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  1. 30 Aug, 2021 4 commits
  3. 27 Aug, 2021 1 commit
  5. 30 Jul, 2021 1 commit
    • Petr Mladek's avatar
      lib/nmi_backtrace: Serialize even messages about idle CPUs · 26d1982f
      Petr Mladek authored 
      The commit 55d6af1d ("lib/nmi_backtrace: explicitly serialize
banner and regs") serialized backtraces from more CPUs using the re-entrant
printk_printk_cpu lock. It was a preparation step for removing the obsolete
nmi_safe buffers.

The single-line messages about idle CPUs were not serialized against other
CPUs and might appear in the middle of backtrace from another CPU,
for example:

[56394.590068] NMI backtrace for cpu 2
[56394.590069] CPU: 2 PID: 444 Comm: systemd-journal Not tainted 5.14.0-rc1-default+ #268
[56394.590071] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
[56394.590072] RIP: 0010:lock_is_held_type+0x0/0x120
[56394.590071] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xb/0x10
[56394.590076] Code: a2 38 ff 0f 0b 8b 44 24 04 eb bd 48 8d ...
[56394.590077] RSP: 0018:ffffab02c07c7e68 EFLAGS: 00000246
[56394.590079] RAX: 0000000000000000 RBX: ffff9a7bc0ec8a40 RCX: ffffffffaab8eb40

It might cause confusion what CPU the following lines belongs to and
whether the backtraces are really serialized.

Prevent the confusion and serialize also the single line message against
other CPUs.

Fixes: 55d6af1d ("lib/nmi_backtrace: explicitly serialize banner and regs")
Reviewed-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Reviewed-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210727080939.27193-1-pmladek@suse.com
      26d1982f
  7. 29 Jul, 2021 3 commits
  9. 26 Jul, 2021 8 commits
  11. 23 Jul, 2021 1 commit
  13. 19 Jul, 2021 5 commits
    • Chris Down's avatar
      printk: index: Add indexing support to dev_printk · ad7d61f1
      Chris Down authored 
      While for most kinds of issues we have counters, tracepoints, or metrics
with a stable interface which can reliably be used to indicate issues,
in order to react to production issues quickly we sometimes need to work
with the interface which most kernel developers naturally use when
developing: printk, and printk-esques like dev_printk.

dev_printk is by far the most likely custom subsystem printk to benefit
from the printk indexing infrastructure, since niche device issues
brought about by production changes, firmware upgrades, and the like are
one of the most common things that we need printk infrastructure's
assistance to monitor.

Often these errors were never expected to practically manifest in
reality, and exhibit in code without extensive (or any) metrics present.
As such, there are typically very few options for issue detection
available to those with large fleets at the time the incident happens,
and we thus benefit strongly from monitoring netconsole in these
instances.

As such, add the infrastructure for dev_printk to be indexed in the
printk index. Even on a minimal kernel config, the coverage of the base
kernel's printk index is significantly improved:

Before:

    [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
    4497 /sys/kernel/debug/printk/index/vmlinux

After:

    [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
    5573 /sys/kernel/debug/printk/index/vmlinux

In terms of implementation, in order to trivially disambiguate them,
dev_printk is now a macro which wraps _dev_printk.
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Tested-by: default avatarPetr Mladek <pmladek@suse.com>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/959c7aed1017cb2c9de922e0a820d397e29c6a5a.1623775748.git.chris@chrisdown.name
      ad7d61f1
    • Chris Down's avatar
      printk: Userspace format indexing support · 33701557
      Chris Down authored 
      We have a number of systems industry-wide that have a subset of their
functionality that works as follows:

1. Receive a message from local kmsg, serial console, or netconsole;
2. Apply a set of rules to classify the message;
3. Do something based on this classification (like scheduling a
   remediation for the machine), rinse, and repeat.

As a couple of examples of places we have this implemented just inside
Facebook, although this isn't a Facebook-specific problem, we have this
inside our netconsole processing (for alarm classification), and as part
of our machine health checking. We use these messages to determine
fairly important metrics around production health, and it's important
that we get them right.

While for some kinds of issues we have counters, tracepoints, or metrics
with a stable interface which can reliably indicate the issue, in order
to react to production issues quickly we need to work with the interface
which most kernel developers naturally use when developing: printk.

