Commit Graph

795 Commits

Author SHA1 Message Date
Matthew Wilcox (Oracle)
522a0032af Add linux/cacheflush.h
Many architectures do not include asm-generic/cacheflush.h, so turn
the includes on their head and add linux/cacheflush.h which includes
asm/cacheflush.h.

Move the flush_dcache_folio() declaration from asm-generic/cacheflush.h
to linux/cacheflush.h and change linux/highmem.h to include
linux/cacheflush.h instead of asm/cacheflush.h so that all necessary
places will see flush_dcache_folio().

More functions should have their default implementations moved in the
future, but those are for follow-on patches.  This fixes csky, sparc and
sparc64 which were missed in the commit which added flush_dcache_folio().

Fixes: 08b0b0059b ("mm: Add flush_dcache_folio()")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-11-17 10:36:15 -05:00
Linus Torvalds
e8f023caee Merge tag 'asm-generic-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic cleanup from Arnd Bergmann:
 "This is a single cleanup from Peter Collingbourne, removing some dead
  code"

* tag 'asm-generic-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  arch: remove unused function syscall_set_arguments()
2021-11-10 11:22:03 -08:00
Linus Torvalds
00f178e150 Merge tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa
Pull xtensa updates from Max Filippov:

 - add support for xtensa cores without windowed registers option

* tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: move section symbols to asm/sections.h
  xtensa: remove unused variable wmask
  xtensa: only build windowed register support code when needed
  xtensa: use register window specific opcodes only when present
  xtensa: implement call0 ABI support in assembly
  xtensa: definitions for call0 ABI
  xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
  xtensa: don't use a12 in strncpy_user
  xtensa: use a14 instead of a15 in inline assembly
  xtensa: move _SimulateUserKernelVectorException out of WindowVectors
2021-11-06 14:54:03 -07:00
Linus Torvalds
9a7e0a90a4 Merge tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Thomas Gleixner:

 - Revert the printk format based wchan() symbol resolution as it can
   leak the raw value in case that the symbol is not resolvable.

 - Make wchan() more robust and work with all kind of unwinders by
   enforcing that the task stays blocked while unwinding is in progress.

 - Prevent sched_fork() from accessing an invalid sched_task_group

 - Improve asymmetric packing logic

 - Extend scheduler statistics to RT and DL scheduling classes and add
   statistics for bandwith burst to the SCHED_FAIR class.

 - Properly account SCHED_IDLE entities

 - Prevent a potential deadlock when initial priority is assigned to a
   newly created kthread. A recent change to plug a race between cpuset
   and __sched_setscheduler() introduced a new lock dependency which is
   now triggered. Break the lock dependency chain by moving the priority
   assignment to the thread function.

 - Fix the idle time reporting in /proc/uptime for NOHZ enabled systems.

 - Improve idle balancing in general and especially for NOHZ enabled
   systems.

 - Provide proper interfaces for live patching so it does not have to
   fiddle with scheduler internals.

 - Add cluster aware scheduling support.

 - A small set of tweaks for RT (irqwork, wait_task_inactive(), various
   scheduler options and delaying mmdrop)

 - The usual small tweaks and improvements all over the place

* tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
  sched/fair: Cleanup newidle_balance
  sched/fair: Remove sysctl_sched_migration_cost condition
  sched/fair: Wait before decaying max_newidle_lb_cost
  sched/fair: Skip update_blocked_averages if we are defering load balance
  sched/fair: Account update_blocked_averages in newidle_balance cost
  x86: Fix __get_wchan() for !STACKTRACE
  sched,x86: Fix L2 cache mask
  sched/core: Remove rq_relock()
  sched: Improve wake_up_all_idle_cpus() take #2
  irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
  irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT
  irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.
  sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ
  sched: Add cluster scheduler level for x86
  sched: Add cluster scheduler level in core and related Kconfig for ARM64
  topology: Represent clusters of CPUs within a die
  sched: Disable -Wunused-but-set-variable
  sched: Add wrapper for get_wchan() to keep task blocked
  x86: Fix get_wchan() to support the ORC unwinder
  proc: Use task_is_running() for wchan in /proc/$pid/stat
  ...
2021-11-01 13:48:52 -07:00
Linus Torvalds
49f8275c7d Merge tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache
Pull memory folios from Matthew Wilcox:
 "Add memory folios, a new type to represent either order-0 pages or the
  head page of a compound page. This should be enough infrastructure to
  support filesystems converting from pages to folios.

  The point of all this churn is to allow filesystems and the page cache
  to manage memory in larger chunks than PAGE_SIZE. The original plan
  was to use compound pages like THP does, but I ran into problems with
  some functions expecting only a head page while others expect the
  precise page containing a particular byte.

  The folio type allows a function to declare that it's expecting only a
  head page. Almost incidentally, this allows us to remove various calls
  to VM_BUG_ON(PageTail(page)) and compound_head().

