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Pull kvm updates from Paolo Bonzini:
"ARM64:
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on (see merge
commit 382b5b87a97d: "Fix a number of issues with MTE, such as
races on the tags being initialised vs the PG_mte_tagged flag as
well as the lack of support for VM_SHARED when KVM is involved.
Patches from Catalin Marinas and Peter Collingbourne").
- Merge the pKVM shadow vcpu state tracking that allows the
hypervisor to have its own view of a vcpu, keeping that state
private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB
pages only) as a prefix of the oncoming support for 4kB and 16kB
pages.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
s390:
- Second batch of the lazy destroy patches
- First batch of KVM changes for kernel virtual != physical address
support
- Removal of a unused function
x86:
- Allow compiling out SMM support
- Cleanup and documentation of SMM state save area format
- Preserve interrupt shadow in SMM state save area
- Respond to generic signals during slow page faults
- Fixes and optimizations for the non-executable huge page errata
fix.
- Reprogram all performance counters on PMU filter change
- Cleanups to Hyper-V emulation and tests
- Process Hyper-V TLB flushes from a nested guest (i.e. from a L2
guest running on top of a L1 Hyper-V hypervisor)
- Advertise several new Intel features
- x86 Xen-for-KVM:
- Allow the Xen runstate information to cross a page boundary
- Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
- Add support for 32-bit guests in SCHEDOP_poll
- Notable x86 fixes and cleanups:
- One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
- Reinstate IBPB on emulated VM-Exit that was incorrectly dropped
a few years back when eliminating unnecessary barriers when
switching between vmcs01 and vmcs02.
- Clean up vmread_error_trampoline() to make it more obvious that
params must be passed on the stack, even for x86-64.
- Let userspace set all supported bits in MSR_IA32_FEAT_CTL
irrespective of the current guest CPUID.
- Fudge around a race with TSC refinement that results in KVM
incorrectly thinking a guest needs TSC scaling when running on a
CPU with a constant TSC, but no hardware-enumerated TSC
frequency.
- Advertise (on AMD) that the SMM_CTL MSR is not supported
- Remove unnecessary exports
Generic:
- Support for responding to signals during page faults; introduces
new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks
Selftests:
- Fix an inverted check in the access tracking perf test, and restore
support for asserting that there aren't too many idle pages when
running on bare metal.
- Fix build errors that occur in certain setups (unsure exactly what
is unique about the problematic setup) due to glibc overriding
static_assert() to a variant that requires a custom message.
- Introduce actual atomics for clear/set_bit() in selftests
- Add support for pinning vCPUs in dirty_log_perf_test.
- Rename the so called "perf_util" framework to "memstress".
- Add a lightweight psuedo RNG for guest use, and use it to randomize
the access pattern and write vs. read percentage in the memstress
tests.
- Add a common ucall implementation; code dedup and pre-work for
running SEV (and beyond) guests in selftests.
- Provide a common constructor and arch hook, which will eventually
be used by x86 to automatically select the right hypercall (AMD vs.
Intel).
- A bunch of added/enabled/fixed selftests for ARM64, covering
memslots, breakpoints, stage-2 faults and access tracking.
- x86-specific selftest changes:
- Clean up x86's page table management.
- Clean up and enhance the "smaller maxphyaddr" test, and add a
related test to cover generic emulation failure.
- Clean up the nEPT support checks.
- Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
- Fix an ordering issue in the AMX test introduced by recent
conversions to use kvm_cpu_has(), and harden the code to guard
against similar bugs in the future. Anything that tiggers
caching of KVM's supported CPUID, kvm_cpu_has() in this case,
effectively hides opt-in XSAVE features if the caching occurs
before the test opts in via prctl().
Documentation:
- Remove deleted ioctls from documentation
- Clean up the docs for the x86 MSR filter.
- Various fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits)
KVM: x86: Add proper ReST tables for userspace MSR exits/flags
KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
KVM: arm64: selftests: Align VA space allocator with TTBR0
KVM: arm64: Fix benign bug with incorrect use of VA_BITS
KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
KVM: x86: Advertise that the SMM_CTL MSR is not supported
KVM: x86: remove unnecessary exports
KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic"
tools: KVM: selftests: Convert clear/set_bit() to actual atomics
tools: Drop "atomic_" prefix from atomic test_and_set_bit()
tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
perf tools: Use dedicated non-atomic clear/set bit helpers
tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
KVM: arm64: selftests: Enable single-step without a "full" ucall()
KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
KVM: Remove stale comment about KVM_REQ_UNHALT
KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR
KVM: Reference to kvm_userspace_memory_region in doc and comments
KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- More userfaultfs work from Peter Xu