Most production issues come from unexpected phenomena, and as such
usually the code in question doesn't have easily usable tracepoints or
other counters available for the specific problem being mitigated. We
have a number of lines of monitoring defence against problems in
production (host metrics, process metrics, service metrics, etc), and
where it's not feasible to reliably monitor at another level, this kind
of pragmatic netconsole monitoring is essential.

As one would expect, monitoring using printk is rather brittle for a
number of reasons -- most notably that the message might disappear
entirely in a new version of the kernel, or that the message may change
in some way that the regex or other classification methods start to
silently fail.

One factor that makes this even harder is that, under normal operation,
many of these messages are never expected to be hit. For example, there
may be a rare hardware bug which one wants to detect if it was to ever
happen again, but its recurrence is not likely or anticipated. This
precludes using something like checking whether the printk in question
was printed somewhere fleetwide recently to determine whether the
message in question is still present or not, since we don't anticipate
that it should be printed anywhere, but still need to monitor for its
future presence in the long-term.

This class of issue has happened on a number of occasions, causing
unhealthy machines with hardware issues to remain in production for
longer than ideal. As a recent example, some monitoring around
blk_update_request fell out of date and caused semi-broken machines to
remain in production for longer than would be desirable.

Searching through the codebase to find the message is also extremely
fragile, because many of the messages are further constructed beyond
their callsite (eg. btrfs_printk and other module-specific wrappers,
each with their own functionality). Even if they aren't, guessing the
format and formulation of the underlying message based on the aesthetics
of the message emitted is not a recipe for success at scale, and our
previous issues with fleetwide machine health checking demonstrate as
much.

This provides a solution to the issue of silently changed or deleted
printks: we record pointers to all printk format strings known at
compile time into a new .printk_index section, both in vmlinux and
modules. At runtime, this can then be iterated by looking at
<debugfs>/printk/index/<module>, which emits the following format, both
readable by humans and able to be parsed by machines:

    $ head -1 vmlinux; shuf -n 5 vmlinux
    # <level[,flags]> filename:line function "format"
    <5> block/blk-settings.c:661 disk_stack_limits "%s: Warning: Device %s is misaligned\n"
    <4> kernel/trace/trace.c:8296 trace_create_file "Could not create tracefs '%s' entry\n"
    <6> arch/x86/kernel/hpet.c:144 _hpet_print_config "hpet: %s(%d):\n"
    <6> init/do_mounts.c:605 prepare_namespace "Waiting for root device %s...\n"
    <6> drivers/acpi/osl.c:1410 acpi_no_auto_serialize_setup "ACPI: auto-serialization disabled\n"

This mitigates the majority of cases where we have a highly-specific
printk which we want to match on, as we can now enumerate and check
whether the format changed or the printk callsite disappeared entirely
in userspace. This allows us to catch changes to printks we monitor
earlier and decide what to do about it before it becomes problematic.

There is no additional runtime cost for printk callers or printk itself,
and the assembly generated is exactly the same.
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Tested-by: default avatarPetr Mladek <pmladek@suse.com>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Jessica Yu <jeyu@kernel.org> # for module.{c,h}
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/e42070983637ac5e384f17fbdbe86d19c7b212a5.1623775748.git.chris@chrisdown.name
      33701557
    • Chris Down's avatar
      printk: Rework parse_prefix into printk_parse_prefix · f3d75cf5
      Chris Down authored 
      parse_prefix is needed externally by later patches, so move it into a
context where it can be used as such. Also give it the printk_ prefix to
reduce the chance of collisions.
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/b22ba314a860e5c7f887958f1eab2649f9bd1d06.1623775748.git.chris@chrisdown.name
      f3d75cf5
    • Chris Down's avatar
      printk: Straighten out log_flags into printk_info_flags · a1ad4b8a
      Chris Down authored 
      In the past, `enum log_flags` was part of `struct log`, hence the name.
`struct log` has since been reworked and now this struct is stored
inside `struct printk_info`. However, the name was never updated, which
is somewhat confusing -- especially since these flags operate at the
record level rather than at the level of an abstract log.

printk_info_flags also joins its other metadata struct friends in
printk_ringbuffer.h.
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/3dd801982f02603e6e3aa4f8bc4f5ebb830a4949.1623775748.git.chris@chrisdown.name
      a1ad4b8a
    • Chris Down's avatar
      string_helpers: Escape double quotes in escape_special · 91027d0a
      Chris Down authored 
      From an abstract point of view, escape_special's counterpart,
unescape_special, already handles the unescaping of blackslashed double
quote sequences.

