regions into
one. So css reference count is 3 associated with 1 file_region
now.
2.Assume initial css reference count of hugetlb_cgroup is 1 again:
2.1 Call hugetlb_reserve_pages with from = 1, to = 3. So css reference
count is 2 associated with 1 file_region.
Therefore, we might have one file_region while holding one or more css
reference counts. This inconsistency could lead to imbalanced css_get()
and css_put() pair. If we do css_put one by one (i.g. hole punch case),
scenario 2 would put one more css reference. If we do css_put all
together (i.g. truncate case), scenario 1 will leak one css reference.
The imbalanced css_get() and css_put() pair would result in a non-zero
reference when we try to destroy the hugetlb cgroup. The hugetlb cgroup
directory is removed __but__ associated resource is not freed. This
might result in OOM or can not create a new hugetlb cgroup in a busy
workload ultimately.
In order to fix this, we have to make sure that one file_region must
hold exactly one css reference. So in coalesce_file_region case, we
should release one css reference before coalescence. Also only put css
reference when the entire file_region is removed.
The last thing to note is that the caller of region_add() will only hold
one reference to h_cg->css for the whole contiguous reservation region.
But this area might be scattered when there are already some
file_regions reside in it. As a result, many file_regions may share only
one h_cg->css reference. In order to ensure that one file_region must
hold exactly one css reference, we should do css_get() for each
file_region and release the reference held by caller when they are done.
[linmiaohe@huawei.com: fix imbalanced css_get and css_put pair for shared mappings]
Link: https://lkml.kernel.org/r/20210316023002.53921-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210301120540.37076-1-linmiaohe@huawei.com
Fixes: 075a61d07a ("hugetlb_cgroup: add accounting for shared mappings")
Reported-by: kernel test robot <lkp@intel.com> (auto build test ERROR)
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Wanpeng Li <liwp.linux@gmail.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gerald Schaefer reported a panic on s390 in hugepage_subpool_put_pages()
with linux-next 5.12.0-20210222.
Call trace:
hugepage_subpool_put_pages.part.0+0x2c/0x138
__free_huge_page+0xce/0x310
alloc_pool_huge_page+0x102/0x120
set_max_huge_pages+0x13e/0x350
hugetlb_sysctl_handler_common+0xd8/0x110
hugetlb_sysctl_handler+0x48/0x58
proc_sys_call_handler+0x138/0x238
new_sync_write+0x10e/0x198
vfs_write.part.0+0x12c/0x238
ksys_write+0x68/0xf8
do_syscall+0x82/0xd0
__do_syscall+0xb4/0xc8
system_call+0x72/0x98
This is a result of the change which moved the hugetlb page subpool
pointer from page->private to page[1]->private. When new pages are
allocated from the buddy allocator, the private field of the head
page will be cleared, but the private field of subpages is not modified.
Therefore, old values may remain.
Fix by initializing hugetlb page subpool pointer in prep_new_huge_page().
Link: https://lkml.kernel.org/r/20210223215544.313871-1-mike.kravetz@oracle.com
Fixes: f1280272ae4d ("hugetlb: use page.private for hugetlb specific page flags")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the new hugetlb page specific flag HPageMigratable to replace the
page_huge_active interfaces. By it's name, page_huge_active implied that
a huge page was on the active list. However, that is not really what code
checking the flag wanted to know. It really wanted to determine if the
huge page could be migrated. This happens when the page is actually added
to the page cache and/or task page table. This is the reasoning behind
the name change.
The VM_BUG_ON_PAGE() calls in the *_huge_active() interfaces are not
really necessary as we KNOW the page is a hugetlb page. Therefore, they
are removed.
The routine page_huge_active checked for PageHeadHuge before testing the
active bit. This is unnecessary in the case where we hold a reference or
lock and know it is a hugetlb head page. page_huge_active is also called
without holding a reference or lock (scan_movable_pages), and can race
with code freeing the page. The extra check in page_huge_active shortened
the race window, but did not prevent the race. Offline code calling
scan_movable_pages already deals with these races, so removing the check
is acceptable. Add comment to racy code.
[songmuchun@bytedance.com: remove set_page_huge_active() declaration from include/linux/hugetlb.h]
Link: https://lkml.kernel.org/r/CAMZfGtUda+KoAZscU0718TN61cSFwp4zy=y2oZ=+6Z2TAZZwng@mail.gmail.com
Link: https://lkml.kernel.org/r/20210122195231.324857-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "create hugetlb flags to consolidate state", v3.
While discussing a series of hugetlb fixes in [1], it became evident that
the hugetlb specific page state information is stored in a somewhat
haphazard manner. Code dealing with state information would be easier to
read, understand and maintain if this information was stored in a
consistent manner.
This series uses page.private of the hugetlb head page for storing a set
of hugetlb specific page flags. Routines are priovided for test, set and
clear of the flags.
[1] https://lore.kernel.org/r/20210106084739.63318-1-songmuchun@bytedance.com
This patch (of 4):
As hugetlbfs evolved, state information about hugetlb pages was added.
One 'convenient' way of doing this was to use available fields in tail
pages. Over time, it has become difficult to know the meaning or contents
of fields simply by looking at a small bit of code. Sometimes, the naming
is just confusing. For example: The PagePrivate flag indicates a huge
page reservation was consumed and needs to be restored if an error is
encountered and the page is freed before it is instantiated. The
page.private field contains the pointer to a subpool if the page is
associated with one.
