In the pmu-events directory for JSON file definitions use the
official machine name IBM z15 instead of machine type number
8561. This is consistent with previous machines.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20190927081147.18345-2-tmricht@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add s390 transaction counter definition for machine 8561. This is the
same file as for the predecessor machine.

Fixes: 6e67d77d ("perf vendor events s390: Add JSON files for machine type 8561")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20190927081147.18345-1-tmricht@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The 'test_dir' variable is assigned to the 'release' array which is
out-of-scope 3 lines later.

Extend the scope of the 'release' array so that an out-of-scope array
isn't accessed.

Bug detected by clang's address sanitizer.

Fixes: 07bc5c69 ("perf tools: Make fetch_kernel_version() publicly available")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/20190926220018.25402-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes in:

  200824f5 ("KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs")
  4a53d99d ("KVM: VMX: Introduce exit reason for receiving INIT signal on guest-mode")
  7396d337 ("KVM: x86: Return to userspace with internal error on unexpected exit reason")
  92f35b75 ("KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINE")

None of them trigger any changes in tooling, this time this is just to silence
these perf build warnings:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h
  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/vmx.h' differs from latest version at 'arch/x86/include/uapi/asm/vmx.h'
  diff -u tools/arch/x86/include/uapi/asm/vmx.h arch/x86/include/uapi/asm/vmx.h
  Warning: Kernel ABI header at 'tools/arch/s390/include/uapi/asm/kvm.h' differs from latest version at 'arch/s390/include/uapi/asm/kvm.h'
  diff -u tools/arch/s390/include/uapi/asm/kvm.h arch/s390/include/uapi/asm/kvm.h
  Warning: Kernel ABI header at 'tools/arch/arm/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm/include/uapi/asm/kvm.h arch/arm/include/uapi/asm/kvm.h
  Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm64/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Huth <thuth@redhat.com>
Link: https://lkml.kernel.org/n/tip-akuugvvjxte26kzv23zp5d2z@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes from:

  78a1b96b ("fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctl")
  23c688b5 ("fscrypt: allow unprivileged users to add/remove keys for v2 policies")
  5dae460c ("fscrypt: v2 encryption policy support")
  5a7e2992 ("fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl")
  b1c0ec35 ("fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl")
  22d94f49 ("fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl")
  3b6df59b ("fscrypt: use FSCRYPT_* definitions, not FS_*")
  2336d0de ("fscrypt: use FSCRYPT_ prefix for uapi constants")
  7af0ab0d ("fs, fscrypt: move uapi definitions to new header <linux/fscrypt.h>")

That don't trigger any changes in tooling, as it so far is used only
for:

  $ grep -l 'fs\.h' tools/perf/trace/beauty/*.sh | xargs grep regex=
  tools/perf/trace/beauty/rename_flags.sh:regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+RENAME_([[:alnum:]_]+)[[:space:]]+\(1[[:space:]]*<<[[:space:]]*([[:xdigit:]]+)[[:space:]]*\)[[:space:]]*.*'
  tools/perf/trace/beauty/sync_file_range.sh:regex='^[[:space:]]*#[[:space:]]*define[[:space:]]+SYNC_FILE_RANGE_([[:alnum:]_]+)[[:space:]]+([[:xdigit:]]+)[[:space:]]*.*'
  tools/perf/trace/beauty/usbdevfs_ioctl.sh:regex="^#[[:space:]]*define[[:space:]]+USBDEVFS_(\w+)(\(\w+\))?[[:space:]]+_IO[CWR]{0,2}\([[:space:]]*(_IOC_\w+,[[:space:]]*)?'U'[[:space:]]*,[[:space:]]*([[:digit:]]+).*"
  tools/perf/trace/beauty/usbdevfs_ioctl.sh:regex="^#[[:space:]]*define[[:space:]]+USBDEVFS_(\w+)[[:space:]]+_IO[WR]{0,2}\([[:space:]]*'U'[[:space:]]*,[[:space:]]*([[:digit:]]+).*"
  $

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/fs.h' differs from latest version at 'include/uapi/linux/fs.h'
  diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-44g48exl9br9ba0t64chqb4i@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes from:

  4ed33505 ("USB: usbfs: Add a capability flag for runtime suspend")
  7794f486 ("usbfs: Add ioctls for runtime power management")

This triggers these changes in the kernel sources, automagically
supporting these new ioctls in the 'perf trace' beautifiers.