As a more practical example, printk indexing is an example case where
this is already practically useful. Compare an example with
`ESCAPE_SPECIAL | ESCAPE_SPACE`, with quotes not escaped:

    [root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
    <4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string "%s"\n"

...and the same after this patch:

    [root@ktst ~]# grep drivers/pci/pci-stub.c:69 /sys/kernel/debug/printk/index/vmlinux
    <4> drivers/pci/pci-stub.c:69 pci_stub_init "pci-stub: invalid ID string \"%s\"\n"

One can of course, alternatively, use ESCAPE_APPEND with a quote in
@only, but without this patch quotes are coerced into hex or octal which
can hurt readability quite significantly.

I've checked uses of ESCAPE_SPECIAL and %pE across the codebase, and I'm
pretty confident that this shouldn't affect any stable interfaces.
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/af144c5b75e41ce417386253ba2694456bc04118.1623775748.git.chris@chrisdown.name
      91027d0a
  15. 11 Jul, 2021 11 commits
    • Linus Torvalds's avatar
      Linux 5.14-rc1 · e73f0f0e
      Linus Torvalds authored
      e73f0f0e
    • Hugh Dickins's avatar
      mm/rmap: try_to_migrate() skip zone_device !device_private · 6c855fce
      Hugh Dickins authored 
      I know nothing about zone_device pages and !device_private pages; but if
try_to_migrate_one() will do nothing for them, then it's better that
try_to_migrate() filter them first, than trawl through all their vmas.
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Reviewed-by: default avatarAlistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/lkml/1241d356-8ec9-f47b-a5ec-9b2bf66d242@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6c855fce
    • Hugh Dickins's avatar
      mm/rmap: fix new bug: premature return from page_mlock_one() · 023e1a8d
      Hugh Dickins authored 
      In the unlikely race case that page_mlock_one() finds VM_LOCKED has been
cleared by the time it got page table lock, page_vma_mapped_walk_done()
must be called before returning, either explicitly, or by a final call
to page_vma_mapped_walk() - otherwise the page table remains locked.

Fixes: cd62734c ("mm/rmap: split try_to_munlock from try_to_unmap")
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarAlistair Popple <apopple@nvidia.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/20210711151446.GB4070@xsang-OptiPlex-9020/
Link: https://lore.kernel.org/lkml/f71f8523-cba7-3342-40a7-114abc5d1f51@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      023e1a8d
    • Hugh Dickins's avatar
      mm/rmap: fix old bug: munlocking THP missed other mlocks · d9770fcc
      Hugh Dickins authored 
      The kernel recovers in due course from missing Mlocked pages: but there
was no point in calling page_mlock() (formerly known as
try_to_munlock()) on a THP, because nothing got done even when it was
found to be mapped in another VM_LOCKED vma.

It's true that we need to be careful: Mlocked accounting of pte-mapped
THPs is too difficult (so consistently avoided); but Mlocked accounting
of only-pmd-mapped THPs is supposed to work, even when multiple mappings
are mlocked and munlocked or munmapped.  Refine the tests.

There is already a VM_BUG_ON_PAGE(PageDoubleMap) in page_mlock(), so
page_mlock_one() does not even have to worry about that complication.

(I said the kernel recovers: but would page reclaim be likely to split
THP before rediscovering that it's VM_LOCKED? I've not followed that up)

Fixes: 9a73f61b ("thp, mlock: do not mlock PTE-mapped file huge pages")
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/lkml/cfa154c-d595-406-eb7d-eb9df730f944@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d9770fcc
    • Hugh Dickins's avatar
      mm/rmap: fix comments left over from recent changes · 64b586d1
      Hugh Dickins authored 
      Parallel developments in mm/rmap.c have left behind some out-of-date
comments: try_to_migrate_one() also accepts TTU_SYNC (already commented
in try_to_migrate() itself), and try_to_migrate() returns nothing at
all.

