Per-cpu struct kvm_steal_time is added here, its size is 64 bytes and
also defined as 64 bytes, so that the whole structure is in one physical
page.
When a VCPU is online, function pv_enable_steal_time() is called. This
function will pass guest physical address of struct kvm_steal_time and
tells hypervisor to enable steal time. When a vcpu is offline, physical
address is set as 0 and tells hypervisor to disable steal time.
Here is an output of vmstat on guest when there is workload on both host
and guest. It shows steal time stat information.
procs -----------memory---------- -----io---- -system-- ------cpu-----
r b swpd free inact active bi bo in cs us sy id wa st
15 1 0 7583616 184112 72208 20 0 162 52 31 6 43 0 20
17 0 0 7583616 184704 72192 0 0 6318 6885 5 60 8 5 22
16 0 0 7583616 185392 72144 0 0 1766 1081 0 49 0 1 50
16 0 0 7583616 184816 72304 0 0 6300 6166 4 62 12 2 20
18 0 0 7583632 184480 72240 0 0 2814 1754 2 58 4 1 35
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
If a CPU is running either a userspace application or a guest OS in
nohz_full mode, it is possible for a system call to occur just as an
RCU grace period is starting. If that CPU also has the scheduling-clock
tick enabled for any reason (such as a second runnable task), and if the
system was booted with rcutree.use_softirq=0, then RCU can add insult to
injury by awakening that CPU's rcuc kthread, resulting in yet another
task and yet more OS jitter due to switching to that task, running it,
and switching back.
In addition, in the common case where that system call is not of
excessively long duration, awakening the rcuc task is pointless.
This pointlessness is due to the fact that the CPU will enter an extended
quiescent state upon returning to the userspace application or guest OS.
In this case, the rcuc kthread cannot do anything that the main RCU
grace-period kthread cannot do on its behalf, at least if it is given
a few additional milliseconds (for example, given the time duration
specified by rcutree.jiffies_till_first_fqs, give or take scheduling
delays).
This commit therefore adds a rcutree.nohz_full_patience_delay kernel
boot parameter that specifies the grace period age (in milliseconds,
rounded to jiffies) before which RCU will refrain from awakening the
rcuc kthread. Preliminary experimentation suggests a value of 1000,
that is, one second. Increasing rcutree.nohz_full_patience_delay will
increase grace-period latency and in turn increase memory footprint,
so systems with constrained memory might choose a smaller value.
Systems with less-aggressive OS-jitter requirements might choose the
default value of zero, which keeps the traditional immediate-wakeup
behavior, thus avoiding increases in grace-period latency.
[ paulmck: Apply Leonardo Bras feedback. ]
Link: https://lore.kernel.org/all/20240328171949.743211-1-leobras@redhat.com/
Reported-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Leonardo Bras <leobras@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
'vmap allocation for size %lu failed: use vmalloc=<size> to increase size'
The above warning is seen in the kernel functionality for allocation of
the restricted virtual memory range till exhaustion.
This message is misleading because 'vmalloc=' is supported on arm32, x86
platforms and is not a valid kernel parameter on a number of other
platforms (in particular its not supported on arm64, alpha, loongarch,
arc, csky, hexagon, microblaze, mips, nios2, openrisc, parisc, m64k,
powerpc, riscv, sh, um, xtensa, s390, sparc). With the update, the output
gets modified to include the function parameters along with the start and
end of the virtual memory range allowed.
The warning message after fix on kernel version 6.10.0-rc1+:
vmalloc_node_range for size 33619968 failed: Address range restricted between 0xffff800082640000 - 0xffff800084650000
Backtrace with the misleading error message:
vmap allocation for size 33619968 failed: use vmalloc=<size> to increase size
insmod: vmalloc error: size 33554432, vm_struct allocation failed, mode:0xcc0(GFP_KERNEL), nodemask=(null),cpuset=/,mems_allowed=0
CPU: 46 PID: 1977 Comm: insmod Tainted: G E 6.10.0-rc1+ #79
Hardware name: INGRASYS Yushan Server iSystem TEMP-S000141176+10/Yushan Motherboard, BIOS 2.10.20230517 (SCP: xxx) yyyy/mm/dd
Call trace:
dump_backtrace+0xa0/0x128
show_stack+0x20/0x38
dump_stack_lvl+0x78/0x90
dump_stack+0x18/0x28
warn_alloc+0x12c/0x1b8
__vmalloc_node_range_noprof+0x28c/0x7e0
custom_init+0xb4/0xfff8 [test_driver]
do_one_initcall+0x60/0x290
do_init_module+0x68/0x250
load_module+0x236c/0x2428
init_module_from_file+0x8c/0xd8
__arm64_sys_finit_module+0x1b4/0x388
invoke_syscall+0x78/0x108
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x3c/0x130
el0t_64_sync_handler+0x100/0x130
el0t_64_sync+0x190/0x198
[Shubhang@os.amperecomputing.com: v5]
Link: https://lkml.kernel.org/r/CH2PR01MB5894B0182EA0B28DF2EFB916F5C72@CH2PR01MB5894.prod.exchangelabs.com
Link: https://lkml.kernel.org/r/MN2PR01MB59025CC02D1D29516527A693F5C62@MN2PR01MB5902.prod.exchangelabs.com
Signed-off-by: Shubhang Kaushik <shubhang@os.amperecomputing.com>
Reviewed-by: Christoph Lameter (Ampere) <cl@linux.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Xiongwei Song <xiongwei.song@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Between kexec and confidential VM support, handling the EFI memory maps
correctly on x86 is already proving to be rather difficult (as opposed
to other EFI architectures which manage to never modify the EFI memory
map to begin with)
EFI fake memory map support is essentially a development hack (for
testing new support for the 'special purpose' and 'more reliable' EFI
memory attributes) that leaked into production code. The regions marked
in this manner are not actually recognized as such by the firmware
itself or the EFI stub (and never have), and marking memory as 'more
reliable' seems rather futile if the underlying memory is just ordinary
RAM.