Soon this will be used in things like filter expressions for tracepoints
in 'perf record', 'perf trace', 'perf top', i.e. filter expressions will
do a lookup to turn things like USBDEVFS_WAIT_FOR_RESUME into _IO('U',
35) before associating the tracepoint expression to tracepoint perf
event.

  $ tools/perf/trace/beauty/usbdevfs_ioctl.sh  > before
  $ cp include/uapi/linux/usbdevice_fs.h tools/include/uapi/linux/usbdevice_fs.h
  $ git diff
  diff --git a/tools/include/uapi/linux/usbdevice_fs.h b/tools/include/uapi/linux/usbdevice_fs.h
  index 78efe870c2b7..cf525cddeb94 100644
  --- a/tools/include/uapi/linux/usbdevice_fs.h
  +++ b/tools/include/uapi/linux/usbdevice_fs.h
  @@ -158,6 +158,7 @@ struct usbdevfs_hub_portinfo {
   #define USBDEVFS_CAP_MMAP                      0x20
   #define USBDEVFS_CAP_DROP_PRIVILEGES           0x40
   #define USBDEVFS_CAP_CONNINFO_EX               0x80
  +#define USBDEVFS_CAP_SUSPEND                   0x100

   /* USBDEVFS_DISCONNECT_CLAIM flags & struct */

  @@ -223,5 +224,8 @@ struct usbdevfs_streams {
    * extending size of the data returned.
    */
   #define USBDEVFS_CONNINFO_EX(len)  _IOC(_IOC_READ, 'U', 32, len)
  +#define USBDEVFS_FORBID_SUSPEND    _IO('U', 33)
  +#define USBDEVFS_ALLOW_SUSPEND     _IO('U', 34)
  +#define USBDEVFS_WAIT_FOR_RESUME   _IO('U', 35)

   #endif /* _UAPI_LINUX_USBDEVICE_FS_H */
  $ tools/perf/trace/beauty/usbdevfs_ioctl.sh  > after
  $ diff -u before after
  --- before	2019-09-27 11:41:50.634867620 -0300
  +++ after	2019-09-27 11:42:07.453102978 -0300
  @@ -24,6 +24,9 @@
   	[30] = "DROP_PRIVILEGES",
   	[31] = "GET_SPEED",
   	[32] = "CONNINFO_EX",
  +	[33] = "FORBID_SUSPEND",
  +	[34] = "ALLOW_SUSPEND",
  +	[35] = "WAIT_FOR_RESUME",
   	[3] = "RESETEP",
   	[4] = "SETINTERFACE",
   	[5] = "SETCONFIGURATION",
  $

This addresses the following perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/usbdevice_fs.h' differs from latest version at 'include/uapi/linux/usbdevice_fs.h'
  diff -u tools/include/uapi/linux/usbdevice_fs.h include/uapi/linux/usbdevice_fs.h

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x1rb109b9nfi7pukota82xhj@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes from:

  1a4e58cc ("mm: introduce MADV_PAGEOUT")
  9c276cc6 ("mm: introduce MADV_COLD")

That result in these changes in the tools:

  $ tools/perf/trace/beauty/madvise_behavior.sh > before
  $ cp include/uapi/asm-generic/mman-common.h tools/include/uapi/asm-generic/mman-common.h
  $ git diff
  diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
  index 63b1f506ea67..c160a5354eb6 100644
  --- a/tools/include/uapi/asm-generic/mman-common.h
  +++ b/tools/include/uapi/asm-generic/mman-common.h
  @@ -67,6 +67,9 @@
   #define MADV_WIPEONFORK 18             /* Zero memory on fork, child only */
   #define MADV_KEEPONFORK 19             /* Undo MADV_WIPEONFORK */

  +#define MADV_COLD      20              /* deactivate these pages */
  +#define MADV_PAGEOUT   21              /* reclaim these pages */
  +
   /* compatibility flags */
   #define MAP_FILE       0

  $ tools/perf/trace/beauty/madvise_behavior.sh > after
  $ diff -u before after
  --- before	2019-09-27 11:29:43.346320100 -0300
  +++ after	2019-09-27 11:30:03.838570439 -0300
  @@ -16,6 +16,8 @@
   	[17] = "DODUMP",
   	[18] = "WIPEONFORK",
   	[19] = "KEEPONFORK",
  +	[20] = "COLD",
  +	[21] = "PAGEOUT",
   	[100] = "HWPOISON",
   	[101] = "SOFT_OFFLINE",
   };
  $

I.e. now when madvise gets those behaviours as args, it will be able to
translate from the number to a human readable string.