- Several convert-to-folios series from Sidhartha Kumar and Huang Ying
- Some filemap cleanups from Vishal Moola
- David Hildenbrand added the ability to selftest anon memory COW
handling
- Some cpuset simplifications from Liu Shixin
- Addition of vmalloc tracing support by Uladzislau Rezki
- Some pagecache folioifications and simplifications from Matthew
Wilcox
- A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use
it
- Miguel Ojeda contributed some cleanups for our use of the
__no_sanitize_thread__ gcc keyword.
This series should have been in the non-MM tree, my bad
- Naoya Horiguchi improved the interaction between memory poisoning and
memory section removal for huge pages
- DAMON cleanups and tuneups from SeongJae Park
- Tony Luck fixed the handling of COW faults against poisoned pages
- Peter Xu utilized the PTE marker code for handling swapin errors
- Hugh Dickins reworked compound page mapcount handling, simplifying it
and making it more efficient
- Removal of the autonuma savedwrite infrastructure from Nadav Amit and
David Hildenbrand
- zram support for multiple compression streams from Sergey Senozhatsky
- David Hildenbrand reworked the GUP code's R/O long-term pinning so
that drivers no longer need to use the FOLL_FORCE workaround which
didn't work very well anyway
- Mel Gorman altered the page allocator so that local IRQs can remnain
enabled during per-cpu page allocations
- Vishal Moola removed the try_to_release_page() wrapper
- Stefan Roesch added some per-BDI sysfs tunables which are used to
prevent network block devices from dirtying excessive amounts of
pagecache
- David Hildenbrand did some cleanup and repair work on KSM COW
breaking
- Nhat Pham and Johannes Weiner have implemented writeback in zswap's
zsmalloc backend
- Brian Foster has fixed a longstanding corner-case oddity in
file[map]_write_and_wait_range()
- sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang
Chen
- Shiyang Ruan has done some work on fsdax, to make its reflink mode
work better under xfstests. Better, but still not perfect
- Christoph Hellwig has removed the .writepage() method from several
filesystems. They only need .writepages()
- Yosry Ahmed wrote a series which fixes the memcg reclaim target
beancounting
- David Hildenbrand has fixed some of our MM selftests for 32-bit
machines
- Many singleton patches, as usual
* tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits)
mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio
mm: mmu_gather: allow more than one batch of delayed rmaps
mm: fix typo in struct pglist_data code comment
kmsan: fix memcpy tests
mm: add cond_resched() in swapin_walk_pmd_entry()
mm: do not show fs mm pc for VM_LOCKONFAULT pages
selftests/vm: ksm_functional_tests: fixes for 32bit
selftests/vm: cow: fix compile warning on 32bit
selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions
mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem
mm,thp,rmap: fix races between updates of subpages_mapcount
mm: memcg: fix swapcached stat accounting
mm: add nodes= arg to memory.reclaim
mm: disable top-tier fallback to reclaim on proactive reclaim
selftests: cgroup: make sure reclaim target memcg is unprotected
selftests: cgroup: refactor proactive reclaim code to reclaim_until()
mm: memcg: fix stale protection of reclaim target memcg
mm/mmap: properly unaccount memory on mas_preallocate() failure
omfs: remove ->writepage
jfs: remove ->writepage
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
"iov_iter work; most of that is about getting rid of direction
misannotations and (hopefully) preventing more of the same for the
future"
* tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
use less confusing names for iov_iter direction initializers
iov_iter: saner checks for attempt to copy to/from iterator
[xen] fix "direction" argument of iov_iter_kvec()
[vhost] fix 'direction' argument of iov_iter_{init,bvec}()
[target] fix iov_iter_bvec() "direction" argument
[s390] memcpy_real(): WRITE is "data source", not destination...
[s390] zcore: WRITE is "data source", not destination...
[infiniband] READ is "data destination", not source...
[fsi] WRITE is "data source", not destination...
[s390] copy_oldmem_kernel() - WRITE is "data source", not destination
csum_and_copy_to_iter(): handle ITER_DISCARD
get rid of unlikely() on page_copy_sane() calls
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- A ptrace API cleanup series from Sergey Shtylyov
- Fixes and cleanups for kexec from ye xingchen
- nilfs2 updates from Ryusuke Konishi
- squashfs feature work from Xiaoming Ni: permit configuration of the
filesystem's compression concurrency from the mount command line
- A series from Akinobu Mita which addresses bound checking errors when
writing to debugfs files
- A series from Yang Yingliang to address rapidio memory leaks
- A series from Zheng Yejian to address possible overflow errors in
encode_comp_t()
- And a whole shower of singleton patches all over the place
* tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (79 commits)
ipc: fix memory leak in init_mqueue_fs()
hfsplus: fix bug causing custom uid and gid being unable to be assigned with mount
rapidio: devices: fix missing put_device in mport_cdev_open
kcov: fix spelling typos in comments
hfs: Fix OOB Write in hfs_asc2mac
hfs: fix OOB Read in __hfs_brec_find
relay: fix type mismatch when allocating memory in relay_create_buf()
ocfs2: always read both high and low parts of dinode link count
io-mapping: move some code within the include guarded section
kernel: kcsan: kcsan_test: build without structleak plugin
mailmap: update email for Iskren Chernev
eventfd: change int to __u64 in eventfd_signal() ifndef CONFIG_EVENTFD
rapidio: fix possible UAF when kfifo_alloc() fails
relay: use strscpy() is more robust and safer
cpumask: limit visibility of FORCE_NR_CPUS
acct: fix potential integer overflow in encode_comp_t()
acct: fix accuracy loss for input value of encode_comp_t()
linux/init.h: include <linux/build_bug.h> and <linux/stringify.h>
rapidio: rio: fix possible name leak in rio_register_mport()
rapidio: fix possible name leaks when rio_add_device() fails
...