  This converts just parts of the core MM and the page cache. For 5.17,
  we intend to convert various filesystems (XFS and AFS are ready; other
  filesystems may make it) and also convert more of the MM and page
  cache to folios. For 5.18, multi-page folios should be ready.

  The multi-page folios offer some improvement to some workloads. The
  80% win is real, but appears to be an artificial benchmark (postgres
  startup, which isn't a serious workload). Real workloads (eg building
  the kernel, running postgres in a steady state, etc) seem to benefit
  between 0-10%. I haven't heard of any performance losses as a result
  of this series. Nobody has done any serious performance tuning; I
  imagine that tweaking the readahead algorithm could provide some more
  interesting wins. There are also other places where we could choose to
  create large folios and currently do not, such as writes that are
  larger than PAGE_SIZE.

  I'd like to thank all my reviewers who've offered review/ack tags:
  Christoph Hellwig, David Howells, Jan Kara, Jeff Layton, Johannes
  Weiner, Kirill A. Shutemov, Michal Hocko, Mike Rapoport, Vlastimil
  Babka, William Kucharski, Yu Zhao and Zi Yan.

  I'd also like to thank those who gave feedback I incorporated but
  haven't offered up review tags for this part of the series: Nick
  Piggin, Mel Gorman, Ming Lei, Darrick Wong, Ted Ts'o, John Hubbard,
  Hugh Dickins, and probably a few others who I forget"

* tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache: (90 commits)
  mm/writeback: Add folio_write_one
  mm/filemap: Add FGP_STABLE
  mm/filemap: Add filemap_get_folio
  mm/filemap: Convert mapping_get_entry to return a folio
  mm/filemap: Add filemap_add_folio()
  mm/filemap: Add filemap_alloc_folio
  mm/page_alloc: Add folio allocation functions
  mm/lru: Add folio_add_lru()
  mm/lru: Convert __pagevec_lru_add_fn to take a folio
  mm: Add folio_evictable()
  mm/workingset: Convert workingset_refault() to take a folio
  mm/filemap: Add readahead_folio()
  mm/filemap: Add folio_mkwrite_check_truncate()
  mm/filemap: Add i_blocks_per_folio()
  mm/writeback: Add folio_redirty_for_writepage()
  mm/writeback: Add folio_account_redirty()
  mm/writeback: Add folio_clear_dirty_for_io()
  mm/writeback: Add folio_cancel_dirty()
  mm/writeback: Add folio_account_cleaned()
  mm/writeback: Add filemap_dirty_folio()
  ...
2021-11-01 08:47:59 -07:00
Max Filippov
bd47cdb789 xtensa: move section symbols to asm/sections.h
Introduce asm/sections.h and move section declarations to this header
from setup.c. Assign section symbols char array type uniformly and drop
address operator from section symbol references in code.
Sort headers in setup.c while at it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-10-18 22:19:35 -07:00
Max Filippov
da0a4e5c8f xtensa: only build windowed register support code when needed
There's no need in window overflow/underflow/alloca exception handlers
or window spill code when neither kernel nor userspace support windowed
registers. Don't build or link it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-10-18 22:19:35 -07:00
Max Filippov
5cce39b6aa xtensa: definitions for call0 ABI
Add assembly macros for calls, call arguments, preserved registers,
function entry and return for windowed and call0 ABIs.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-10-18 22:19:34 -07:00
Max Filippov
eda8dd1224 xtensa: use a14 instead of a15 in inline assembly
a15 is a frame pointer in the call0 xtensa ABI, don't use it explicitly
in the inline assembly. Use a14 instead, as it has the same properties
as a15 w.r.t. window overflow.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-10-18 22:19:34 -07:00
Matthew Wilcox (Oracle)
08b0b0059b mm: Add flush_dcache_folio()
This is a default implementation which calls flush_dcache_page() on
each page in the folio.  If architectures can do better, they should
implement their own version of it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-10-18 07:49:36 -04:00
Kees Cook
42a20f86dc sched: Add wrapper for get_wchan() to keep task blocked
Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
2021-10-15 11:25:14 +02:00
Randy Dunlap
d67ed2510d xtensa: use CONFIG_USE_OF instead of CONFIG_OF
CONFIG_OF can be set by a randconfig or by a user -- without setting the
early flattree option (OF_EARLY_FLATTREE).  This causes build errors.
However, if randconfig or a user sets USE_OF in the Xtensa config,
the right kconfig symbols are set to fix the build.