This addresses the following perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/mman-common.h' differs from latest version at 'include/uapi/asm-generic/mman-common.h'
  diff -u tools/include/uapi/asm-generic/mman-common.h include/uapi/asm-generic/mman-common.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-n40y6c4sa49p29q6sl8w3ufx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick the change in:

  bf73fc0f ("drm/i915: Show support for accurate sw PMU busyness tracking")

That don't result in any changes in tooling, just silences this perf
build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h'
  diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-o651nt7vpz93tu3nmx4f3xql@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

With this change if a perf_date parameter is provided to asciidoc then
it will override the default date written to the man page metadata.

Without this change, or if the perf_date isn't specified, then the
current date is written to the metadata.

Having this parameter allows the metadata to be constant if builds
happen on different dates.

The name of the parameter is intended to be consistent with the existing
perf_version parameter.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20190921041327.155054-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

An optimized build such as:

  make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-O3

will turn the dereference operation into a ud2 instruction, raising a
SIGILL rather than a SIGSEGV. Use raise(..) for correctness and clarity.

Similar issues were addressed in Numfor Mbiziwo-Tiapo's patch:

  https://lkml.org/lkml/2019/7/8/1234

Committer testing:

Before:

  [root@quaco ~]# perf test hooks
  55: perf hooks                                            : Ok
  [root@quaco ~]# perf test -v hooks
  55: perf hooks                                            :
  --- start ---
  test child forked, pid 17092
  SIGSEGV is observed as expected, try to recover.
  Fatal error (SEGFAULT) in perf hook 'test'
  test child finished with 0
  ---- end ----
  perf hooks: Ok
  [root@quaco ~]#

After:

  [root@quaco ~]# perf test hooks
  55: perf hooks                                            : Ok
  [root@quaco ~]# perf test -v hooks
  55: perf hooks                                            :
  --- start ---
  test child forked, pid 17909
  SIGSEGV is observed as expected, try to recover.
  Fatal error (SEGFAULT) in perf hook 'test'
  test child finished with 0
  ---- end ----
  perf hooks: Ok
  [root@quaco ~]#

Fixes: a074865e ("perf tools: Introduce perf hooks")
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/20190925195924.152834-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Unconditionally defining _FORTIFY_SOURCE can break tools that don't work
with it, such as memory sanitizers:

  https://github.com/google/sanitizers/wiki/AddressSanitizer#faq

Fixes: 4b6ab94e ("perf subcmd: Create subcmd library")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20190925195924.152834-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull timer fix from Ingo Molnar:
 "Fix a timer expiry bug that would cause spurious delay of timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Read jiffies once when forwarding base clk

Pull more perf updates from Ingo Molnar:
 "The only kernel change is comment typo fixes.

  The rest is mostly tooling fixes, but also new vendor event additions
  and updates, a bigger libperf/libtraceevent library and a header files
  reorganization that came in a bit late"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
  perf unwind: Fix libunwind build failure on i386 systems
  perf parser: Remove needless include directives
  perf build: Add detection of java-11-openjdk-devel package
  perf jvmti: Include JVMTI support for s390
  perf vendor events: Remove P8 HW events which are not supported
  perf evlist: Fix access of freed id arrays
  perf stat: Fix free memory access / memory leaks in metrics
  perf tools: Replace needless mmap.h with what is needed, event.h
  perf evsel: Move config terms to a separate header
  perf evlist: Remove unused perf_evlist__fprintf() method
  perf evsel: Introduce evsel_fprintf.h
  perf evsel: Remove need for symbol_conf in evsel_fprintf.c
  perf copyfile: Move copyfile routines to separate files
  libperf: Add perf_evlist__poll() function
  libperf: Add perf_evlist__add_pollfd() function
  libperf: Add perf_evlist__alloc_pollfd() function
  libperf: Add libperf_init() call to the tests
  libperf: Merge libperf_set_print() into libperf_init()
  libperf: Add libperf dependency for tests targets
  libperf: Use sys/types.h to get ssize_t, not unistd.h
  ...