Marking memory as 'special purpose' in this way is also dubious, but may
be in use in production code nonetheless. However, the same should be
achievable by using the memmap= command line option with the ! operator.
EFI fake memmap support is not enabled by any of the major distros
(Debian, Fedora, SUSE, Ubuntu) and does not exist on other
architectures, so let's drop support for it.
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull tty / serial / console fixes from Greg KH:
"Here are a bunch of fixes/reverts for 6.10-rc6. Include in here are:
- revert the bunch of tty/serial/console changes that landed in -rc1
that didn't quite work properly yet.
Everyone agreed to just revert them for now and will work on making
them better for a future release instead of trying to quick fix the
existing changes this late in the release cycle
- 8250 driver port count bugfix
- Other tiny serial port bugfixes for reported issues
All of these have been in linux-next this week with no reported
issues"
* tag 'tty-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "printk: Save console options for add_preferred_console_match()"
Revert "printk: Don't try to parse DEVNAME:0.0 console options"
Revert "printk: Flag register_console() if console is set on command line"
Revert "serial: core: Add support for DEVNAME:0.0 style naming for kernel console"
Revert "serial: core: Handle serial console options"
Revert "serial: 8250: Add preferred console in serial8250_isa_init_ports()"
Revert "Documentation: kernel-parameters: Add DEVNAME:0.0 format for serial ports"
Revert "serial: 8250: Fix add preferred console for serial8250_isa_init_ports()"
Revert "serial: core: Fix ifdef for serial base console functions"
serial: bcm63xx-uart: fix tx after conversion to uart_port_tx_limited()
serial: core: introduce uart_port_tx_limited_flags()
Revert "serial: core: only stop transmit when HW fifo is empty"
serial: imx: set receiver level before starting uart
tty: mcf: MCF54418 has 10 UARTS
serial: 8250_omap: Implementation of Errata i2310
tty: serial: 8250: Fix port count mismatch with the device
In order to allow for requesting a memory region that can be used for
things like pstore on multiple machines where the memory layout is not the
same, add a new option to the kernel command line called "reserve_mem".
The format is: reserve_mem=nn:align:name
Where it will find nn amount of memory at the given alignment of align.
The name field is to allow another subsystem to retrieve where the memory
was found. For example:
reserve_mem=12M:4096:oops ramoops.mem_name=oops
Where ramoops.mem_name will tell ramoops that memory was reserved for it
via the reserve_mem option and it can find it by calling:
if (reserve_mem_find_by_name("oops", &start, &size)) {
// start holds the start address and size holds the size given
This is typically used for systems that do not wipe the RAM, and this
command line will try to reserve the same physical memory on soft reboots.
Note, it is not guaranteed to be the same location. For example, if KASLR
places the kernel at the location of where the RAM reservation was from a
previous boot, the new reservation will be at a different location. Any
subsystem using this feature must add a way to verify that the contents of
the physical memory is from a previous boot, as there may be cases where
the memory will not be located at the same location.
Not all systems may work either. There could be bit flips if the reboot
goes through the BIOS. Using kexec to reboot the machine is likely to
have better results in such cases.
Link: https://lore.kernel.org/all/ZjJVnZUX3NZiGW6q@kernel.org/
Suggested-by: Mike Rapoport <rppt@kernel.org>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20240613155527.437020271@goodmis.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
The "tp720" switch once belonged to the ps2esdi driver, but this
driver has been removed a long time ago in 2008 in the commit
2af3e6017e ("The ps2esdi driver was marked as BROKEN more than two years ago due to being no longer working for some time.")
already, so let's remove it from the documentation now, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240617073322.40679-1-thuth@redhat.com
The string "ltpc" cannot be found in the source code anymore. This
kernel parameter likely belonged to the LocalTalk PC card module
which has been removed in commit 03dcb90dbf ("net: appletalk:
remove Apple/Farallon LocalTalk PC support"), so we should remove
it from kernel-parameters.txt now, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240614084633.560069-1-thuth@redhat.com
Add an early_params to control WFI and WFE trapping. This is to
control the degree guests can wait for interrupts on their own without
being trapped by KVM. Options for each param are trap and notrap. trap
enables the trap. notrap disables the trap. Note that when enabled,
traps are allowed but not guaranteed by the CPU architecture. Absent
an explicitly set policy, default to current behavior: disabling the
trap if only a single task is running and enabling otherwise.