Fixes these build errors:

../arch/xtensa/kernel/setup.c:67:19: error: ‘__dtb_start’ undeclared here (not in a function); did you mean ‘dtb_start’?
   67 | void *dtb_start = __dtb_start;
      |                   ^~~~~~~~~~~
../arch/xtensa/kernel/setup.c: In function 'xtensa_dt_io_area':
../arch/xtensa/kernel/setup.c:201:14: error: implicit declaration of function 'of_flat_dt_is_compatible'; did you mean 'of_machine_is_compatible'? [-Werror=implicit-function-declaration]
  201 |         if (!of_flat_dt_is_compatible(node, "simple-bus"))
../arch/xtensa/kernel/setup.c:204:18: error: implicit declaration of function 'of_get_flat_dt_prop' [-Werror=implicit-function-declaration]
  204 |         ranges = of_get_flat_dt_prop(node, "ranges", &len);
../arch/xtensa/kernel/setup.c:204:16: error: assignment to 'const __be32 *' {aka 'const unsigned int *'} from 'int' makes pointer from integer without a cast [-Werror=int-conversion]
  204 |         ranges = of_get_flat_dt_prop(node, "ranges", &len);
      |                ^
../arch/xtensa/kernel/setup.c: In function 'early_init_devtree':
../arch/xtensa/kernel/setup.c:228:9: error: implicit declaration of function 'early_init_dt_scan'; did you mean 'early_init_devtree'? [-Werror=implicit-function-declaration]
  228 |         early_init_dt_scan(params);
../arch/xtensa/kernel/setup.c:229:9: error: implicit declaration of function 'of_scan_flat_dt' [-Werror=implicit-function-declaration]
  229 |         of_scan_flat_dt(xtensa_dt_io_area, NULL);

xtensa-elf-ld: arch/xtensa/mm/mmu.o:(.text+0x0): undefined reference to `xtensa_kio_paddr'

Fixes: da844a8177 ("xtensa: add device trees support")
Fixes: 6cb971114f ("xtensa: remap io area defined in device tree")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-09-27 06:08:58 -07:00
Peter Collingbourne
7962c2eddb arch: remove unused function syscall_set_arguments()
This function appears to have been unused since it was first introduced in
commit 828c365cc8 ("tracehook: asm/syscall.h").

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/I8ce04f002903a37c0b6c1d16e9b2a3afa716c097
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-09-14 16:06:20 +02:00
Arnd Bergmann
e6226997ec asm-generic: reverse GENERIC_{STRNCPY_FROM,STRNLEN}_USER symbols
Most architectures do not need a custom implementation, and in most
cases the generic implementation is preferred, so change the polariy
on these Kconfig symbols to require architectures to select them when
they provide their own version.

The new name is CONFIG_ARCH_HAS_{STRNCPY_FROM,STRNLEN}_USER.

The remaining architectures at the moment are: ia64, mips, parisc,
um and xtensa. We should probably convert these as well, but
I was not sure how far to take this series. Thomas Bogendoerfer
had some concerns about converting mips but may still do some
more detailed measurements to see which version is better.

Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-07-30 10:30:21 +02:00
Linus Torvalds
4cad671979 Merge tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm/unaligned.h unification from Arnd Bergmann:
 "Unify asm/unaligned.h around struct helper

  The get_unaligned()/put_unaligned() helpers are traditionally
  architecture specific, with the two main variants being the
  "access-ok.h" version that assumes unaligned pointer accesses always
  work on a particular architecture, and the "le-struct.h" version that
  casts the data to a byte aligned type before dereferencing, for
  architectures that cannot always do unaligned accesses in hardware.

  Based on the discussion linked below, it appears that the access-ok
  version is not realiable on any architecture, but the struct version
  probably has no downsides. This series changes the code to use the
  same implementation on all architectures, addressing the few
  exceptions separately"

Link: https://lore.kernel.org/lkml/75d07691-1e4f-741f-9852-38c0b4f520bc@synopsys.com/
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363
Link: https://lore.kernel.org/lkml/20210507220813.365382-14-arnd@kernel.org/
Link: git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git unaligned-rework-v2
Link: https://lore.kernel.org/lkml/CAHk-=whGObOKruA_bU3aPGZfoDqZM1_9wBkwREp0H0FgR-90uQ@mail.gmail.com/

* tag 'asm-generic-unaligned-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: simplify asm/unaligned.h
  asm-generic: uaccess: 1-byte access is always aligned
  netpoll: avoid put_unaligned() on single character
  mwifiex: re-fix for unaligned accesses
  apparmor: use get_unaligned() only for multi-byte words
  partitions: msdos: fix one-byte get_unaligned()
  asm-generic: unaligned always use struct helpers
  asm-generic: unaligned: remove byteshift helpers
  powerpc: use linux/unaligned/le_struct.h on LE power7
  m68k: select CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  sh: remove unaligned access for sh4a
  openrisc: always use unaligned-struct header
  asm-generic: use asm-generic/unaligned.h for most architectures
2021-07-02 12:43:40 -07:00
Linus Torvalds
71bd934101 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "190 patches.

  Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
  vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
  migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
  zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
  core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
  signals, exec, kcov, selftests, compress/decompress, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  ipc/util.c: use binary search for max_idx
  ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
  ipc: use kmalloc for msg_queue and shmid_kernel
  ipc sem: use kvmalloc for sem_undo allocation
  lib/decompressors: remove set but not used variabled 'level'
  selftests/vm/pkeys: exercise x86 XSAVE init state
  selftests/vm/pkeys: refill shadow register after implicit kernel write
  selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
  kcov: add __no_sanitize_coverage to fix noinstr for all architectures
  exec: remove checks in __register_bimfmt()
  x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
  hfsplus: report create_date to kstat.btime
  hfsplus: remove unnecessary oom message
  nilfs2: remove redundant continue statement in a while-loop
  kprobes: remove duplicated strong free_insn_page in x86 and s390
  init: print out unknown kernel parameters
  checkpatch: do not complain about positive return values starting with EPOLL
  checkpatch: improve the indented label test
  checkpatch: scripts/spdxcheck.py now requires python3
  ...
2021-07-02 12:08:10 -07:00
Anshuman Khandual
1c2f7d14d8 mm/thp: define default pmd_pgtable()
Currently most platforms define pmd_pgtable() as pmd_page() duplicating
the same code all over.  Instead just define a default value i.e
pmd_page() for pmd_pgtable() and let platforms override when required via
<asm/pgtable.h>.  All the existing platform that override pmd_pgtable()
have been moved into their respective <asm/pgtable.h> header in order to
precede before the new generic definition.  This makes it much cleaner
with reduced code.

Link: https://lkml.kernel.org/r/1623646133-20306-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Anshuman Khandual
fac7757e1f mm: define default value for FIRST_USER_ADDRESS
Currently most platforms define FIRST_USER_ADDRESS as 0UL duplication the
same code all over.  Instead just define a generic default value (i.e 0UL)
for FIRST_USER_ADDRESS and let the platforms override when required.  This
makes it much cleaner with reduced code.

The default FIRST_USER_ADDRESS here would be skipped in <linux/pgtable.h>
when the given platform overrides its value via <asm/pgtable.h>.

Link: https://lkml.kernel.org/r/1620615725-24623-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
David Hildenbrand
4ca9b3859d mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables
I. Background: Sparse Memory Mappings

When we manage sparse memory mappings dynamically in user space - also
sometimes involving MAP_NORESERVE - we want to dynamically populate/
discard memory inside such a sparse memory region.  Example users are
hypervisors (especially implementing memory ballooning or similar
technologies like virtio-mem) and memory allocators.  In addition, we want
to fail in a nice way (instead of generating SIGBUS) if populating does
not succeed because we are out of backend memory (which can happen easily
with file-based mappings, especially tmpfs and hugetlbfs).

While MADV_DONTNEED, MADV_REMOVE and FALLOC_FL_PUNCH_HOLE allow for
reliably discarding memory for most mapping types, there is no generic
approach to populate page tables and preallocate memory.

Although mmap() supports MAP_POPULATE, it is not applicable to the concept
of sparse memory mappings, where we want to populate/discard dynamically
and avoid expensive/problematic remappings.  In addition, we never
actually report errors during the final populate phase - it is best-effort
only.

fallocate() can be used to preallocate file-based memory and fail in a
safe way.  However, it cannot really be used for any private mappings on
anonymous files via memfd due to COW semantics.  In addition, fallocate()
does not actually populate page tables, so we still always get pagefaults
on first access - which is sometimes undesired (i.e., real-time workloads)
and requires real prefaulting of page tables, not just a preallocation of
backend storage.  There might be interesting use cases for sparse memory
regions along with mlockall(MCL_ONFAULT) which fallocate() cannot satisfy
as it does not prefault page tables.

II. On preallcoation/prefaulting from user space

Because we don't have a proper interface, what applications (like QEMU and
databases) end up doing is touching (i.e., reading+writing one byte to not
overwrite existing data) all individual pages.

However, that approach
1) Can result in wear on storage backing, because we end up reading/writing
   each page; this is especially a problem for dax/pmem.
2) Can result in mmap_sem contention when prefaulting via multiple
   threads.
3) Requires expensive signal handling, especially to catch SIGBUS in case
   of hugetlbfs/shmem/file-backed memory. For example, this is
   problematic in hypervisors like QEMU where SIGBUS handlers might already
   be used by other subsystems concurrently to e.g, handle hardware errors.
   "Simply" doing preallocation concurrently from other thread is not that
   easy.

III. On MADV_WILLNEED

Extending MADV_WILLNEED is not an option because
1. It would change the semantics: "Expect access in the near future." and
   "might be a good idea to read some pages" vs. "Definitely populate/
   preallocate all memory and definitely fail on errors.".
2. Existing users (like virtio-balloon in QEMU when deflating the balloon)
   don't want populate/prealloc semantics. They treat this rather as a hint
   to give a little performance boost without too much overhead - and don't
   expect that a lot of memory might get consumed or a lot of time
   might be spent.