Pull tracing fix from Steven Rostedt:
 "Srikar Dronamraju fixed a bug in the newmulti probe code"

* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Fix same probe event argument matching

Naresh Kamboju reported, that on the i386 build pr_err()
doesn't get defined properly due to header ordering:

  perf-in.o: In function `libunwind__x86_reg_id':
  tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109:
  undefined reference to `pr_err'
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull usercopy fix from Kees Cook:
 "Fix hardened usercopy under CONFIG_DEBUG_VIRTUAL"

* tag 'usercopy-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: Avoid HIGHMEM pfn warning

Merge tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:
 "Fixes to existing tests"

* tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tpm2: install python files
  selftests: livepatch: add missing fragments to config
  selftests: watchdog: cleanup whitespace in usage options
  selftest/ftrace: Fix typo in trigger-snapshot.tc
  selftests: watchdog: Add optional file argument
  selftests/seccomp: fix build on older kernels
  selftests: use "$(MAKE)" instead of "make"

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - Dequeue the request from the receive queue while we're re-encoding
     # v4.20+
   - Fix buffer handling of GSS MIC without slack # 5.1

  Features:
   - Increase xprtrdma maximum transport header and slot table sizes
   - Add support for nfs4_call_sync() calls using a custom
     rpc_task_struct
   - Optimize the default readahead size
   - Enable pNFS filelayout LAYOUTGET on OPEN

  Other bugfixes and cleanups:
   - Fix possible null-pointer dereferences and memory leaks
   - Various NFS over RDMA cleanups
   - Various NFS over RDMA comment updates
   - Don't receive TCP data into a reset request buffer
   - Don't try to parse incomplete RPC messages
   - Fix congestion window race with disconnect
   - Clean up pNFS return-on-close error handling
   - Fixes for NFS4ERR_OLD_STATEID handling"

* tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits)
  pNFS/filelayout: enable LAYOUTGET on OPEN
  NFS: Optimise the default readahead size
  NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU
  NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
  NFSv4: Fix OPEN_DOWNGRADE error handling
  pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid
  NFSv4: Add a helper to increment stateid seqids
  NFSv4: Handle RPC level errors in LAYOUTRETURN
  NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close
  NFSv4: Clean up pNFS return-on-close error handling
  pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors
  NFS: remove unused check for negative dentry
  NFSv3: use nfs_add_or_obtain() to create and reference inodes
  NFS: Refactor nfs_instantiate() for dentry referencing callers
  SUNRPC: Fix congestion window race with disconnect
  SUNRPC: Don't try to parse incomplete RPC messages
  SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic
  SUNRPC: Fix buffer handling of GSS MIC without slack
  SUNRPC: RPC level errors should always set task->tk_rpc_status
  SUNRPC: Don't receive TCP data into a request buffer that has been reset
  ...

When brk was moved for binaries without an interpreter, it should have
been limited to ET_DYN only. In other words, the special case was an
ET_DYN that lacks an INTERP, not just an executable that lacks INTERP.
The bug manifested for giant static executables, where the brk would end
up in the middle of the text area on 32-bit architectures.
Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in>
Fixes: bbdc6076 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull xfs fixes from Darrick Wong:
 "There are a couple of bug fixes and some small code cleanups that came
  in recently:

   - Minor code cleanups

   - Fix a superblock logging error

   - Ensure that collapse range converts the data fork to extents format
     when necessary

   - Revert the ALLOC_USERDATA cleanup because it caused subtle behavior
     regressions"

* tag 'xfs-5.4-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: avoid unused to_mp() function warning
  xfs: log proper length of superblock
  xfs: revert 1baa2800 ("xfs: remove the unused XFS_ALLOC_USERDATA flag")
  xfs: removed unneeded variable
  xfs: convert inode to extent format after extent merge due to shift

Pull jffs2 fix from Al Viro:
 "braino fix for mount API conversion for jffs2"

* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jffs2: Fix mounting under new mount API

Pull more s390 updates from Vasily Gorbik:

 - Fix three kasan findings

 - Add PERF_EVENT_IOC_PERIOD ioctl support

 - Add Crypto Express7S support and extend sysfs attributes for pkey

 - Minor common I/O layer documentation corrections

* tag 's390-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/cio: exclude subchannels with no parent from pseudo check
  s390/cio: avoid calling strlen on null pointer
  s390/topology: avoid firing events before kobjs are created
  s390/cpumf: Remove mixed white space
  s390/cpum_sf: Support ioctl PERF_EVENT_IOC_PERIOD
  s390/zcrypt: CEX7S exploitation support
  s390/cio: fix intparm documentation
  s390/pkey: Add sysfs attributes to emit AES CIPHER key blobs