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git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Add NMI-safe SRCU reader API. It uses atomic_inc() instead of
this_cpu_inc() on strong load-store architectures.
- Introduce new console_list_lock to synchronize a manipulation of the
list of registered consoles and their flags.
This is a first step in removing the big-kernel-lock-like behavior of
console_lock(). This semaphore still serializes console->write()
calbacks against:
- each other. It primary prevents potential races between early
and proper console drivers using the same device.
- suspend()/resume() callbacks and init() operations in some
drivers.
- various other operations in the tty/vt and framebufer
susbsystems. It is likely that console_lock() serializes even
operations that are not directly conflicting with the
console->write() callbacks here. This is the most complicated
big-kernel-lock aspect of the console_lock() that will be hard
to untangle.
- Introduce new console_srcu lock that is used to safely iterate and
access the registered console drivers under SRCU read lock.
This is a prerequisite for introducing atomic console drivers and
console kthreads. It will reduce the complexity of serialization
against normal consoles and console_lock(). Also it should remove the
risk of deadlock during critical situations, like Oops or panic, when
only atomic consoles are registered.
- Check whether the console is registered instead of enabled on many
locations. It was a historical leftover.
- Cleanly force a preferred console in xenfb code instead of a dirty
hack.
- A lot of code and comment clean ups and improvements.
* tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits)
printk: htmldocs: add missing description
tty: serial: sh-sci: use setup() callback for early console
printk: relieve console_lock of list synchronization duties
tty: serial: kgdboc: use console_list_lock to trap exit
tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()
tty: serial: kgdboc: use console_list_lock for list traversal
tty: serial: kgdboc: use srcu console list iterator
proc: consoles: use console_list_lock for list iteration
tty: tty_io: use console_list_lock for list synchronization
printk, xen: fbfront: create/use safe function for forcing preferred
netconsole: avoid CON_ENABLED misuse to track registration
usb: early: xhci-dbc: use console_is_registered()
tty: serial: xilinx_uartps: use console_is_registered()
tty: serial: samsung_tty: use console_is_registered()
tty: serial: pic32_uart: use console_is_registered()
tty: serial: earlycon: use console_is_registered()
tty: hvc: use console_is_registered()
efi: earlycon: use console_is_registered()
tty: nfcon: use console_is_registered()
serial_core: replace uart_console_enabled() with uart_console_registered()
...
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When VM_LOCKONFAULT was added, /proc/PID/smaps wasn't hooked up to it, so
looking at /proc/PID/smaps, it shows '??' instead of something
intelligable. This can be reached by userspace by simply calling
`mlock2(..., MLOCK_ONFAULT);`.
Fix this by adding "lf" to denote VM_LOCKONFAULT.
Link: https://lkml.kernel.org/r/20221205173007.580210-1-Jason@zx2c4.com
Fixes: de60f5f10c58 ("mm: introduce VM_LOCKONFAULT")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The console_lock is used in part to guarantee safe list iteration.
The console_list_lock should be used because list synchronization
responsibility will be removed from the console_lock in a later
change.
Note, the console_lock is still needed to serialize the device()
callback with other console operations.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-35-john.ogness@linutronix.de
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The console_lock is held throughout the start/show/stop procedure
to print out device/driver information about all registered
consoles. Since the console_lock is being used for multiple reasons,
explicitly document these reasons. This will be useful when the
console_lock is split into fine-grained locking.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-11-john.ogness@linutronix.de
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Replace the open coded single linked list with a hlist so a conversion
to SRCU protected list walks can reuse the existing primitives.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-3-john.ogness@linutronix.de
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Since commit 9a10064f5625 ("mm: add a field to store names for private
anonymous memory"), name for private anonymous memory, but not shared
anonymous, can be set. However, naming shared anonymous memory just as
useful for tracking purposes.
Extend the functionality to be able to set names for shared anon.
There are two ways to create anonymous shared memory, using memfd or
directly via mmap():
1. fd = memfd_create(...)
mem = mmap(..., MAP_SHARED, fd, ...)
2. mem = mmap(..., MAP_SHARED | MAP_ANONYMOUS, -1, ...)
In both cases the anonymous shared memory is created the same way by
mapping an unlinked file on tmpfs.
The memfd way allows to give a name for anonymous shared memory, but
not useful when parts of shared memory require to have distinct names.
Example use case: The VMM maps VM memory as anonymous shared memory (not
private because VMM is sandboxed and drivers are running in their own
processes). However, the VM tells back to the VMM how parts of the memory
are actually used by the guest, how each of the segments should be backed
(i.e. 4K pages, 2M pages), and some other information about the segments.
The naming allows us to monitor the effective memory footprint for each
of these segments from the host without looking inside the guest.