IV. MADV_POPULATE_READ and MADV_POPULATE_WRITE

Let's introduce MADV_POPULATE_READ and MADV_POPULATE_WRITE, inspired by
MAP_POPULATE, with the following semantics:
1. MADV_POPULATE_READ can be used to prefault page tables just like
   manually reading each individual page. This will not break any COW
   mappings. The shared zero page might get mapped and no backend storage
   might get preallocated -- allocation might be deferred to
   write-fault time. Especially shared file mappings require an explicit
   fallocate() upfront to actually preallocate backend memory (blocks in
   the file system) in case the file might have holes.
2. If MADV_POPULATE_READ succeeds, all page tables have been populated
   (prefaulted) readable once.
3. MADV_POPULATE_WRITE can be used to preallocate backend memory and
   prefault page tables just like manually writing (or
   reading+writing) each individual page. This will break any COW
   mappings -- e.g., the shared zeropage is never populated.
4. If MADV_POPULATE_WRITE succeeds, all page tables have been populated
   (prefaulted) writable once.
5. MADV_POPULATE_READ and MADV_POPULATE_WRITE cannot be applied to special
   mappings marked with VM_PFNMAP and VM_IO. Also, proper access
   permissions (e.g., PROT_READ, PROT_WRITE) are required. If any such
   mapping is encountered, madvise() fails with -EINVAL.
6. If MADV_POPULATE_READ or MADV_POPULATE_WRITE fails, some page tables
   might have been populated.
7. MADV_POPULATE_READ and MADV_POPULATE_WRITE will return -EHWPOISON
   when encountering a HW poisoned page in the range.
8. Similar to MAP_POPULATE, MADV_POPULATE_READ and MADV_POPULATE_WRITE
   cannot protect from the OOM (Out Of Memory) handler killing the
   process.

While the use case for MADV_POPULATE_WRITE is fairly obvious (i.e.,
preallocate memory and prefault page tables for VMs), one issue is that
whenever we prefault pages writable, the pages have to be marked dirty,
because the CPU could dirty them any time.  while not a real problem for
hugetlbfs or dax/pmem, it can be a problem for shared file mappings: each
page will be marked dirty and has to be written back later when evicting.

MADV_POPULATE_READ allows for optimizing this scenario: Pre-read a whole
mapping from backend storage without marking it dirty, such that eviction
won't have to write it back.  As discussed above, shared file mappings
might require an explciit fallocate() upfront to achieve
preallcoation+prepopulation.

Although sparse memory mappings are the primary use case, this will also
be useful for other preallocate/prefault use cases where MAP_POPULATE is
not desired or the semantics of MAP_POPULATE are not sufficient: as one
example, QEMU users can trigger preallocation/prefaulting of guest RAM
after the mapping was created -- and don't want errors to be silently
suppressed.

Looking at the history, MADV_POPULATE was already proposed in 2013 [1],
however, the main motivation back than was performance improvements --
which should also still be the case.

V. Single-threaded performance comparison

I did a short experiment, prefaulting page tables on completely *empty
mappings/files* and repeated the experiment 10 times.  The results
correspond to the shortest execution time.  In general, the performance
benefit for huge pages is negligible with small mappings.

V.1: Private mappings

POPULATE_READ and POPULATE_WRITE is fastest.  Note that
Reading/POPULATE_READ will populate the shared zeropage where applicable
-- which result in short population times.

The fastest way to allocate backend storage (here: swap or huge pages) and
prefault page tables is POPULATE_WRITE.

V.2: Shared mappings

fallocate() is fastest, however, doesn't prefault page tables.
POPULATE_WRITE is faster than simple writes and read/writes.
POPULATE_READ is faster than simple reads.

Without a fd, the fastest way to allocate backend storage and prefault
page tables is POPULATE_WRITE.  With an fd, the fastest way is usually
FALLOCATE+POPULATE_READ or FALLOCATE+POPULATE_WRITE respectively; one
exception are actual files: FALLOCATE+Read is slightly faster than
FALLOCATE+POPULATE_READ.

The fastest way to allocate backend storage prefault page tables is
FALLOCATE+POPULATE_WRITE -- except when dealing with actual files; then,
FALLOCATE+POPULATE_READ is fastest and won't directly mark all pages as
dirty.

