Merge 5708c107 on remote branch

 memory.swappiness		     set/show swappiness parameter of vmscan

				     (See sysctl's vm.swappiness)

 memory.move_charge_at_immigrate     set/show controls of moving charges

                                     This knob is deprecated and shouldn't be

                                     used.

 memory.oom_control		     set/show oom controls.

 memory.numa_stat		     show the number of memory usage per numa

				     node

       It is recommended to set the soft limit always below the hard limit,

       otherwise the hard limit will take precedence.

8. Move charges at task migration

=================================

8. Move charges at task migration (DEPRECATED!)

===============================================

THIS IS DEPRECATED!

It's expensive and unreliable! It's better practice to launch workload

tasks directly from inside their target cgroup. Use dedicated workload

cgroups to allow fine-grained policy adjustments without having to

move physical pages between control domains.

Users can move charges associated with a task along with task migration, that

is, uncharge task's pages from the old cgroup and charge them to the new cgroup.

   On Intel Skylake-era systems the mitigation covers most, but not all,

   cases. See :ref:`[3] <spec_ref3>` for more details.

   On CPUs with hardware mitigation for Spectre variant 2 (e.g. Enhanced

   IBRS on x86), retpoline is automatically disabled at run time.

   On CPUs with hardware mitigation for Spectre variant 2 (e.g. IBRS

   or enhanced IBRS on x86), retpoline is automatically disabled at run time.

   Systems which support enhanced IBRS (eIBRS) enable IBRS protection once at

   boot, by setting the IBRS bit, and they're automatically protected against

   Spectre v2 variant attacks, including cross-thread branch target injections

   on SMT systems (STIBP). In other words, eIBRS enables STIBP too.

   Legacy IBRS systems clear the IBRS bit on exit to userspace and

   therefore explicitly enable STIBP for that

   The retpoline mitigation is turned on by default on vulnerable

   CPUs. It can be forced on or off by the administrator

   For Spectre variant 2 mitigation, individual user programs

   can be compiled with return trampolines for indirect branches.

   This protects them from consuming poisoned entries in the branch

   target buffer left by malicious software.  Alternatively, the

   programs can disable their indirect branch speculation via prctl()

   (See :ref:`Documentation/userspace-api/spec_ctrl.rst <set_spec_ctrl>`).

   target buffer left by malicious software.

   On legacy IBRS systems, at return to userspace, implicit STIBP is disabled

   because the kernel clears the IBRS bit. In this case, the userspace programs

   can disable indirect branch speculation via prctl() (See

   :ref:`Documentation/userspace-api/spec_ctrl.rst <set_spec_ctrl>`).

   On x86, this will turn on STIBP to guard against attacks from the

   sibling thread when the user program is running, and use IBPB to

   flush the branch target buffer when switching to/from the program.

	ivrs_ioapic	[HW,X86_64]

			Provide an override to the IOAPIC-ID<->DEVICE-ID

			mapping provided in the IVRS ACPI table. For

			example, to map IOAPIC-ID decimal 10 to

			PCI device 00:14.0 write the parameter as:

			mapping provided in the IVRS ACPI table.

			By default, PCI segment is 0, and can be omitted.

			For example, to map IOAPIC-ID decimal 10 to

			PCI segment 0x1 and PCI device 00:14.0,

			write the parameter as:

				ivrs_ioapic=10@0001:00:14.0

			Deprecated formats:

			* To map IOAPIC-ID decimal 10 to PCI device 00:14.0

			  write the parameter as:

				ivrs_ioapic[10]=00:14.0

			* To map IOAPIC-ID decimal 10 to PCI segment 0x1 and

			  PCI device 00:14.0 write the parameter as:

				ivrs_ioapic[10]=0001:00:14.0

	ivrs_hpet	[HW,X86_64]

			Provide an override to the HPET-ID<->DEVICE-ID

			mapping provided in the IVRS ACPI table. For

			example, to map HPET-ID decimal 0 to

			PCI device 00:14.0 write the parameter as:

			mapping provided in the IVRS ACPI table.

			By default, PCI segment is 0, and can be omitted.

			For example, to map HPET-ID decimal 10 to

			PCI segment 0x1 and PCI device 00:14.0,

			write the parameter as:

				ivrs_hpet=10@0001:00:14.0

			Deprecated formats:

			* To map HPET-ID decimal 0 to PCI device 00:14.0

			  write the parameter as:

				ivrs_hpet[0]=00:14.0

			* To map HPET-ID decimal 10 to PCI segment 0x1 and

			  PCI device 00:14.0 write the parameter as:

				ivrs_ioapic[10]=0001:00:14.0

	ivrs_acpihid	[HW,X86_64]

			Provide an override to the ACPI-HID:UID<->DEVICE-ID

			mapping provided in the IVRS ACPI table. For

			example, to map UART-HID:UID AMD0020:0 to

			PCI device 00:14.5 write the parameter as:

			mapping provided in the IVRS ACPI table.

			By default, PCI segment is 0, and can be omitted.

			For example, to map UART-HID:UID AMD0020:0 to

			PCI segment 0x1 and PCI device ID 00:14.5,

			write the parameter as:

				ivrs_acpihid=AMD0020:0@0001:00:14.5

			Deprecated formats:

			* To map UART-HID:UID AMD0020:0 to PCI segment is 0,

			  PCI device ID 00:14.5, write the parameter as:

				ivrs_acpihid[00:14.5]=AMD0020:0

			* To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and

			  PCI device ID 00:14.5, write the parameter as:

				ivrs_acpihid[0001:00:14.5]=AMD0020:0

	js=		[HW,JOY] Analog joystick

			See Documentation/input/joydev/joystick.rst.

  this mode. In this case, you should build the kernel with

  CONFIG_RANDOMIZE_BASE disabled if the architecture supports KASLR.

- Build the gdb scripts (required on kernels v5.1 and above)::

    make scripts_gdb

- Enable the gdb stub of QEMU/KVM, either

    - at VM startup time by appending "-s" to the QEMU command line

	return

	-ECHILD and it will be called again in ref-walk mode.

``_weak_revalidate``

``d_weak_revalidate``

	called when the VFS needs to revalidate a "jumped" dentry.  This

	is called when a path-walk ends at dentry that was not acquired

	by doing a lookup in the parent directory.  This includes "/",