Sample output:
/* Create shared anonymous segmenet */
anon_shmem = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
/* Name the segment: "MY-NAME" */
rv = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME,
anon_shmem, SIZE, "MY-NAME");
cat /proc/<pid>/maps (and smaps):
7fc8e2b4c000-7fc8f2b4c000 rw-s 00000000 00:01 1024 [anon_shmem:MY-NAME]
If the segment is not named, the output is:
7fc8e2b4c000-7fc8f2b4c000 rw-s 00000000 00:01 1024 /dev/zero (deleted)
Link: https://lkml.kernel.org/r/20221115020602.804224-1-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Colin Cross <ccross@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: xu xin <cgel.zte@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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As with PG_arch_2, this flag is only allowed on 64-bit architectures due
to the shortage of bits available. It will be used by the arm64 MTE code
in subsequent patches.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-5-pcc@google.com
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Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new
page flag for all 64-bit architectures. However, even if an architecture
is 64-bit, it may still have limited spare bits in the 'flags' member of
'struct page'. This may happen if an architecture enables SPARSEMEM
without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch.
This architecture port needs 19 more bits for the sparsemem section
information and, while it is currently fine with PG_arch_2, adding any
more PG_arch_* flags will trigger build-time warnings.
Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by
architectures that need more PG_arch_* flags beyond PG_arch_1. Select it
on arm64.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[pcc@google.com: fix build with CONFIG_ARM64_MTE disabled]
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com
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READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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SecPageTables has a tab after it instead of a space, this can break
fragile parsers that depend on spaces after the stat names.
Link: https://lkml.kernel.org/r/20221117043247.133294-1-yosryahmed@google.com
Fixes: ebc97a52b5d6cd5f ("mm: add NR_SECONDARY_PAGETABLE to count secondary page table uses.")
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Most /proc files don't have length (in fstat sense). This leads to
inefficiencies when reading such files with APIs commonly found in modern
programming languages. They open file, then fstat descriptor, get st_size
== 0 and either assume file is empty or start reading without knowing
target size.
cat(1) does OK because it uses large enough buffer by default. But naive
programs copy-pasted from SO aren't:
let mut f = std::fs::File::open("/proc/cmdline").unwrap();
let mut buf: Vec<u8> = Vec::new();
f.read_to_end(&mut buf).unwrap();
will result in
openat(AT_FDCWD, "/proc/cmdline", O_RDONLY|O_CLOEXEC) = 3
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0444, stx_size=0, ...}) = 0
lseek(3, 0, SEEK_CUR) = 0
read(3, "BOOT_IMAGE=(hd3,gpt2)/vmlinuz-5.", 32) = 32
read(3, "19.6-100.fc35.x86_64 root=/dev/m", 32) = 32
read(3, "apper/fedora_localhost--live-roo"..., 64) = 64
read(3, "ocalhost--live-swap rd.lvm.lv=fe"..., 128) = 116
read(3, "", 12)
open/stat is OK, lseek looks silly but there are 3 unnecessary reads
because Rust starts with 32 bytes per Vec<u8> and grows from there.
In case of /proc/cmdline, the length is known precisely.
Make variables readonly while I'm at it.
P.S.: I tried to scp /proc/cpuinfo today and got empty file
but this is separate story.
Link: https://lkml.kernel.org/r/YxoywlbM73JJN3r+@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Many monitoring tools include open file count as a metric. Currently the
only way to get this number is to enumerate the files in /proc/pid/fd.
The problem with the current approach is that it does many things people
generally don't care about when they need one number for a metric. In our
tests for cadvisor, which reports open file counts per cgroup, we observed
that reading the number of open files is slow. Out of 35.23% of CPU time
spent in `proc_readfd_common`, we see 29.43% spent in `proc_fill_cache`,
which is responsible for filling dentry info. Some of this extra time is
spinlock contention, but it's a contention for the lock we don't want to
take to begin with.
We considered putting the number of open files in /proc/pid/status.
Unfortunately, counting the number of fds involves iterating the
open_files bitmap, which has a linear complexity in proportion with the
number of open files (bitmap slots really, but it's close). We don't want
to make /proc/pid/status any slower, so instead we put this info in
/proc/pid/fd as a size member of the stat syscall result. Previously the
reported number was zero, so there's very little risk of breaking
anything, while still providing a somewhat logical way to count the open
files with a fallback if it's zero.
RFC for this patch included iterating open fds under RCU. Thanks to Frank
Hofmann for the suggestion to use the bitmap instead.
Previously:
```
$ sudo stat /proc/1/fd | head -n2
File: /proc/1/fd
Size: 0 Blocks: 0 IO Block: 1024 directory
```
With this patch:
```
$ sudo stat /proc/1/fd | head -n2
File: /proc/1/fd
Size: 65 Blocks: 0 IO Block: 1024 directory
```
Correctness check:
```
$ sudo ls /proc/1/fd | wc -l
65
```
I added the docs for /proc/<pid>/fd while I'm at it.
[ivan@cloudflare.com: use bitmap_weight() to count the bits]
Link: https://lkml.kernel.org/r/20221018045844.37697-1-ivan@cloudflare.com
[akpm@linux-foundation.org: include linux/bitmap.h for bitmap_weight()]
[ivan@cloudflare.com: return errno from proc_fd_getattr() instead of setting negative size]
Link: https://lkml.kernel.org/r/20221024173140.30673-1-ivan@cloudflare.com
Link: https://lkml.kernel.org/r/20220922224027.59266-1-ivan@cloudflare.com
Signed-off-by: Ivan Babrou <ivan@cloudflare.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Ivan Babrou <ivan@cloudflare.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "Some minor cleanup patches resent".
The first three patches trivial clean up patches.