In an effort to make the code more readable, use page.private to contain
hugetlb specific page flags. These flags will have test, set and clear
functions similar to those used for 'normal' page flags. More
importantly, an enum of flag values will be created with names that
actually reflect their purpose.
In this patch,
- Create infrastructure for hugetlb specific page flag functions
- Move subpool pointer to page[1].private to make way for flags
Create routines with meaningful names to modify subpool field
- Use new HPageRestoreReserve flag instead of PagePrivate
Conversion of other state information will happen in subsequent patches.
Link: https://lkml.kernel.org/r/20210122195231.324857-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20210122195231.324857-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For a given hugepage backing a VA, there's a rather ineficient loop which
is solely responsible for storing subpages in GUP @pages/@vmas array. For
each subpage we check whether it's within range or size of @pages and keep
increment @pfn_offset and a couple other variables per subpage iteration.
Simplify this logic and minimize the cost of each iteration to just store
the output page/vma. Instead of incrementing number of @refs iteratively,
we do it through pre-calculation of @refs and only with a tight loop for
storing pinned subpages/vmas.
Additionally, retain existing behaviour with using mem_map_offset() when
recording the subpages for configurations that don't have a contiguous
mem_map.
pinning consequently improves bringing us close to
{pin,get}_user_pages_fast:
- 16G with 1G huge page size
gup_test -f /mnt/huge/file -m 16384 -r 30 -L -S -n 512 -w
PIN_LONGTERM_BENCHMARK: ~12.8k us -> ~5.8k us
PIN_FAST_BENCHMARK: ~3.7k us
Link: https://lkml.kernel.org/r/20210128182632.24562-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/hugetlb: follow_hugetlb_page() improvements", v2.
While looking at ZONE_DEVICE struct page reuse particularly the last
patch[0], I found two possible improvements for follow_hugetlb_page()
which is solely used for get_user_pages()/pin_user_pages().
The first patch batches page refcount updates while the second tidies up
storing the subpages/vmas. Both together bring the cost of slow variant
of gup() cost from ~87.6k usecs to ~5.8k usecs.
libhugetlbfs tests seem to pass as well gup_test benchmarks with hugetlbfs
vmas.
This patch (of 2):
follow_hugetlb_page() once it locks the pmd/pud, checks all its N subpages
in a huge page and grabs a reference for each one. Similar to gup-fast,
have follow_hugetlb_page() grab the head page refcount only after counting
all its subpages that are part of the just faulted huge page.
Consequently we reduce the number of atomics necessary to pin said huge
page, which improves non-fast gup() considerably:
- 16G with 1G huge page size
gup_test -f /mnt/huge/file -m 16384 -r 10 -L -S -n 512 -w
PIN_LONGTERM_BENCHMARK: ~87.6k us -> ~12.8k us
Link: https://lkml.kernel.org/r/20210128182632.24562-1-joao.m.martins@oracle.com
Link: https://lkml.kernel.org/r/20210128182632.24562-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a hugetlbfs filesystem is created with the min_size option and
without the size option, used_hpages is always 0 and might lead to
release subpool prematurely because it indicates no pages are used now
while there might be.
In order to fix this issue, we should check used_hpages == 0 iff
max_hpages accounting is enabled. As max_hpages accounting should be
enabled in most common case, this is not worth a Cc stable.
[mike.kravetz@oracle.com: new changelog]
Link: https://lkml.kernel.org/r/20210126115510.53374-1-linmiaohe@huawei.com
Signed-off-by: Hongxiang Lou <louhongxiang@huawei.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current code would unnecessarily expand the address range. Consider
one example, (start, end) = (1G-2M, 3G+2M), and (vm_start, vm_end) =
(1G-4M, 3G+4M), the expected adjustment should be keep (1G-2M, 3G+2M)
without expand. But the current result will be (1G-4M, 3G+4M). Actually,
the range (1G-4M, 1G) and (3G, 3G+4M) would never been involved in pmd
sharing.
After this patch, we will check that the vma span at least one PUD aligned
size and the start,end range overlap the aligned range of vma.
With above example, the aligned vma range is (1G, 3G), so if (start, end)
range is within (1G-4M, 1G), or within (3G, 3G+4M), then no adjustment to
both start and end. Otherwise, we will have chance to adjust start
downwards or end upwards without exceeding (vm_start, vm_end).
Mike:
: The 'adjusted range' is used for calls to mmu notifiers and cache(tlb)
: flushing. Since the current code unnecessarily expands the range in some
: cases, more entries than necessary would be flushed. This would/could
: result in performance degradation. However, this is highly dependent on
: the user runtime. Is there a combination of vma layout and calls to
: actually hit this issue? If the issue is hit, will those entries
: unnecessarily flushed be used again and need to be unnecessarily reloaded?
Link: https://lkml.kernel.org/r/20210104081631.2921415-1-lixinhai.lxh@gmail.com
Fixes: 75802ca663 ("mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible")
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull tlb gather updates from Ingo Molnar:
"Theses fix MM (soft-)dirty bit management in the procfs code & clean
up the TLB gather API"
* tag 'core-mm-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ldt: Use tlb_gather_mmu_fullmm() when freeing LDT page-tables
tlb: arch: Remove empty __tlb_remove_tlb_entry() stubs
tlb: mmu_gather: Remove start/end arguments from tlb_gather_mmu()
tlb: mmu_gather: Introduce tlb_gather_mmu_fullmm()
tlb: mmu_gather: Remove unused start/end arguments from tlb_finish_mmu()
mm: proc: Invalidate TLB after clearing soft-dirty page state