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20240523174056.1565133-1-coltonlewis@google.com
[ oliver: rework kvm_vcpu_should_clear_tw*() for readability ]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Use preempt_model_preemptible() to detect a preemptible kernel when
deciding whether or not to reschedule in order to drop a contended
spinlock or rwlock. Because PREEMPT_DYNAMIC selects PREEMPTION, kernels
built with PREEMPT_DYNAMIC=y will yield contended locks even if the live
preemption model is "none" or "voluntary". In short, make kernels with
dynamically selected models behave the same as kernels with statically
selected models.
Somewhat counter-intuitively, NOT yielding a lock can provide better
latency for the relevant tasks/processes. E.g. KVM x86's mmu_lock, a
rwlock, is often contended between an invalidation event (takes mmu_lock
for write) and a vCPU servicing a guest page fault (takes mmu_lock for
read). For _some_ setups, letting the invalidation task complete even
if there is mmu_lock contention provides lower latency for *all* tasks,
i.e. the invalidation completes sooner *and* the vCPU services the guest
page fault sooner.
But even KVM's mmu_lock behavior isn't uniform, e.g. the "best" behavior
can vary depending on the host VMM, the guest workload, the number of
vCPUs, the number of pCPUs in the host, why there is lock contention, etc.
In other words, simply deleting the CONFIG_PREEMPTION guard (or doing the
opposite and removing contention yielding entirely) needs to come with a
big pile of data proving that changing the status quo is a net positive.
Opportunistically document this side effect of preempt=full, as yielding
contended spinlocks can have significant, user-visible impact.
Fixes: c597bfddc9 ("sched: Provide Kconfig support for default dynamic preempt mode")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Link: https://lore.kernel.org/kvm/ef81ff36-64bb-4cfe-ae9b-e3acf47bff24@proxmox.com
Current storage scan delay is reduced by the following old commit.
a4a47bc03f ("Lower USB storage settling delay to something more reasonable")
It means that delay is at least 'one second', or zero with delay_use=0.
'one second' is still long delay especially for embedded system but
when delay_use is set to 0 (no delay), still error observed on some USB drives.
So delay_use should not be set to 0 but 'one second' is quite long.
Especially for embedded system, it's important for end user
how quickly access to USB drive when it's connected.
That's why we have a chance to minimize such a constant long delay.
This patch optimizes scan delay more precisely
to minimize delay time but not to have any problems on USB drives
by extending module parameter 'delay_use' in milliseconds internally.
The parameter 'delay_use' optionally supports in milliseconds
if it ends with 'ms'.
It makes the range of value to 1 / 1000 in internal 32-bit value
but it's still enough to set the delay time.
By default, delay time is 'one second' for backward compatibility.
For example, it seems to be good by changing delay_use=100ms,
that is 100 millisecond delay without issues for most USB pen drives.
Signed-off-by: Norihiko Hama <Norihiko.Hama@alpsalpine.com>
Link: https://lore.kernel.org/r/20240515004339.29892-1-Norihiko.Hama@alpsalpine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On x86/ACPI platforms touchscreens mostly just work without needing any
device/model specific configuration. But in some cases (mostly with Silead
and Goodix touchscreens) it is still necessary to manually specify various
touchscreen-properties on a per model basis.
touchscreen_dmi is a special place for DMI quirks for this, but it can be
challenging for users to figure out the right property values, especially
for Silead touchscreens where non of these can be read back from
the touchscreen-controller.
ATM users can only test touchscreen properties by editing touchscreen_dmi.c
and then building a completely new kernel which makes it unnecessary
difficult for users to test and submit properties when necessary for their
laptop / tablet model.
Add support for specifying properties on the kernel commandline to allow
users to easily figure out the right settings. See the added documentation
in kernel-parameters.txt for the commandline syntax.
Cc: Gregor Riepl <onitake@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240523143601.47555-1-hdegoede@redhat.com
Pull tty / serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.10-rc1.
Included in here are:
- Usual good set of api cleanups and evolution by Jiri Slaby to make
the serial interfaces move out of the 1990's by using kfifos
instead of hand-rolling their own logic.
- 8250_exar driver updates
- max3100 driver updates
- sc16is7xx driver updates
- exar driver updates
- sh-sci driver updates
- tty ldisc api addition to help refuse bindings
- other smaller serial driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
serial: imx: Raise TX trigger level to 8
serial: 8250_pnp: Simplify "line" related code
serial: sh-sci: simplify locking when re-issuing RXDMA fails
serial: sh-sci: let timeout timer only run when DMA is scheduled
serial: sh-sci: describe locking requirements for invalidating RXDMA
serial: sh-sci: protect invalidating RXDMA on shutdown
tty: add the option to have a tty reject a new ldisc
serial: core: Call device_set_awake_path() for console port
dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
tty: serial: uartps: Add support for uartps controller reset
arm64: zynqmp: Add resets property for UART nodes
dt-bindings: serial: cdns,uart: Add optional reset property
serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
serial: 8250_exar: Keep the includes sorted
serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
serial: 8250_exar: Use BIT() in exar_ee_read()
serial: 8250_exar: Switch to use dev_err_probe()
serial: 8250_exar: Return directly from switch-cases
serial: 8250_exar: Decrease indentation level
...