And for the patch "kexec: replace crash_mem_range with range", I got a
ibm-p9wr ppc64le system to test, it works well.
This patch (of 4):
elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with
kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a
predefined value. If parse_crash_elf_headers() gets some error and
returns a negetive value, the elfcorehdr_addr should be released with
elfcorehdr_free().
Fix it by calling elfcorehdr_free() when parse_crash_elf_headers() fails.
Link: https://lkml.kernel.org/r/20220929042936.22012-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20220929042936.22012-2-bhe@redhat.com
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Lifu <chenlifu@huawei.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Li Chen <lchen@ambarella.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Most architectures (except arm64/x86/sparc) simply return 1 for
kern_addr_valid(), which is only used in read_kcore(), and it calls
copy_from_kernel_nofault() which could check whether the address is a
valid kernel address. So as there is no need for kern_addr_valid(), let's
remove it.
Link: https://lkml.kernel.org/r/20221018074014.185687-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390]
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Helge Deller <deller@gmx.de> [parisc]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Guo Ren <guoren@kernel.org> [csky]
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: <aou@eecs.berkeley.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The priority of hotplug memory callback is defined in a different file.
And there are some callers using numbers directly. Collect them together
into include/linux/memory.h for easy reading. This allows us to sort
their priorities more intuitively without additional comments.
Link: https://lkml.kernel.org/r/20220923033347.3935160-9-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: zefan li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Link: https://lkml.kernel.org/r/20220923033347.3935160-3-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: zefan li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
/proc/pid/smaps_rollup showed 0 kB for everything: now find first vma.
Link: https://lkml.kernel.org/r/3011bee7-182-97a2-1083-d5f5b688e54b@google.com
Fixes: c4c84f06285e ("fs/proc/task_mmu: stop using linked list and highest_vm_end")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- hfs and hfsplus kmap API modernization (Fabio Francesco)
- make crash-kexec work properly when invoked from an NMI-time panic
(Valentin Schneider)
- ntfs bugfixes (Hawkins Jiawei)
- improve IPC msg scalability by replacing atomic_t's with percpu
counters (Jiebin Sun)
- nilfs2 cleanups (Minghao Chi)
- lots of other single patches all over the tree!
* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
proc: test how it holds up with mapping'less process
mailmap: update Frank Rowand email address
ia64: mca: use strscpy() is more robust and safer
init/Kconfig: fix unmet direct dependencies
ia64: update config files
nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
fork: remove duplicate included header files
init/main.c: remove unnecessary (void*) conversions
proc: mark more files as permanent
nilfs2: remove the unneeded result variable
nilfs2: delete unnecessary checks before brelse()
checkpatch: warn for non-standard fixes tag style
usr/gen_init_cpio.c: remove unnecessary -1 values from int file
ipc/msg: mitigate the lock contention with percpu counter
percpu: add percpu_counter_add_local and percpu_counter_sub_local
fs/ocfs2: fix repeated words in comments
relay: use kvcalloc to alloc page array in relay_alloc_page_array
proc: make config PROC_CHILDREN depend on PROC_FS
fs: uninline inode_maybe_inc_iversion()
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"Just some boring cleanups on the sysctl front for this release"
* tag 'sysctl-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}
kernel/sysctl.c: move sysctl_vals and sysctl_long_vals to sysctl.c
sysctl: remove max_extfrag_threshold
kernel/sysctl.c: remove unnecessary (void*) conversions
proc: remove initialization assignment
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Initialize pointer hashing using the system workqueue. It avoids
taking locks in printk()/vsprintf() code path
- Misc code clean up
* tag 'printk-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: Mark __printk percpu data ready __ro_after_init
printk: Remove bogus comment vs. boot consoles
printk: Remove write only variable nr_ext_console_drivers
printk: Declare log_wait properly
printk: Make pr_flush() static
lib/vsprintf: Initialize vsprintf's pointer hash once the random core is ready.
lib/vsprintf: Remove static_branch_likely() from __ptr_to_hashval().
lib/vnsprintf: add const modifier for param 'bitmap'
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucounts update from Eric Biederman:
"Split rlimit and ucount values and max values
After the ucount rlimit code was merged a bunch of small but
siginificant bugs were found and fixed. At the time it was realized
that part of the problem was that while the ucount rlimits were very
similar to the oridinary ucounts (in being nested counts with limits)
the semantics were slightly different and the code would be less error
prone if there was less sharing.
This is the long awaited cleanup that should hopefully keep things
more comprehensible and less error prone for whoever needs to touch
that code next"
* tag 'ucount-rlimits-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ucounts: Split rlimit and ucount values and max values
|
|
Pull kvm updates from Paolo Bonzini:
"The first batch of KVM patches, mostly covering x86.