Pull xen update from Juergen Gross:
 "Only two small patches this time:

   - a small cleanup for swiotlb-xen

   - a fix for PCI initialization for some platforms"

* tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: reserve MCFG areas earlier
  swiotlb-xen: Convert to use macro

Merge more updates from Andrew Morton:

 - almost all of the rest of -mm

 - various other subsystems

Subsystems affected by this patch series:
  memcg, misc, core-kernel, lib, checkpatch, reiserfs, fat, fork,
  cpumask, kexec, uaccess, kconfig, kgdb, bug, ipc, lzo, kasan, madvise,
  cleanups, pagemap

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (77 commits)
  arch/sparc/include/asm/pgtable_64.h: fix build
  mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
  ntfs: remove (un)?likely() from IS_ERR() conditions
  IB/hfi1: remove unlikely() from IS_ERR*() condition
  xfs: remove unlikely() from WARN_ON() condition
  wimax/i2400m: remove unlikely() from WARN*() condition
  fs: remove unlikely() from WARN_ON() condition
  xen/events: remove unlikely() from WARN() condition
  checkpatch: check for nested (un)?likely() calls
  hexagon: drop empty and unused free_initrd_mem
  mm: factor out common parts between MADV_COLD and MADV_PAGEOUT
  mm: introduce MADV_PAGEOUT
  mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM
  mm: introduce MADV_COLD
  mm: untag user pointers in mmap/munmap/mremap/brk
  vfio/type1: untag user pointers in vaddr_get_pfn
  tee/shm: untag user pointers in tee_shm_register
  media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get
  drm/radeon: untag user pointers in radeon_gem_userptr_ioctl
  drm/amdgpu: untag user pointers
  ...

A last-minute fixlet which I'd failed to merge at the appropriate time
had the predictable effect.

Fixes: f672e2c217e2d4b2 ("lib: untag user pointers in strn*_user")
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.comSigned-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"likely(!IS_ERR(x))" is excessive. IS_ERR() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-11-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-8-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-7-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-6-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-5-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN(x))" is excessive. WARN() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-4-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The mounting of jffs2 is broken due to the changes from the new mount API
because it specifies a "source" operation, but then doesn't actually
process it.  But because it specified it, it doesn't return -ENOPARAM and
the caller doesn't process it either and the source gets lost.

Fix this by simply removing the source parameter from jffs2 and letting the
VFS deal with it in the default manner.

To test it, enable CONFIG_MTD_MTDRAM and allow the default size and erase
block size parameters, then try and mount the /dev/mtdblock<N> file that
that creates as jffs2.  No need to initialise it.

Fixes: ec10a24f ("vfs: Convert jffs2 to use the new mount API")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Merge tag 'perf-core-for-mingo-5.5-20190925' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

perf record:

  Stephane Eranian:

  - Fix priv level with branch sampling for paranoid=2, i.e. the kernel checks
    if perf_event_attr_attr.exclude_hv is set in addition to .exclude_kernel,
    so reset both to zero.

  Arnaldo Carvalho de Melo:

  - Don't warn about not being able to read kernel maps (kallsyms, etc) when
    kernel samples aren't being collected.

perf list:

  Kim Phillips:

  - Allow plurals for metric, metricgroup., i.e.:

    $ perf list metrics

    was showing nothing, which is very confusing, make it work like:

    $ perf stat metric

perf stat:

  Andi Kleen:

  - Free memory access/leaks detected via valgrind, related to metrics.

Libraries:

libperf:

  Jiri Olsa:

  - Move more stuff from tools/perf, this time a first stab at moving perf_mmap
    methods.

libtracevent:

  Steven Rostedt (VMware):

  - Round up in tep_print_event() time precision.

  Tzvetomir Stoyanov (VMware):

  - Man pages for event print and related and plugins APIs.

  - Move traceevent plugins in its own subdirectory.

Feature detection:

  Thomas Richter:

  - Add detection of java-11-openjdk-devel package, in addition to the older
    versions supported.

Architecture specific:

S/390:

  Thomas Richter (2):

  - Include JVMTI support for s390

Vendor events:

AMD:

  Kim Phillips:

  - Add L3 cache events for Family 17h.

  - Remove redundant '['.

PowerPC:

  Mamatha Inamdar:

  - Remove P8 HW events which are not supported.