v.3: Detailed results

==================================================
2 MiB MAP_PRIVATE:
**************************************************
Anon 4 KiB     : Read                     :     0.119 ms
Anon 4 KiB     : Write                    :     0.222 ms
Anon 4 KiB     : Read/Write               :     0.380 ms
Anon 4 KiB     : POPULATE_READ            :     0.060 ms
Anon 4 KiB     : POPULATE_WRITE           :     0.158 ms
Memfd 4 KiB    : Read                     :     0.034 ms
Memfd 4 KiB    : Write                    :     0.310 ms
Memfd 4 KiB    : Read/Write               :     0.362 ms
Memfd 4 KiB    : POPULATE_READ            :     0.039 ms
Memfd 4 KiB    : POPULATE_WRITE           :     0.229 ms
Memfd 2 MiB    : Read                     :     0.030 ms
Memfd 2 MiB    : Write                    :     0.030 ms
Memfd 2 MiB    : Read/Write               :     0.030 ms
Memfd 2 MiB    : POPULATE_READ            :     0.030 ms
Memfd 2 MiB    : POPULATE_WRITE           :     0.030 ms
tmpfs          : Read                     :     0.033 ms
tmpfs          : Write                    :     0.313 ms
tmpfs          : Read/Write               :     0.406 ms
tmpfs          : POPULATE_READ            :     0.039 ms
tmpfs          : POPULATE_WRITE           :     0.285 ms
file           : Read                     :     0.033 ms
file           : Write                    :     0.351 ms
file           : Read/Write               :     0.408 ms
file           : POPULATE_READ            :     0.039 ms
file           : POPULATE_WRITE           :     0.290 ms
hugetlbfs      : Read                     :     0.030 ms
hugetlbfs      : Write                    :     0.030 ms
hugetlbfs      : Read/Write               :     0.030 ms
hugetlbfs      : POPULATE_READ            :     0.030 ms
hugetlbfs      : POPULATE_WRITE           :     0.030 ms
**************************************************
4096 MiB MAP_PRIVATE:
**************************************************
Anon 4 KiB     : Read                     :   237.940 ms
Anon 4 KiB     : Write                    :   708.409 ms
Anon 4 KiB     : Read/Write               :  1054.041 ms
Anon 4 KiB     : POPULATE_READ            :   124.310 ms
Anon 4 KiB     : POPULATE_WRITE           :   572.582 ms
Memfd 4 KiB    : Read                     :   136.928 ms
Memfd 4 KiB    : Write                    :   963.898 ms
Memfd 4 KiB    : Read/Write               :  1106.561 ms
Memfd 4 KiB    : POPULATE_READ            :    78.450 ms
Memfd 4 KiB    : POPULATE_WRITE           :   805.881 ms
Memfd 2 MiB    : Read                     :   357.116 ms
Memfd 2 MiB    : Write                    :   357.210 ms
Memfd 2 MiB    : Read/Write               :   357.606 ms
Memfd 2 MiB    : POPULATE_READ            :   356.094 ms
Memfd 2 MiB    : POPULATE_WRITE           :   356.937 ms
tmpfs          : Read                     :   137.536 ms
tmpfs          : Write                    :   954.362 ms
tmpfs          : Read/Write               :  1105.954 ms
tmpfs          : POPULATE_READ            :    80.289 ms
tmpfs          : POPULATE_WRITE           :   822.826 ms
file           : Read                     :   137.874 ms
file           : Write                    :   987.025 ms
file           : Read/Write               :  1107.439 ms
file           : POPULATE_READ            :    80.413 ms
file           : POPULATE_WRITE           :   857.622 ms
hugetlbfs      : Read                     :   355.607 ms
hugetlbfs      : Write                    :   355.729 ms
hugetlbfs      : Read/Write               :   356.127 ms
hugetlbfs      : POPULATE_READ            :   354.585 ms
hugetlbfs      : POPULATE_WRITE           :   355.138 ms
**************************************************
2 MiB MAP_SHARED:
**************************************************
Anon 4 KiB     : Read                     :     0.394 ms
Anon 4 KiB     : Write                    :     0.348 ms
Anon 4 KiB     : Read/Write               :     0.400 ms
Anon 4 KiB     : POPULATE_READ            :     0.326 ms
Anon 4 KiB     : POPULATE_WRITE           :     0.273 ms
Anon 2 MiB     : Read                     :     0.030 ms
Anon 2 MiB     : Write                    :     0.030 ms
Anon 2 MiB     : Read/Write               :     0.030 ms
Anon 2 MiB     : POPULATE_READ            :     0.030 ms
Anon 2 MiB     : POPULATE_WRITE           :     0.030 ms
Memfd 4 KiB    : Read                     :     0.412 ms
Memfd 4 KiB    : Write                    :     0.372 ms
Memfd 4 KiB    : Read/Write               :     0.419 ms
Memfd 4 KiB    : POPULATE_READ            :     0.343 ms
Memfd 4 KiB    : POPULATE_WRITE           :     0.288 ms
Memfd 4 KiB    : FALLOCATE                :     0.137 ms
Memfd 4 KiB    : FALLOCATE+Read           :     0.446 ms
Memfd 4 KiB    : FALLOCATE+Write          :     0.330 ms
Memfd 4 KiB    : FALLOCATE+Read/Write     :     0.454 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_READ  :     0.379 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_WRITE :     0.268 ms
Memfd 2 MiB    : Read                     :     0.030 ms
Memfd 2 MiB    : Write                    :     0.030 ms
Memfd 2 MiB    : Read/Write               :     0.030 ms
Memfd 2 MiB    : POPULATE_READ            :     0.030 ms
Memfd 2 MiB    : POPULATE_WRITE           :     0.030 ms
Memfd 2 MiB    : FALLOCATE                :     0.030 ms
Memfd 2 MiB    : FALLOCATE+Read           :     0.031 ms
Memfd 2 MiB    : FALLOCATE+Write          :     0.031 ms
Memfd 2 MiB    : FALLOCATE+Read/Write     :     0.031 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_READ  :     0.030 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_WRITE :     0.030 ms
tmpfs          : Read                     :     0.416 ms
