linux-toradex.git/arch/hexagon/mm, branch v5.11

mm/hexagon: use general page fault accounting

2020-08-12T17:58:03+00:00

Use the general page fault accounting by passing regs into
handle_mm_fault().  It naturally solve the issue of multiple page fault
accounting when page fault retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the
other two perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in
handle_mm_fault().

Signed-off-by: Peter Xu 
Signed-off-by: Andrew Morton 
Acked-by: Brian Cain 
Link: http://lkml.kernel.org/r/20200707225021.200906-8-peterx@redhat.com
Signed-off-by: Linus Torvalds

mm: do page fault accounting in handle_mm_fault

2020-08-12T17:58:02+00:00

Patch series "mm: Page fault accounting cleanups", v5.

This is v5 of the pf accounting cleanup series.  It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit 4064b9827063 ("mm: allow
VM_FAULT_RETRY for multiple times"):

  https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/

What this series did:

  - Correct page fault accounting: we do accounting for a page fault
    (no matter whether it's from #PF handling, or gup, or anything else)
    only with the one that completed the fault.  For example, page fault
    retries should not be counted in page fault counters.  Same to the
    perf events.

  - Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf
    event is used in an adhoc way across different archs.

    Case (1): for many archs it's done at the entry of a page fault
    handler, so that it will also cover e.g.  errornous faults.

    Case (2): for some other archs, it is only accounted when the page
    fault is resolved successfully.

    Case (3): there're still quite some archs that have not enabled
    this perf event.

    Since this series will touch merely all the archs, we unify this
    perf event to always follow case (1), which is the one that makes most
    sense.  And since we moved the accounting into handle_mm_fault, the
    other two MAJ/MIN perf events are well taken care of naturally.

  - Unify definition of "major faults": the definition of "major
    fault" is slightly changed when used in accounting (not
    VM_FAULT_MAJOR).  More information in patch 1.

  - Always account the page fault onto the one that triggered the page
    fault.  This does not matter much for #PF handlings, but mostly for
    gup.  More information on this in patch 25.

Patchset layout:

Patch 1:     Introduced the accounting in handle_mm_fault(), not enabled.
Patch 2-23:  Enable the new accounting for arch #PF handlers one by one.
Patch 24:    Enable the new accounting for the rest outliers (gup, iommu, etc.)
Patch 25:    Cleanup GUP task_struct pointer since it's not needed any more

This patch (of 25):

This is a preparation patch to move page fault accountings into the
general code in handle_mm_fault().  This includes both the per task
flt_maj/flt_min counters, and the major/minor page fault perf events.  To
do this, the pt_regs pointer is passed into handle_mm_fault().

PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault
handlers.

So far, all the pt_regs pointer that passed into handle_mm_fault() is
NULL, which means this patch should have no intented functional change.

Suggested-by: Linus Torvalds 
Signed-off-by: Peter Xu 
Signed-off-by: Andrew Morton 
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Christian Borntraeger 
Cc: Chris Zankel 
Cc: Dave Hansen 
Cc: David S. Miller 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Greentime Hu 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: H. Peter Anvin 
Cc: Ingo Molnar 
Cc: Ivan Kokshaysky 
Cc: James E.J. Bottomley 
Cc: John Hubbard 
Cc: Jonas Bonn 
Cc: Ley Foon Tan 
Cc: "Luck, Tony" 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Nick Hu 
Cc: Palmer Dabbelt 
Cc: Paul Mackerras 
Cc: Paul Walmsley 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Richard Henderson 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Stefan Kristiansson 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Vasily Gorbik 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com
Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com
Signed-off-by: Linus Torvalds

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14+00:00

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Reviewed-by: Daniel Jordan 
Reviewed-by: Laurent Dufour 
Reviewed-by: Vlastimil Babka 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: John Hubbard 
Cc: Liam Howlett 
Cc: Matthew Wilcox 
Cc: Peter Zijlstra 
Cc: Ying Han 
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

2020-06-09T16:39:13+00:00

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes  to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include 
in the files that include .

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include ") ; do
		sed -i -e '/include / d' $f
	done

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matthew Wilcox 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Mike Rapoport 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vincent Chen 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: free_area_init: use maximal zone PFNs rather than zone sizes

2020-06-04T03:09:43+00:00

Currently, architectures that use free_area_init() to initialize memory
map and node and zone structures need to calculate zone and hole sizes.
We can use free_area_init_nodes() instead and let it detect the zone
boundaries while the architectures will only have to supply the possible
limits for the zones.

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Tested-by: Hoan Tran 	[arm64]
Reviewed-by: Baoquan He 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Ungerer 
Cc: Guan Xuetao 
Cc: Guo Ren 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Nick Hu 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200412194859.12663-5-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: allow VM_FAULT_RETRY for multiple times

2020-04-02T16:35:30+00:00

The idea comes from a discussion between Linus and Andrea [1].

Before this patch we only allow a page fault to retry once.  We achieved
this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing
handle_mm_fault() the second time.  This was majorly used to avoid
unexpected starvation of the system by looping over forever to handle the
page fault on a single page.  However that should hardly happen, and after
all for each code path to return a VM_FAULT_RETRY we'll first wait for a
condition (during which time we should possibly yield the cpu) to happen
before VM_FAULT_RETRY is really returned.

This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY
flag when we receive VM_FAULT_RETRY.  It means that the page fault handler
now can retry the page fault for multiple times if necessary without the
need to generate another page fault event.  Meanwhile we still keep the
FAULT_FLAG_TRIED flag so page fault handler can still identify whether a
page fault is the first attempt or not.