Pull non-mm updates from Andrew Morton:
"Mainly singleton patches, documented in their respective changelogs.
Notable series include:
- Some maintenance and performance work for ocfs2 in Heming Zhao's
series "improve write IO performance when fragmentation is high".
- Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
exposed by fstests".
- kfifo header rework from Andy Shevchenko in the series "kfifo:
Clean up kfifo.h".
- GDB script fixes from Florian Rommel in the series "scripts/gdb:
Fixes for $lx_current and $lx_per_cpu".
- After much discussion, a coding-style update from Barry Song
explaining one reason why inline functions are preferred over
macros. The series is "codingstyle: avoid unused parameters for a
function-like macro""
* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
fs/proc: fix softlockup in __read_vmcore
nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
scripts: checkpatch: check unused parameters for function-like macro
Documentation: coding-style: ask function-like macros to evaluate parameters
nilfs2: use __field_struct() for a bitwise field
selftests/kcmp: remove unused open mode
nilfs2: remove calls to folio_set_error() and folio_clear_error()
kernel/watchdog_perf.c: tidy up kerneldoc
watchdog: allow nmi watchdog to use raw perf event
watchdog: handle comma separated nmi_watchdog command line
nilfs2: make superblock data array index computation sparse friendly
squashfs: remove calls to set the folio error flag
squashfs: convert squashfs_symlink_read_folio to use folio APIs
scripts/gdb: fix detection of current CPU in KGDB
scripts/gdb: make get_thread_info accept pointers
scripts/gdb: fix parameter handling in $lx_per_cpu
scripts/gdb: fix failing KGDB detection during probe
kfifo: don't use "proxy" headers
media: stih-cec: add missing io.h
media: rc: add missing io.h
...
Pull mm updates from Andrew Morton:
"The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.
Notable series include:
- Lucas Stach has provided some page-mapping cleanup/consolidation/
maintainability work in the series "mm/treewide: Remove pXd_huge()
API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
one test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being
allocated: number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in
largely similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene"
Johannes Weiner has fixed the page allocator's handling of
migratetype requests, with resulting improvements in compaction
efficiency.
- In the series "make the hugetlb migration strategy consistent"
Baolin Wang has fixed a hugetlb migration issue, which should
improve hugetlb allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when
memory almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting"
Kairui Song has optimized pagecache insertion, yielding ~10%
performance improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various
page->flags cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series:
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert
hugetlb functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
series "mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs.
This is a simple first-cut implementation for now. The series is
"support multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in
the series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts
in the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call
it GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
path to use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes".
Fixes the initialization code so that migration between different
memory types works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant
driver in the series "mm: follow_pte() improvements and acrn
follow_pte() fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to
folio in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size
THP's in the series "mm: add per-order mTHP alloc and swpout
counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap
same-filled and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His
series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
optimizes the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback
instrumentation in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series
"Fix and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
the series "Improve anon_vma scalability for anon VMAs". Intel's
test bot reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as
XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking""
* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
selftests: cgroup: add tests to verify the zswap writeback path
mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
mm/damon/core: fix return value from damos_wmark_metric_value
mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
selftests: cgroup: remove redundant enabling of memory controller
Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
Docs/mm/damon/design: use a list for supported filters
Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
selftests/damon: classify tests for functionalities and regressions
selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
selftests/damon: add a test for DAMOS quota goal
...
Pull arm64 updates from Will Deacon:
"The most interesting parts are probably the mm changes from Ryan which
optimise the creation of the linear mapping at boot and (separately)
implement write-protect support for userfaultfd.
Outside of our usual directories, the Kbuild-related changes under
scripts/ have been acked by Masahiro whilst the drivers/acpi/ parts
have been acked by Rafael and the addition of cpumask_any_and_but()
has been acked by Yury.