TTU_SPLIT_FREEZE has just been deleted, so reword the comment about it
in mm/huge_memory.c; and TTU_IGNORE_ACCESS was removed in 5.11, so
delete the "recently referenced" comment from try_to_unmap_one() (once
upon a time the comment was near the removed codeblock, but they drifted
apart).
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Reviewed-by: default avatarAlistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/lkml/563ce5b2-7a44-5b4d-1dfd-59a0e65932a9@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      64b586d1
    • Linus Torvalds's avatar
      Merge tag 'irq-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 98f7fdce
      Linus Torvalds authored 
      Pull irq fixes from Ingo Molnar:
 "Two fixes:

   - Fix a MIPS IRQ handling RCU bug

   - Remove a DocBook annotation for a parameter that doesn't exist
     anymore"

* tag 'irq-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips: Fix RCU violation when using irqdomain lookup on interrupt entry
  genirq/irqdesc: Drop excess kernel-doc entry @lookup
      98f7fdce
    • Linus Torvalds's avatar
      Merge tag 'sched-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 877029d9
      Linus Torvalds authored 
      Pull scheduler fixes from Ingo Molnar:
 "Three fixes:

   - Fix load tracking bug/inconsistency

   - Fix a sporadic CFS bandwidth constraints enforcement bug

   - Fix a uclamp utilization tracking bug for newly woken tasks"

* tag 'sched-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/uclamp: Ignore max aggregation if rq is idle
  sched/fair: Fix CFS bandwidth hrtimer expiry type
  sched/fair: Sync load_sum with load_avg after dequeue
      877029d9
    • Linus Torvalds's avatar
      Merge tag 'perf-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 936b664f
      Linus Torvalds authored 
      Pull perf fixes from Ingo Molnar:
 "A fix and a hardware-enablement addition:

   - Robustify uncore_snbep's skx_iio_set_mapping()'s error cleanup

   - Add cstate event support for Intel ICELAKE_X and ICELAKE_D"

* tag 'perf-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Clean up error handling path of iio mapping
  perf/x86/cstate: Add ICELAKE_X and ICELAKE_D support
      936b664f
    • Linus Torvalds's avatar
      Merge tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 301c8b1d
      Linus Torvalds authored 
      Pull locking fixes from Ingo Molnar:

 - Fix a Sparc crash

 - Fix a number of objtool warnings

 - Fix /proc/lockdep output on certain configs

 - Restore a kprobes fail-safe

* tag 'locking-urgent-2021-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomic: sparc: Fix arch_cmpxchg64_local()
  kprobe/static_call: Restore missing static_call_text_reserved()
  static_call: Fix static_call_text_reserved() vs __init
  jump_label: Fix jump_label_text_reserved() vs __init
  locking/lockdep: Fix meaningless /proc/lockdep output of lock classes on !CONFIG_PROVE_LOCKING
      301c8b1d
    • Linus Torvalds's avatar
      Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 8b9cc17a
      Linus Torvalds authored 
      Pull more SCSI updates from James Bottomley:
 "This is a set of minor fixes and clean ups in the core and various
  drivers.

  The only core change in behaviour is the I/O retry for spinup notify,
  but that shouldn't impact anything other than the failing case"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (23 commits)
  scsi: virtio_scsi: Add validation for residual bytes from response
  scsi: ipr: System crashes when seeing type 20 error
  scsi: core: Retry I/O for Notify (Enable Spinup) Required error
  scsi: mpi3mr: Fix warnings reported by smatch
  scsi: qedf: Add check to synchronize abort and flush
  scsi: MAINTAINERS: Add mpi3mr driver maintainers
  scsi: libfc: Fix array index out of bound exception
  scsi: mvsas: Use DEVICE_ATTR_RO()/RW() macro
  scsi: megaraid_mbox: Use DEVICE_ATTR_ADMIN_RO() macro
  scsi: qedf: Use DEVICE_ATTR_RO() macro
  scsi: qedi: Use DEVICE_ATTR_RO() macro
  scsi: message: mptfc: Switch from pci_ to dma_ API
  scsi: be2iscsi: Fix some missing space in some messages
  scsi: be2iscsi: Fix an error handling path in beiscsi_dev_probe()
  scsi: ufs: Fix build warning without CONFIG_PM
  scsi: bnx2fc: Remove meaningless bnx2fc_abts_cleanup() return value assignment
  scsi: qla2xxx: Add heartbeat check
  scsi: virtio_scsi: Do not overwrite SCSI status
  scsi: libsas: Add LUN number check in .slave_alloc callback
  scsi: core: Inline scsi_mq_alloc_queue()
  ...
      8b9cc17a
    • Linus Torvalds's avatar
      Merge tag 'perf-tools-for-v5.14-2021-07-10' of... · b1412bd7
      Linus Torvalds authored 
      Merge tag 'perf-tools-for-v5.14-2021-07-10' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tool updates from Arnaldo Carvalho de Melo:
 "New features:

   - Enable use of BPF counters with 'perf stat --for-each-cgroup',
     using per-CPU 'cgroup-switch' events with an attached BPF program
     that does aggregation per-cgroup in the kernel instead of using
     per-cgroup perf events.

   - Add Topdown metrics L2 events as default events in 'perf stat' for
     systems having those events.

  Hardware tracing:

   - Add a config for max loops without consuming a packet in the Intel
     PT packet decoder, set via 'perf config intel-pt.max-loops=N'

  Hardware enablement:

   - Disable misleading NMI watchdog message in 'perf stat' on hybrid
     systems such as Intel Alder Lake.

   - Add a dummy event on hybrid systems to collect metadata records.

   - Add 24x7 nest metric events for the Power10 platform.

  Fixes:

   - Fix event parsing for PMUs starting with the same prefix.

   - Fix the 'perf trace' 'trace' alias installation dir.

   - Fix buffer size to report iregs in perf script python scripts,
     supporting the extended registers in PowerPC.

   - Fix overflow in elf_sec__is_text().

   - Fix 's' on source line when disasm is empty in the annotation TUI,
     accessible via 'perf annotate', 'perf report' and 'perf top'.

   - Plug leaks in scandir() returned dirent entries in 'perf test' when
     sorting the shell tests.

   - Fix --task and --stat with pipe input in 'perf report'.

   - Fix 'perf probe' use of debuginfo files by build id.

   - If a DSO has both dynsym and symtab ELF sections, read from both
     when loading the symbol table, fixing a problem processing Fedora
     32 glibc DSOs.

  Libraries:

   - Add grouping of events to libperf, from code in tools/perf,
     allowing libperf users to use that mode.

  Misc:

   - Filter plt stubs from the 'perf probe --functions' output.

   - Update UAPI header copies for asound, DRM, mman-common.h and the
     ones affected by the quotactl_fd syscall"

* tag 'perf-tools-for-v5.14-2021-07-10' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (29 commits)
  perf test: Add free() calls for scandir() returned dirent entries
  libperf: Add tests for perf_evlist__set_leader()
  libperf: Remove BUG_ON() from library code in get_group_fd()
  libperf: Add group support to perf_evsel__open()
  perf tools: Fix pattern matching for same substring in different PMU type
  perf record: Add a dummy event on hybrid systems to collect metadata records
  perf stat: Add Topdown metrics L2 events as default events
  libperf: Adopt evlist__set_leader() from tools/perf as perf_evlist__set_leader()
  libperf: Move 'nr_groups' from tools/perf to evlist::nr_groups
  libperf: Move 'leader' from tools/perf to perf_evsel::leader
  libperf: Move 'idx' from tools/perf to perf_evsel::idx
  libperf: Change tests to single static and shared binaries
  perf intel-pt: Add a config for max loops without consuming a packet
  perf stat: Disable the NMI watchdog message on hybrid
  perf vendor events power10: Adds 24x7 nest metric events for power10 platform
  perf script python: Fix buffer size to report iregs in perf script
  perf trace: Fix the perf trace link location
  perf top: Fix overflow in elf_sec__is_text()
  perf annotate: Fix 's' on source line when disasm is empty
  perf probe: Do not show @plt function by default
  ...
      b1412bd7
  17. 10 Jul, 2021 6 commits
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