Then we'll have these combinations of fault flags (only considering
ALLOW_RETRY flag and TRIED flag):

  - ALLOW_RETRY and !TRIED:  this means the page fault allows to
                             retry, and this is the first try

  - ALLOW_RETRY and TRIED:   this means the page fault allows to
                             retry, and this is not the first try

  - !ALLOW_RETRY and !TRIED: this means the page fault does not allow
                             to retry at all

  - !ALLOW_RETRY and TRIED:  this is forbidden and should never be used

In existing code we have multiple places that has taken special care of
the first condition above by checking against (fault_flags &
FAULT_FLAG_ALLOW_RETRY).  This patch introduces a simple helper to detect
the first retry of a page fault by checking against both (fault_flags &
FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now
even the 2nd try will have the ALLOW_RETRY set, then use that helper in
all existing special paths.  One example is in __lock_page_or_retry(), now
we'll drop the mmap_sem only in the first attempt of page fault and we'll
keep it in follow up retries, so old locking behavior will be retained.

This will be a nice enhancement for current code [2] at the same time a
supporting material for the future userfaultfd-writeprotect work, since in
that work there will always be an explicit userfault writeprotect retry
for protected pages, and if that cannot resolve the page fault (e.g., when
userfaultfd-writeprotect is used in conjunction with swapped pages) then
we'll possibly need a 3rd retry of the page fault.  It might also benefit
other potential users who will have similar requirement like userfault
write-protection.

GUP code is not touched yet and will be covered in follow up patch.

Please read the thread below for more information.

[1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/
[2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/

Suggested-by: Linus Torvalds 
Suggested-by: Andrea Arcangeli 
Signed-off-by: Peter Xu 
Signed-off-by: Andrew Morton 
Tested-by: Brian Geffon 
Cc: Bobby Powers 
Cc: David Hildenbrand 
Cc: Denis Plotnikov 
Cc: "Dr . David Alan Gilbert" 
Cc: Hugh Dickins 
Cc: Jerome Glisse 
Cc: Johannes Weiner 
Cc: "Kirill A . Shutemov" 
Cc: Martin Cracauer 
Cc: Marty McFadden 
Cc: Matthew Wilcox 
Cc: Maya Gokhale 
Cc: Mel Gorman 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Cc: Pavel Emelyanov 
Link: http://lkml.kernel.org/r/20200220160246.9790-1-peterx@redhat.com
Signed-off-by: Linus Torvalds

mm: introduce FAULT_FLAG_DEFAULT

2020-04-02T16:35:29+00:00

Although there're tons of arch-specific page fault handlers, most of them
are still sharing the same initial value of the page fault flags.  Say,
merely all of the page fault handlers would allow the fault to be retried,
and they also allow the fault to respond to SIGKILL.

Let's define a default value for the fault flags to replace those initial
page fault flags that were copied over.  With this, it'll be far easier to
introduce new fault flag that can be used by all the architectures instead
of touching all the archs.

Signed-off-by: Peter Xu 
Signed-off-by: Andrew Morton 
Tested-by: Brian Geffon 
Reviewed-by: David Hildenbrand 
Cc: Andrea Arcangeli 
Cc: Bobby Powers 
Cc: Denis Plotnikov 
Cc: "Dr . David Alan Gilbert" 
Cc: Hugh Dickins 
Cc: Jerome Glisse 
Cc: Johannes Weiner 
Cc: "Kirill A . Shutemov" 
Cc: Martin Cracauer 
Cc: Marty McFadden 
Cc: Matthew Wilcox 
Cc: Maya Gokhale 
Cc: Mel Gorman 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Cc: Pavel Emelyanov 
Link: http://lkml.kernel.org/r/20200220160238.9694-1-peterx@redhat.com
Signed-off-by: Linus Torvalds

mm: introduce fault_signal_pending()

2020-04-02T16:35:29+00:00

For most architectures, we've got a quick path to detect fatal signal
after a handle_mm_fault().  Introduce a helper for that quick path.

It cleans the current codes a bit so we don't need to duplicate the same
check across archs.  More importantly, this will be an unified place that
we handle the signal immediately right after an interrupted page fault, so
it'll be much easier for us if we want to change the behavior of handling
signals later on for all the archs.

Note that currently only part of the archs are using this new helper,
because some archs have their own way to handle signals.  In the follow up
patches, we'll try to apply this helper to all the rest of archs.

Another note is that the "regs" parameter in the new helper is not used
yet.  It'll be used very soon.  Now we kept it in this patch only to avoid
touching all the archs again in the follow up patches.

[peterx@redhat.com: fix sparse warnings]
  Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1
Signed-off-by: Peter Xu 
Signed-off-by: Andrew Morton 
Tested-by: Brian Geffon 
Cc: Andrea Arcangeli 
Cc: Bobby Powers 
Cc: David Hildenbrand 
Cc: Denis Plotnikov 
Cc: "Dr . David Alan Gilbert" 
Cc: Hugh Dickins 
Cc: Jerome Glisse 
Cc: Johannes Weiner 
Cc: "Kirill A . Shutemov" 
Cc: Martin Cracauer 
Cc: Marty McFadden 
Cc: Matthew Wilcox 
Cc: Maya Gokhale 
Cc: Mel Gorman 
Cc: Mike Kravetz 
Cc: Mike Rapoport 
Cc: Pavel Emelyanov 
Link: http://lkml.kernel.org/r/20200220155353.8676-4-peterx@redhat.com
Signed-off-by: Linus Torvalds

hexagon: remove __iounmap

2019-11-11T20:18:19+00:00

No need to indirect iounmap for hexagon.

Signed-off-by: Christoph Hellwig