ACPI:
- Support for the Firmware ACPI Control Structure (FACS) signature
feature which is used to reboot out of hibernation on some systems
Kbuild:
- Support for building Flat Image Tree (FIT) images, where the kernel
Image is compressed alongside a set of devicetree blobs
Memory management:
- Optimisation of our early page-table manipulation for creation of
the linear mapping
- Support for userfaultfd write protection, which brings along some
nice cleanups to our handling of invalid but present ptes
- Extend our use of range TLBI invalidation at EL1
Perf and PMUs:
- Ensure that the 'pmu->parent' pointer is correctly initialised by
PMU drivers
- Avoid allocating 'cpumask_t' types on the stack in some PMU drivers
- Fix parsing of the CPU PMU "version" field in assembly code, as it
doesn't follow the usual architectural rules
- Add best-effort unwinding support for USER_STACKTRACE
- Minor driver fixes and cleanups
Selftests:
- Minor cleanups to the arm64 selftests (missing NULL check, unused
variable)
Miscellaneous:
- Add a command-line alias for disabling 32-bit application support
- Add part number for Neoverse-V2 CPUs
- Minor fixes and cleanups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
arm64/mm: Fix pud_user_accessible_page() for PGTABLE_LEVELS <= 2
arm64/mm: Add uffd write-protect support
arm64/mm: Move PTE_PRESENT_INVALID to overlay PTE_NG
arm64/mm: Remove PTE_PROT_NONE bit
arm64/mm: generalize PMD_PRESENT_INVALID for all levels
arm64: simplify arch_static_branch/_jump function
arm64: Add USER_STACKTRACE support
arm64: Add the arm64.no32bit_el0 command line option
drivers/perf: hisi: hns3: Actually use devm_add_action_or_reset()
drivers/perf: hisi: hns3: Fix out-of-bound access when valid event group
drivers/perf: hisi_pcie: Fix out-of-bound access when valid event group
kselftest: arm64: Add a null pointer check
arm64: defer clearing DAIF.D
arm64: assembler: update stale comment for disable_step_tsk
arm64/sysreg: Update PIE permission encodings
kselftest/arm64: Remove unused parameters in abi test
perf/arm-spe: Assign parents for event_source device
perf/arm-smmuv3: Assign parents for event_source device
perf/arm-dsu: Assign parents for event_source device
perf/arm-dmc620: Assign parents for event_source device
...
Pull x86 interrupt handling updates from Thomas Gleixner:
"Add support for posted interrupts on bare metal.
Posted interrupts is a virtualization feature which allows to inject
interrupts directly into a guest without host interaction. The VT-d
interrupt remapping hardware sets the bit which corresponds to the
interrupt vector in a vector bitmap which is either used to inject the
interrupt directly into the guest via a virtualized APIC or in case
that the guest is scheduled out provides a host side notification
interrupt which informs the host that an interrupt has been marked
pending in the bitmap.
This can be utilized on bare metal for scenarios where multiple
devices, e.g. NVME storage, raise interrupts with a high frequency. In
the default mode these interrupts are handles independently and
therefore require a full roundtrip of interrupt entry/exit.
Utilizing posted interrupts this roundtrip overhead can be avoided by
coalescing these interrupt entries to a single entry for the posted
interrupt notification. The notification interrupt then demultiplexes
the pending bits in a memory based bitmap and invokes the
corresponding device specific handlers.
Depending on the usage scenario and device utilization throughput
improvements between 10% and 130% have been measured.
As this is only relevant for high end servers with multiple device
queues per CPU attached and counterproductive for situations where
interrupts are arriving at distinct times, the functionality is opt-in
via a kernel command line parameter"
* tag 'x86-irq-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/irq: Use existing helper for pending vector check
iommu/vt-d: Enable posted mode for device MSIs
iommu/vt-d: Make posted MSI an opt-in command line option
x86/irq: Extend checks for pending vectors to posted interrupts
x86/irq: Factor out common code for checking pending interrupts
x86/irq: Install posted MSI notification handler
x86/irq: Factor out handler invocation from common_interrupt()
x86/irq: Set up per host CPU posted interrupt descriptors
x86/irq: Reserve a per CPU IDT vector for posted MSIs
x86/irq: Add a Kconfig option for posted MSI
x86/irq: Remove bitfields in posted interrupt descriptor
x86/irq: Unionize PID.PIR for 64bit access w/o casting
KVM: VMX: Move posted interrupt descriptor out of VMX code
Pull scheduler updates from Ingo Molnar:
- Add cpufreq pressure feedback for the scheduler
- Rework misfit load-balancing wrt affinity restrictions
- Clean up and simplify the code around ::overutilized and
::overload access.
- Simplify sched_balance_newidle()
- Bump SCHEDSTAT_VERSION to 16 due to a cleanup of CPU_MAX_IDLE_TYPES
handling that changed the output.
- Rework & clean up <asm/vtime.h> interactions wrt arch_vtime_task_switch()
- Reorganize, clean up and unify most of the higher level
scheduler balancing function names around the sched_balance_*()
prefix
- Simplify the balancing flag code (sched_balance_running)
- Miscellaneous cleanups & fixes
* tag 'sched-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
sched/pelt: Remove shift of thermal clock
sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()
thermal/cpufreq: Remove arch_update_thermal_pressure()
sched/cpufreq: Take cpufreq feedback into account
cpufreq: Add a cpufreq pressure feedback for the scheduler
sched/fair: Fix update of rd->sg_overutilized
sched/vtime: Do not include <asm/vtime.h> header
s390/irq,nmi: Include <asm/vtime.h> header directly
s390/vtime: Remove unused __ARCH_HAS_VTIME_TASK_SWITCH leftover
sched/vtime: Get rid of generic vtime_task_switch() implementation
sched/vtime: Remove confusing arch_vtime_task_switch() declaration
sched/balancing: Simplify the sg_status bitmask and use separate ->overloaded and ->overutilized flags
sched/fair: Rename set_rd_overutilized_status() to set_rd_overutilized()
sched/fair: Rename SG_OVERLOAD to SG_OVERLOADED
sched/fair: Rename {set|get}_rd_overload() to {set|get}_rd_overloaded()
sched/fair: Rename root_domain::overload to ::overloaded
sched/fair: Use helper functions to access root_domain::overload
sched/fair: Check root_domain::overload value before update
sched/fair: Combine EAS check with root_domain::overutilized access
sched/fair: Simplify the continue_balancing logic in sched_balance_newidle()
...