ARM:
- Account stage2 page table allocations in memory stats
x86:
- Account EPT/NPT arm64 page table allocations in memory stats
- Tracepoint cleanups/fixes for nested VM-Enter and emulated MSR
accesses
- Drop eVMCS controls filtering for KVM on Hyper-V, all known
versions of Hyper-V now support eVMCS fields associated with
features that are enumerated to the guest
- Use KVM's sanitized VMCS config as the basis for the values of
nested VMX capabilities MSRs
- A myriad event/exception fixes and cleanups. Most notably, pending
exceptions morph into VM-Exits earlier, as soon as the exception is
queued, instead of waiting until the next vmentry. This fixed a
longstanding issue where the exceptions would incorrecly become
double-faults instead of triggering a vmexit; the common case of
page-fault vmexits had a special workaround, but now it's fixed for
good
- A handful of fixes for memory leaks in error paths
- Cleanups for VMREAD trampoline and VMX's VM-Exit assembly flow
- Never write to memory from non-sleepable kvm_vcpu_check_block()
- Selftests refinements and cleanups
- Misc typo cleanups
Generic:
- remove KVM_REQ_UNHALT"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits)
KVM: remove KVM_REQ_UNHALT
KVM: mips, x86: do not rely on KVM_REQ_UNHALT
KVM: x86: never write to memory from kvm_vcpu_check_block()
KVM: x86: Don't snapshot pending INIT/SIPI prior to checking nested events
KVM: nVMX: Make event request on VMXOFF iff INIT/SIPI is pending
KVM: nVMX: Make an event request if INIT or SIPI is pending on VM-Enter
KVM: SVM: Make an event request if INIT or SIPI is pending when GIF is set
KVM: x86: lapic does not have to process INIT if it is blocked
KVM: x86: Rename kvm_apic_has_events() to make it INIT/SIPI specific
KVM: x86: Rename and expose helper to detect if INIT/SIPI are allowed
KVM: nVMX: Make an event request when pending an MTF nested VM-Exit
KVM: x86: make vendor code check for all nested events
mailmap: Update Oliver's email address
KVM: x86: Allow force_emulation_prefix to be written without a reload
KVM: selftests: Add an x86-only test to verify nested exception queueing
KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes
KVM: x86: Rename inject_pending_events() to kvm_check_and_inject_events()
KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior
KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions
KVM: x86: Morph pending exceptions to pending VM-Exits at queue time
...
|
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Pull vfs constification updates from Al Viro:
"whack-a-mole: constifying struct path *"
* tag 'pull-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ecryptfs: constify path
spufs: constify path
nd_jump_link(): constify path
audit_init_parent(): constify path
__io_setxattr(): constify path
do_proc_readlink(): constify path
overlayfs: constify path
fs/notify: constify path
may_linkat(): constify path
do_sys_name_to_handle(): constify path
->getprocattr(): attribute name is const char *, TYVM...
|
|
|
|
Mark
/proc/devices
/proc/kpagecount
/proc/kpageflags
/proc/kpagecgroup
/proc/loadavg
/proc/meminfo
/proc/softirqs
/proc/uptime
/proc/version
as permanent /proc entries, saving alloc/free and some list/spinlock ops
per use.
These files are never removed by the kernel so it is OK to mark them.
Link: https://lkml.kernel.org/r/Yyn527DzDMa+r0Yj@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 2e13ba54a268 ("fs, proc: introduce CONFIG_PROC_CHILDREN")
introduces the config PROC_CHILDREN to configure kernels to provide the
/proc/<pid>/task/<tid>/children file.
When one deselects PROC_FS for kernel builds without /proc/, the config
PROC_CHILDREN has no effect anymore, but is still visible in menuconfig.
Add the dependency on PROC_FS to make the PROC_CHILDREN option disappear
for kernel builds without /proc/.
Link: https://lkml.kernel.org/r/20220909122529.1941-1-lukas.bulwahn@gmail.com
Fixes: 2e13ba54a268 ("fs, proc: introduce CONFIG_PROC_CHILDREN")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Iago López Galeiras <iago@endocode.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
kernel/printk/printk.c:365:1: warning: symbol 'log_wait' was not declared. Should it be static?
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220924000454.3319186-3-john.ogness@linutronix.de
|
|
Patch series "ksm: count allocated rmap_items and update documentation",
v5.
KSM can save memory by merging identical pages, but also can consume
additional memory, because it needs to generate rmap_items to save each
scanned page's brief rmap information.
To determine how beneficial the ksm-policy (like madvise), they are using
brings, so we add a new interface /proc/<pid>/ksm_stat for each process
The value "ksm_rmap_items" in it indicates the total allocated ksm
rmap_items of this process.
The detailed description can be seen in the following patches' commit
message.
This patch (of 2):
KSM can save memory by merging identical pages, but also can consume
additional memory, because it needs to generate rmap_items to save each
scanned page's brief rmap information. Some of these pages may be merged,
but some may not be abled to be merged after being checked several times,
which are unprofitable memory consumed.
The information about whether KSM save memory or consume memory in
system-wide range can be determined by the comprehensive calculation of
pages_sharing, pages_shared, pages_unshared and pages_volatile. A simple
approximate calculation:
profit =~ pages_sharing * sizeof(page) - (all_rmap_items) *
sizeof(rmap_item);
where all_rmap_items equals to the sum of pages_sharing, pages_shared,
pages_unshared and pages_volatile.
But we cannot calculate this kind of ksm profit inner single-process wide
because the information of ksm rmap_item's number of a process is lacked.
For user applications, if this kind of information could be obtained, it
helps upper users know how beneficial the ksm-policy (like madvise) they
are using brings, and then optimize their app code. For example, one
application madvise 1000 pages as MERGEABLE, while only a few pages are
really merged, then it's not cost-efficient.