Cleanups:

  Arnaldo Carvalho de Melo:

  - Remove needless headers, add needed ones, move things around to reduce the
    headers dependency tree, speeding up builds by not doing needless compiles
    when unrelated stuff gets changed.

  - Ditch unused code that was dragging headers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

IS_ERR(), IS_ERR_OR_NULL(), IS_ERR_VALUE() and WARN*() already contain
unlikely() optimization internally.  Thus, there is no point in calling
these functions and defines under likely()/unlikely().

This check is based on the coccinelle rule developed by Enrico Weigelt
https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@metux.net/

Link: http://lkml.kernel.org/r/20190829165025.15750-1-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Joe Perches <joe@perches.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Boris Pismenny <borisp@mellanox.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Denis Efremov <efremov@linux.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Sean Paul <sean@poorly.run>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hexagon never reserves or initializes initrd and the only mention of it is
the empty free_initrd_mem() function.

As we have a generic implementation of free_initrd_mem(), there is no need
to define an empty stub for the hexagon implementation and it can be
dropped.

Link: http://lkml.kernel.org/r/1565858133-25852-1-git-send-email-rppt@linux.ibm.comSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.

Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use.  This could reduce workingset
eviction so it ends up increasing performance.

This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly.  The hint can help kernel in deciding which pages to
evict proactively.

A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size.  If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].

- man-page material

MADV_PAGEOUT (since Linux x.x)

Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.

MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.

[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/

[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
  Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default.  It is for preventing to reclaim dirty pages when CMA try to
migrate pages.  Strictly speaking, we don't need it because CMA didn't
allow to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch.  So
this patch makes references's default value to PAGEREF_RECLAIM and rename
force_reclaim with ignore_references to make it more clear.

This is a preparatory work for next patch.

Link: http://lkml.kernel.org/r/20190726023435.214162-3-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7.

- Background

The Android terminology used for forking a new process and starting an app
from scratch is a cold start, while resuming an existing app is a hot
start.  While we continually try to improve the performance of cold
starts, hot starts will always be significantly less power hungry as well
as faster so we are trying to make hot start more likely than cold start.

To increase hot start, Android userspace manages the order that apps
should be killed in a process called ActivityManagerService.
ActivityManagerService tracks every Android app or service that the user
could be interacting with at any time and translates that into a ranked
list for lmkd(low memory killer daemon).  They are likely to be killed by
lmkd if the system has to reclaim memory.  In that sense they are similar
to entries in any other cache.  Those apps are kept alive for
opportunistic performance improvements but those performance improvements
will vary based on the memory requirements of individual workloads.

- Problem

Naturally, cached apps were dominant consumers of memory on the system.
However, they were not significant consumers of swap even though they are
good candidate for swap.  Under investigation, swapping out only begins
once the low zone watermark is hit and kswapd wakes up, but the overall
allocation rate in the system might trip lmkd thresholds and cause a
cached process to be killed(we measured performance swapping out vs.
zapping the memory by killing a process.  Unsurprisingly, zapping is 10x
times faster even though we use zram which is much faster than real
storage) so kill from lmkd will often satisfy the high zone watermark,
resulting in very few pages actually being moved to swap.

- Approach

The approach we chose was to use a new interface to allow userspace to
proactively reclaim entire processes by leveraging platform information.
This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages
that are known to be cold from userspace and to avoid races with lmkd by
reclaiming apps as soon as they entered the cached state.  Additionally,
it could provide many chances for platform to use much information to
optimize memory efficiency.

To achieve the goal, the patchset introduce two new options for madvise.
One is MADV_COLD which will deactivate activated pages and the other is
MADV_PAGEOUT which will reclaim private pages instantly.  These new
options complement MADV_DONTNEED and MADV_FREE by adding non-destructive
ways to gain some free memory space.  MADV_PAGEOUT is similar to
MADV_DONTNEED in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed immediately; MADV_COLD is similar
to MADV_FREE in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed when memory pressure rises.

This patch (of 5):

When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use.  This could reduce
workingset eviction so it ends up increasing performance.

This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future.  The hint can help kernel in deciding which
pages to evict early during memory pressure.

It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves

	active file page -> inactive file LRU
	active anon page -> inacdtive anon LRU

Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault.  Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages.  It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied.  Even, it could give a bonus to make
them be reclaimed on swapless system.  However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost.  Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU.  Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device.  Let's start simpler way without adding
complexity at this moment.  However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.

* man-page material

MADV_COLD (since Linux x.x)

Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies.  In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.

MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.

[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>