Pull documentation updates from Jonathan Corbet:
"Another not-too-busy cycle for documentation, including:
- Some build-system changes to detect the variable fonts installed by
some distributions that can break the PDF build.
- Various updates and additions to the Spanish, Chinese, Italian, and
Japanese translations.
- Update the stable-kernel rules to match modern practice
... and the usual array of corrections, updates, and typo fixes"
* tag 'docs-6.10' of git://git.lwn.net/linux: (42 commits)
cgroup: Add documentation for missing zswap memory.stat
kernel-doc: Added "*" in $type_constants2 to fix 'make htmldocs' warning.
docs:core-api: fixed typos and grammar in printk-index page
Documentation: tracing: Fix spelling mistakes
docs/zh_CN/rust: Update the translation of quick-start to 6.9-rc4
docs/zh_CN/rust: Update the translation of general-information to 6.9-rc4
docs/zh_CN/rust: Update the translation of coding-guidelines to 6.9-rc4
docs/zh_CN/rust: Update the translation of arch-support to 6.9-rc4
docs: stable-kernel-rules: fix typo sent->send
docs/zh_CN: remove two inconsistent spaces
docs: scripts/check-variable-fonts.sh: Improve commands for detection
docs: stable-kernel-rules: create special tag to flag 'no backporting'
docs: stable-kernel-rules: explain use of stable@kernel.org (w/o @vger.)
docs: stable-kernel-rules: remove code-labels tags and a indention level
docs: stable-kernel-rules: call mainline by its name and change example
docs: stable-kernel-rules: reduce redundancy
docs, kprobes: Add riscv as supported architecture
Docs: typos/spelling
docs: kernel_include.py: Cope with docutils 0.21
docs: ja_JP/howto: Catch up update in v6.8
...
Pull trusted keys updates from Jarkko Sakkinen:
"This contains a new key type for the Data Co-Processor (DCP), which is
an IP core built into many NXP SoCs such as i.mx6ull"
* tag 'keys-trusted-next-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
docs: trusted-encrypted: add DCP as new trust source
docs: document DCP-backed trusted keys kernel params
MAINTAINERS: add entry for DCP-based trusted keys
KEYS: trusted: Introduce NXP DCP-backed trusted keys
KEYS: trusted: improve scalability of trust source config
crypto: mxs-dcp: Add support for hardware-bound keys
Pull RCU updates from Uladzislau Rezki:
- Fix a lockdep complain for lazy-preemptible kernel, remove redundant
BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix
false positives KCSAN splat and fix buffer overflow in the
print_cpu_stall_info().
- Misc updates related to bpf, tracing and update the MAINTAINERS file.
- An improvement of a normal synchronize_rcu() call in terms of
latency. It maintains a separate track for sync. users only. This
approach bypasses per-cpu nocb-lists thus sync-users do not depend on
nocb-list length and how fast regular callbacks are processed.
- RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE
priority, fix some comments, add some diagnostic warning to the
exit_tasks_rcu_start() and fix a buffer overflow in the
show_rcu_tasks_trace_gp_kthread().
- RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU
testing, some updates for TREE09, dump mode information to debug GP
kthread state, remove redundant READ_ONCE(), fix some comments about
RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer
initialization, fix a hung splat task by when the rcutorture tests
start to exit, fix invalid context warning, add '--do-kvfree'
parameter to torture test and use slow register unregister callbacks
only for rcutype test.
* tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits)
rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test
torture: Scale --do-kvfree test time
rcutorture: Fix invalid context warning when enable srcu barrier testing
rcutorture: Make stall-tasks directly exit when rcutorture tests end
rcutorture: Removing redundant function pointer initialization
rcutorture: Make rcutorture support print rcu-tasks gp state
rcutorture: Use the gp_kthread_dbg operation specified by cur_ops
rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading
rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment
rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE()
rcu: Allocate WQ with WQ_MEM_RECLAIM bit set
rcu: Support direct wake-up of synchronize_rcu() users
rcu: Add a trace event for synchronize_rcu_normal()
rcu: Reduce synchronize_rcu() latency
rcu: Fix buffer overflow in print_cpu_stall_info()
rcu: Mollify sparse with RCU guard
rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow
rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer
rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE()
rcu: Remove redundant CONFIG_PROVE_RCU #if condition
...