So we add a new interface /proc/<pid>/ksm_stat for each process in which
the value of ksm_rmap_itmes is only shown now and so more values can be
added in future.
So similarly, we can calculate the ksm profit approximately for a single
process by:
profit =~ ksm_merging_pages * sizeof(page) - ksm_rmap_items *
sizeof(rmap_item);
where ksm_merging_pages is shown at /proc/<pid>/ksm_merging_pages, and
ksm_rmap_items is shown in /proc/<pid>/ksm_stat.
Link: https://lkml.kernel.org/r/20220830143731.299702-1-xu.xin16@zte.com.cn
Link: https://lkml.kernel.org/r/20220830143838.299758-1-xu.xin16@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: CGEL ZTE <cgel.zte@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Remove references to mm_struct linked list and highest_vm_end for when
they are removed
Link: https://lkml.kernel.org/r/20220906194824.2110408-44-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Use the vma iterator instead of a for loop across the linked list. The
link list of vmas will be removed in this patch set.
Link: https://lkml.kernel.org/r/20220906194824.2110408-43-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code. Remove the vmacache
to reduce the work in keeping it up to date and code complexity.
Link: https://lkml.kernel.org/r/20220906194824.2110408-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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These users of the rbtree should probably have been walks of the linked
list, but convert them to use walks of the maple tree.
Link: https://lkml.kernel.org/r/20220906194824.2110408-17-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We've got a bunch of special swap entries that stores PFN inside the swap
offset fields. To fetch the PFN, normally the user just calls
swp_offset() assuming that'll be the PFN.
Add a helper swp_offset_pfn() to fetch the PFN instead, fetching only the
max possible length of a PFN on the host, meanwhile doing proper check
with MAX_PHYSMEM_BITS to make sure the swap offsets can actually store the
PFNs properly always using the BUILD_BUG_ON() in is_pfn_swap_entry().
One reason to do so is we never tried to sanitize whether swap offset can
really fit for storing PFN. At the meantime, this patch also prepares us
with the future possibility to store more information inside the swp
offset field, so assuming "swp_offset(entry)" to be the PFN will not stand
any more very soon.
Replace many of the swp_offset() callers to use swp_offset_pfn() where
proper. Note that many of the existing users are not candidates for the
replacement, e.g.:
(1) When the swap entry is not a pfn swap entry at all, or,
(2) when we wanna keep the whole swp_offset but only change the swp type.
For the latter, it can happen when fork() triggered on a write-migration
swap entry pte, we may want to only change the migration type from
write->read but keep the rest, so it's not "fetching PFN" but "changing
swap type only". They're left aside so that when there're more
information within the swp offset they'll be carried over naturally in
those cases.
Since at it, dropping hwpoison_entry_to_pfn() because that's exactly what
the new swp_offset_pfn() is about.
Link: https://lkml.kernel.org/r/20220811161331.37055-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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MADV_COLLAPSE is not coupled to the kernel-oriented sysfs THP settings[1].
hugepage_vma_check() is the authority on determining if a VMA is eligible
for THP allocation/collapse, and currently enforces the sysfs THP
settings. Add a flag to disable these checks. For now, only apply this
arg to anon and file, which use /sys/kernel/transparent_hugepage/enabled.
We can expand this to shmem, which uses
/sys/kernel/transparent_hugepage/shmem_enabled, later.
Use this flag in collapse_pte_mapped_thp() where previously the VMA flags
passed to hugepage_vma_check() were OR'd with VM_HUGEPAGE to elide the
VM_HUGEPAGE check in "madvise" THP mode. Prior to "mm: khugepaged: check
THP flag in hugepage_vma_check()", this check also didn't check "never"
THP mode. As such, this restores the previous behavior of
collapse_pte_mapped_thp() where sysfs THP settings are ignored. See
comment in code for justification why this is OK.
[1] https://lore.kernel.org/linux-mm/CAAa6QmQxay1_=Pmt8oCX2-Va18t44FV-Vs-WsQt_6+qBks4nZA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20220706235936.2197195-8-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Souptick Joarder (HPE)" <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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sysctl_vals and sysctl_long_vals are declared even if sysctl is disabled.
Move its definition to sysctl.c to make sure their integrity in any case.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
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The allocation address of the core_parent pointer variable is first
executed in the function, no initialization assignment is required.
Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
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Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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cast of ->d_name.name to char * is completely wrong - nothing is
allowed to modify its contents.
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We keep track of several kernel memory stats (total kernel memory, page
tables, stack, vmalloc, etc) on multiple levels (global, per-node,
per-memcg, etc). These stats give insights to users to how much memory
is used by the kernel and for what purposes.
Currently, memory used by KVM mmu is not accounted in any of those
kernel memory stats. This patch series accounts the memory pages
used by KVM for page tables in those stats in a new
NR_SECONDARY_PAGETABLE stat. This stat can be later extended to account
for other types of secondary pages tables (e.g. iommu page tables).
KVM has a decent number of large allocations that aren't for page
tables, but for most of them, the number/size of those allocations
scales linearly with either the number of vCPUs or the amount of memory
assigned to the VM. KVM's secondary page table allocations do not scale
linearly, especially when nested virtualization is in use.