tmpfs          : Write                    :     0.369 ms
tmpfs          : Read/Write               :     0.425 ms
tmpfs          : POPULATE_READ            :     0.346 ms
tmpfs          : POPULATE_WRITE           :     0.295 ms
tmpfs          : FALLOCATE                :     0.139 ms
tmpfs          : FALLOCATE+Read           :     0.447 ms
tmpfs          : FALLOCATE+Write          :     0.333 ms
tmpfs          : FALLOCATE+Read/Write     :     0.454 ms
tmpfs          : FALLOCATE+POPULATE_READ  :     0.380 ms
tmpfs          : FALLOCATE+POPULATE_WRITE :     0.272 ms
file           : Read                     :     0.191 ms
file           : Write                    :     0.511 ms
file           : Read/Write               :     0.524 ms
file           : POPULATE_READ            :     0.196 ms
file           : POPULATE_WRITE           :     0.434 ms
file           : FALLOCATE                :     0.004 ms
file           : FALLOCATE+Read           :     0.197 ms
file           : FALLOCATE+Write          :     0.554 ms
file           : FALLOCATE+Read/Write     :     0.480 ms
file           : FALLOCATE+POPULATE_READ  :     0.201 ms
file           : FALLOCATE+POPULATE_WRITE :     0.381 ms
hugetlbfs      : Read                     :     0.030 ms
hugetlbfs      : Write                    :     0.030 ms
hugetlbfs      : Read/Write               :     0.030 ms
hugetlbfs      : POPULATE_READ            :     0.030 ms
hugetlbfs      : POPULATE_WRITE           :     0.030 ms
hugetlbfs      : FALLOCATE                :     0.030 ms
hugetlbfs      : FALLOCATE+Read           :     0.031 ms
hugetlbfs      : FALLOCATE+Write          :     0.031 ms
hugetlbfs      : FALLOCATE+Read/Write     :     0.030 ms
hugetlbfs      : FALLOCATE+POPULATE_READ  :     0.030 ms
hugetlbfs      : FALLOCATE+POPULATE_WRITE :     0.030 ms
**************************************************
4096 MiB MAP_SHARED:
**************************************************
Anon 4 KiB     : Read                     :  1053.090 ms
Anon 4 KiB     : Write                    :   913.642 ms
Anon 4 KiB     : Read/Write               :  1060.350 ms
Anon 4 KiB     : POPULATE_READ            :   893.691 ms
Anon 4 KiB     : POPULATE_WRITE           :   782.885 ms
Anon 2 MiB     : Read                     :   358.553 ms
Anon 2 MiB     : Write                    :   358.419 ms
Anon 2 MiB     : Read/Write               :   357.992 ms
Anon 2 MiB     : POPULATE_READ            :   357.533 ms
Anon 2 MiB     : POPULATE_WRITE           :   357.808 ms
Memfd 4 KiB    : Read                     :  1078.144 ms
Memfd 4 KiB    : Write                    :   942.036 ms
Memfd 4 KiB    : Read/Write               :  1100.391 ms
Memfd 4 KiB    : POPULATE_READ            :   925.829 ms
Memfd 4 KiB    : POPULATE_WRITE           :   804.394 ms
Memfd 4 KiB    : FALLOCATE                :   304.632 ms
Memfd 4 KiB    : FALLOCATE+Read           :  1163.359 ms
Memfd 4 KiB    : FALLOCATE+Write          :   933.186 ms
Memfd 4 KiB    : FALLOCATE+Read/Write     :  1187.304 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_READ  :  1013.660 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_WRITE :   794.560 ms
Memfd 2 MiB    : Read                     :   358.131 ms
Memfd 2 MiB    : Write                    :   358.099 ms
Memfd 2 MiB    : Read/Write               :   358.250 ms
Memfd 2 MiB    : POPULATE_READ            :   357.563 ms
Memfd 2 MiB    : POPULATE_WRITE           :   357.334 ms
Memfd 2 MiB    : FALLOCATE                :   356.735 ms
Memfd 2 MiB    : FALLOCATE+Read           :   358.152 ms
Memfd 2 MiB    : FALLOCATE+Write          :   358.331 ms
Memfd 2 MiB    : FALLOCATE+Read/Write     :   358.018 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_READ  :   357.286 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_WRITE :   357.523 ms
tmpfs          : Read                     :  1087.265 ms
tmpfs          : Write                    :   950.840 ms
tmpfs          : Read/Write               :  1107.567 ms
tmpfs          : POPULATE_READ            :   922.605 ms
tmpfs          : POPULATE_WRITE           :   810.094 ms
tmpfs          : FALLOCATE                :   306.320 ms
tmpfs          : FALLOCATE+Read           :  1169.796 ms
tmpfs          : FALLOCATE+Write          :   933.730 ms
tmpfs          : FALLOCATE+Read/Write     :  1191.610 ms
tmpfs          : FALLOCATE+POPULATE_READ  :  1020.474 ms
tmpfs          : FALLOCATE+POPULATE_WRITE :   798.945 ms
file           : Read                     :   654.101 ms
file           : Write                    :  1259.142 ms
file           : Read/Write               :  1289.509 ms
file           : POPULATE_READ            :   661.642 ms
file           : POPULATE_WRITE           :  1106.816 ms
file           : FALLOCATE                :     1.864 ms
file           : FALLOCATE+Read           :   656.328 ms
file           : FALLOCATE+Write          :  1153.300 ms
file           : FALLOCATE+Read/Write     :  1180.613 ms
file           : FALLOCATE+POPULATE_READ  :   668.347 ms
file           : FALLOCATE+POPULATE_WRITE :   996.143 ms
hugetlbfs      : Read                     :   357.245 ms
hugetlbfs      : Write                    :   357.413 ms
hugetlbfs      : Read/Write               :   357.120 ms
hugetlbfs      : POPULATE_READ            :   356.321 ms
hugetlbfs      : POPULATE_WRITE           :   356.693 ms
hugetlbfs      : FALLOCATE                :   355.927 ms
hugetlbfs      : FALLOCATE+Read           :   357.074 ms
hugetlbfs      : FALLOCATE+Write          :   357.120 ms
hugetlbfs      : FALLOCATE+Read/Write     :   356.983 ms
hugetlbfs      : FALLOCATE+POPULATE_READ  :   356.413 ms
hugetlbfs      : FALLOCATE+POPULATE_WRITE :   356.266 ms
**************************************************