Pull s390 updates from Alexander Gordeev:
- Store AP Query Configuration Information in a static buffer
- Rework the AP initialization and add missing cleanups to the error
path
- Swap IRQ and AP bus/device registration to avoid race conditions
- Export prot_virt_guest symbol
- Introduce AP configuration changes notifier interface to facilitate
modularization of the AP bus
- Add CONFIG_AP kernel configuration option to allow modularization of
the AP bus
- Rework CONFIG_ZCRYPT_DEBUG kernel configuration option description
and dependency and rename it to CONFIG_AP_DEBUG
- Convert sprintf() and snprintf() to sysfs_emit() in CIO code
- Adjust indentation of RELOCS command build step
- Make crypto performance counters upward compatible
- Convert make_page_secure() and gmap_make_secure() to use folio
- Rework channel-utilization-block (CUB) handling in preparation of
introducing additional CUBs
- Use attribute groups to simplify registration, removal and extension
of measurement-related channel-path sysfs attributes
- Add a per-channel-path binary "ext_measurement" sysfs attribute that
provides access to extended channel-path measurement data
- Export measurement data for all channel-measurement-groups (CMG), not
only for a specific ones. This enables support of new CMG data
formats in userspace without the need for kernel changes
- Add a per-channel-path sysfs attribute "speed_bps" that provides the
operating speed in bits per second or 0 if the operating speed is not
available
- The CIO tracepoint subchannel-type field "st" is incorrectly set to
the value of subchannel-enabled SCHIB "ena" field. Fix that
- Do not forcefully limit vmemmap starting address to MAX_PHYSMEM_BITS
- Consider the maximum physical address available to a DCSS segment
(512GB) when memory layout is set up
- Simplify the virtual memory layout setup by reducing the size of
identity mapping vs vmemmap overlap
- Swap vmalloc and Lowcore/Real Memory Copy areas in virtual memory.
This will allow to place the kernel image next to kernel modules
- Move everyting KASLR related from <asm/setup.h> to <asm/page.h>
- Put virtual memory layout information into a structure to improve
code generation
- Currently __kaslr_offset is the kernel offset in both physical and
virtual memory spaces. Uncouple these offsets to allow uncoupling of
the addresses spaces
- Currently the identity mapping base address is implicit and is always
set to zero. Make it explicit by putting into __identity_base
persistent boot variable and use it in proper context
- Introduce .amode31 section start and end macros AMODE31_START and
AMODE31_END
- Introduce OS_INFO entries that do not reference any data in memory,
but rather provide only values
- Store virtual memory layout in OS_INFO. It is read out by
makedumpfile, crash and other tools
- Store virtual memory layout in VMCORE_INFO. It is read out by crash
and other tools when /proc/kcore device is used
- Create additional PT_LOAD ELF program header that covers kernel image
only, so that vmcore tools could locate kernel text and data when
virtual and physical memory spaces are uncoupled
- Uncouple physical and virtual address spaces
- Map kernel at fixed location when KASLR mode is disabled. The
location is defined by CONFIG_KERNEL_IMAGE_BASE kernel configuration
value.
- Rework deployment of kernel image for both compressed and
uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel
configuration value
- Move .vmlinux.relocs section in front of the compressed kernel. The
interim section rescue step is avoided as result
- Correct modules thunk offset calculation when branch target is more
than 2GB away
- Kernel modules contain their own set of expoline thunks. Now that the
kernel modules area is less than 4GB away from kernel expoline
thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN
the default if the compiler supports it
- userfaultfd can insert shared zeropages into processes running VMs,
but that is not allowed for s390. Fallback to allocating a fresh
zeroed anonymous folio and insert that instead
- Re-enable shared zeropages for non-PV and non-skeys KVM guests
- Rename hex2bitmap() to ap_hex2bitmap() and export it for external use
- Add ap_config sysfs attribute to provide the means for setting or
displaying adapters, domains and control domains assigned to a
vfio-ap mediated device in a single operation
- Make vfio_ap_mdev_link_queue() ignore duplicate link requests
- Add write support to ap_config sysfs attribute to allow atomic update
a vfio-ap mediated device state
- Document ap_config sysfs attribute
- Function os_info_old_init() is expected to be called only from a
regular kdump kernel. Enable it to be called from a stand-alone dump
kernel
- Address gcc -Warray-bounds warning and fix array size in struct
os_info
- s390 does not support SMBIOS, so drop unneeded CONFIG_DMI checks
- Use unwinder instead of __builtin_return_address() with ftrace to
prevent returning of undefined values
- Sections .hash and .gnu.hash are only created when CONFIG_PIE_BUILD
kernel is enabled. Drop these for the case CONFIG_PIE_BUILD is
disabled
- Compile kernel with -fPIC and link with -no-pie to allow kpatch
feature always succeed and drop the whole CONFIG_PIE_BUILD
option-enabled code
- Add missing virt_to_phys() converter for VSIE facility and crypto
control blocks
* tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
Revert "s390: Relocate vmlinux ELF data to virtual address space"
KVM: s390: vsie: Use virt_to_phys for crypto control block
s390: Relocate vmlinux ELF data to virtual address space
s390: Compile kernel with -fPIC and link with -no-pie
s390: vmlinux.lds.S: Drop .hash and .gnu.hash for !CONFIG_PIE_BUILD
s390/ftrace: Use unwinder instead of __builtin_return_address()
s390/pci: Drop unneeded reference to CONFIG_DMI
s390/os_info: Fix array size in struct os_info
s390/os_info: Initialize old os_info in standalone dump kernel
docs: Update s390 vfio-ap doc for ap_config sysfs attribute
s390/vfio-ap: Add write support to sysfs attr ap_config
s390/vfio-ap: Ignore duplicate link requests in vfio_ap_mdev_link_queue
s390/vfio-ap: Add sysfs attr, ap_config, to export mdev state
s390/ap: Externalize AP bus specific bitmap reading function
s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests
mm/userfaultfd: Do not place zeropages when zeropages are disallowed
s390/expoline: Make modules use kernel expolines
s390/nospec: Correct modules thunk offset calculation
s390/boot: Do not rescue .vmlinux.relocs section
s390/boot: Rework deployment of the kernel image
...