From a KVM perspective, NR_SECONDARY_PAGETABLE will scale with KVM's
per-VM pages_{4k,2m,1g} stats unless the guest is doing something
bizarre (e.g. accessing only 4kb chunks of 2mb pages so that KVM is
forced to allocate a large number of page tables even though the guest
isn't accessing that much memory). However, someone would need to either
understand how KVM works to make that connection, or know (or be told) to
go look at KVM's stats if they're running VMs to better decipher the stats.
Furthermore, having NR_PAGETABLE side-by-side with NR_SECONDARY_PAGETABLE
is informative. For example, when backing a VM with THP vs. HugeTLB,
NR_SECONDARY_PAGETABLE is roughly the same, but NR_PAGETABLE is an order
of magnitude higher with THP. So having this stat will at the very least
prove to be useful for understanding tradeoffs between VM backing types,
and likely even steer folks towards potential optimizations.
The original discussion with more details about the rationale:
https://lore.kernel.org/all/87ilqoi77b.wl-maz@kernel.org
This stat will be used by subsequent patches to count KVM mmu
memory usage.
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220823004639.2387269-2-yosryahmed@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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These bits should only be valid when the ptes are present. Introducing
two booleans for it and set it to false when !pte_present() for both pte
and pmd accountings.
The bug is found during code reading and no real world issue reported, but
logically such an error can cause incorrect readings for either smaps or
smaps_rollup output on quite a few fields.
For example, it could cause over-estimate on values like Shared_Dirty,
Private_Dirty, Referenced. Or it could also cause under-estimate on
values like LazyFree, Shared_Clean, Private_Clean.
Link: https://lkml.kernel.org/r/20220805160003.58929-1-peterx@redhat.com
Fixes: b1d4d9e0cbd0 ("proc/smaps: carefully handle migration entries")
Fixes: c94b6923fa0a ("/proc/PID/smaps: Add PMD migration entry parsing")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Easily done now, just by clearing FMODE_LSEEK in ->f_mode
during proc_reg_open() for such entries.
Fixes: 868941b14441 "fs: remove no_llseek"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc updates from Andrew Morton:
"Updates to various subsystems which I help look after. lib, ocfs2,
fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
material this time"
* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
scripts/gdb: ensure the absolute path is generated on initial source
MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
mailmap: add linux.dev alias for Brendan Higgins
mailmap: update Kirill's email
profile: setup_profiling_timer() is moslty not implemented
ocfs2: fix a typo in a comment
ocfs2: use the bitmap API to simplify code
ocfs2: remove some useless functions
lib/mpi: fix typo 'the the' in comment
proc: add some (hopefully) insightful comments
bdi: remove enum wb_congested_state
kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
squashfs: support reading fragments in readahead call
squashfs: implement readahead
squashfs: always build "file direct" version of page actor
Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
fs/ocfs2: Fix spelling typo in comment
ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
proc: fix test for "vsyscall=xonly" boot option
...
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* /proc/${pid}/net status
* removing PDE vs last close stuff (again!)
* random small stuff
Link: https://lkml.kernel.org/r/YtwrM6sDC0OQ53YB@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 7bc3e6e55acf06 ("proc: Use a list of inodes to flush from proc")
moved proc_flush_task() behind __exit_signal(). Then, process systemd can
take long period high cpu usage during releasing task in following
concurrent processes:
systemd ps
kernel_waitid stat(/proc/tgid)
do_wait filename_lookup
wait_consider_task lookup_fast
release_task
__exit_signal
__unhash_process
detach_pid
__change_pid // remove task->pid_links
d_revalidate -> pid_revalidate // 0
d_invalidate(/proc/tgid)
shrink_dcache_parent(/proc/tgid)
d_walk(/proc/tgid)
spin_lock_nested(/proc/tgid/fd)
// iterating opened fd
proc_flush_pid |
d_invalidate (/proc/tgid/fd) |
shrink_dcache_parent(/proc/tgid/fd) |
shrink_dentry_list(subdirs) ↓
shrink_lock_dentry(/proc/tgid/fd) --> race on dentry lock
Function d_invalidate() will remove dentry from hash firstly, but why does
proc_flush_pid() process dentry '/proc/tgid/fd' before dentry
'/proc/tgid'? That's because proc_pid_make_inode() adds proc inode in
reverse order by invoking hlist_add_head_rcu(). But proc should not add
any inodes under '/proc/tgid' except '/proc/tgid/task/pid', fix it by
adding inode into 'pid->inodes' only if the inode is /proc/tgid or
/proc/tgid/task/pid.
Performance regression:
Create 200 tasks, each task open one file for 50,000 times. Kill all
tasks when opened files exceed 10,000,000 (cat /proc/sys/fs/file-nr).
Before fix:
$ time killall -wq aa
real 4m40.946s # During this period, we can see 'ps' and 'systemd'
taking high cpu usage.
After fix:
$ time killall -wq aa
real 1m20.732s # During this period, we can see 'systemd' taking
high cpu usage.
Link: https://lkml.kernel.org/r/20220713130029.4133533-1-chengzhihao1@huawei.com
Fixes: 7bc3e6e55acf06 ("proc: Use a list of inodes to flush from proc")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216054
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