[1] https://lkml.org/lkml/2013/6/27/698

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/20210419135443.12822-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Linus Torvalds
65090f30ab Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "191 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
  slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
  mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
  pagealloc, and memory-failure)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
  mm,hwpoison: make get_hwpoison_page() call get_any_page()
  mm,hwpoison: send SIGBUS with error virutal address
  mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
  mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
  mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
  mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
  docs: remove description of DISCONTIGMEM
  arch, mm: remove stale mentions of DISCONIGMEM
  mm: remove CONFIG_DISCONTIGMEM
  m68k: remove support for DISCONTIGMEM
  arc: remove support for DISCONTIGMEM
  arc: update comment about HIGHMEM implementation
  alpha: remove DISCONTIGMEM and NUMA
  mm/page_alloc: move free_the_page
  mm/page_alloc: fix counting of managed_pages
  mm/page_alloc: improve memmap_pages dbg msg
  mm: drop SECTION_SHIFT in code comments
  mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
  mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
  mm/page_alloc: scale the number of pages that are batch freed
  ...
2021-06-29 17:29:11 -07:00
Mike Rapoport
d3c251ab95 arch, mm: remove stale mentions of DISCONIGMEM
There are several places that mention DISCONIGMEM in comments or have
stale code guarded by CONFIG_DISCONTIGMEM.

Remove the dead code and update the comments.

Link: https://lkml.kernel.org/r/20210608091316.3622-7-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Chen Li
5673a60b80 mm: update legacy flush_tlb_* to use vma
1. These tlb flush functions have been using vma instead mm long time
   ago, but there is still some comments use mm as parameter.

2. the actual struct we use is vm_area_struct instead of vma_struct.

3. remove unused flush_kern_tlb_page.

Link: https://lkml.kernel.org/r/87k0oaq311.wl-chenli@uniontech.com
Signed-off-by: Chen Li <chenli@uniontech.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Mark Rutland
b9b12978a8 locking/atomic: xtensa: move to ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).

As a step towards that, this patch migrates xtensa to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-32-mark.rutland@arm.com
2021-05-26 13:20:52 +02:00
Mark Rutland
6988631bdf locking/atomic: cmpxchg: make generic a prefix
The asm-generic implementations of cmpxchg_local() and cmpxchg64_local()
use a `_generic` suffix to distinguish themselves from arch code or
wrappers used elsewhere.

Subsequent patches will add ARCH_ATOMIC support to these
implementations, and will distinguish more functions with a `generic`
portion. To align with how ARCH_ATOMIC uses an `arch_` prefix, it would
be helpful to use a `generic_` prefix rather than a `_generic` suffix.

In preparation for this, this patch renames the existing functions to
make `generic` a prefix rather than a suffix. There should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-12-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Arnd Bergmann
637be9183e asm-generic: use asm-generic/unaligned.h for most architectures
There are several architectures that just duplicate the contents
of asm-generic/unaligned.h, so change those over to use the
file directly, to make future modifications easier.

The exceptions are:

- arm32 sets HAVE_EFFICIENT_UNALIGNED_ACCESS, but wants the
  unaligned-struct version

- ppc64le disables HAVE_EFFICIENT_UNALIGNED_ACCESS but includes
  the access-ok version

- most m68k also uses the access-ok version without setting
  HAVE_EFFICIENT_UNALIGNED_ACCESS.

- sh4a has a custom inline asm version

- openrisc is the only one using the memmove version that
  generally leads to worse code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-05-10 17:43:15 +02:00