Pull pci fixes from Bjorn Helgaas:
- Update kernel-parameters doc to describe "pcie_aspm=off" more
accurately (Bjorn Helgaas)
- Restore the parent's (not the child's) ASPM state to the parent
during resume, which fixes a reboot during resume (Kai-Heng Feng)
* tag 'pci-v6.9-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/ASPM: Restore parent state to parent, child state to child
PCI/ASPM: Clarify that pcie_aspm=off means leave ASPM untouched
NMI watchdog permanently consumes one hardware counters per CPU on the
system. For systems that use many hardware counters, this causes more
aggressive time multiplexing of perf events.
OTOH, some CPUs (mostly Intel) support "ref-cycles" event, which is rarely
used. Add kernel cmdline arg nmi_watchdog=rNNN to configure the watchdog
to use raw event. For example, on Intel CPUs, we can use "r300" to
configure the watchdog to use ref-cycles event.
If the raw event does not work, fall back to use "cycles".
[akpm@linux-foundation.org: fix kerneldoc]
Link: https://lkml.kernel.org/r/20240430060236.1878002-2-song@kernel.org
Signed-off-by: Song Liu <song@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously we claimed "pcie_aspm=off" meant that ASPM would be disabled,
which is wrong.
Correct this to say that with "pcie_aspm=off", Linux doesn't touch any ASPM
configuration at all. ASPM may have been enabled by firmware, and that
will be left unchanged. See "aspm_support_enabled".
Link: https://lore.kernel.org/r/20240429191821.691726-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: David E. Box <david.e.box@linux.intel.com>
Implements the "init_mlocked_on_free" boot option. When this boot option
is enabled, any mlock'ed pages are zeroed on free. If
the pages are munlock'ed beforehand, no initialization takes place.
This boot option is meant to combat the performance hit of
"init_on_free" as reported in commit 6471384af2 ("mm: security:
introduce init_on_alloc=1 and init_on_free=1 boot options"). With
"init_mlocked_on_free=1" only relevant data is freed while everything
else is left untouched by the kernel. Correspondingly, this patch
introduces no performance hit for unmapping non-mlock'ed memory. The
unmapping overhead for purely mlocked memory was measured to be
approximately 13%. Realistically, most systems mlock only a fraction of
the total memory so the real-world system overhead should be close to
zero.
Optimally, userspace programs clear any key material or other
confidential memory before exit and munlock the according memory
regions. If a program crashes, userspace key managers fail to do this
job. Accordingly, no munlock operations are performed so the data is
caught and zeroed by the kernel. Should the program not crash, all
memory will ideally be munlocked so no overhead is caused.
CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON can be set to enable
"init_mlocked_on_free" by default.
Link: https://lkml.kernel.org/r/20240329145605.149917-1-yjnworkstation@gmail.com
Signed-off-by: York Jasper Niebuhr <yjnworkstation@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: York Jasper Niebuhr <yjnworkstation@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Explicitly disallow enabling mitigations at runtime for kernels that were
built with CONFIG_CPU_MITIGATIONS=n, as some architectures may omit code
entirely if mitigations are disabled at compile time.
E.g. on x86, a large pile of Kconfigs are buried behind CPU_MITIGATIONS,
and trying to provide sane behavior for retroactively enabling mitigations
is extremely difficult, bordering on impossible. E.g. page table isolation
and call depth tracking require build-time support, BHI mitigations will
still be off without additional kernel parameters, etc.
[ bp: Touchups. ]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240420000556.2645001-3-seanjc@google.com
Commit 839195352d ("mm/shuffle: remove dynamic reconfiguration")
removed the dynamic reconfiguration capabilities from the shuffle page
allocator. This means that, now, we don't have any perspective of an
"autodetection of memory-side-cache" that triggers the enablement of the
shuffle page allocator.
Therefore, let the documentation reflect that the only way to enable
the shuffle page allocator is by setting `page_alloc.shuffle=1`.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240422142007.1062231-1-mcanal@igalia.com
We want the tty fixes in here as well, and it resolves a merge conflict
in:
drivers/tty/serial/serial_core.c
as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
