Currently a key has a standard matching criteria of { type, description }
and this is used to only allow keys with unique criteria in a keyring.
This means, however, that you cannot have keys with the same type and
description but a different target namespace in the same keyring.
This is a potential problem for a containerised environment where, say, a
container is made up of some parts of its mount space involving netfs
superblocks from two different network namespaces.
This is also a problem for shared system management keyrings such as the
DNS records keyring or the NFS idmapper keyring that might contain keys
from different network namespaces.
Fix this by including a namespace component in a key's matching criteria.
Keyring types are marked to indicate which, if any, namespace is relevant
to keys of that type, and that namespace is set when the key is created
from the current task's namespace set.
The capability bit KEYCTL_CAPS1_NS_KEY_TAG is set if the kernel is
employing this feature.
Signed-off-by: David Howells <dhowells@redhat.com>
Move the user and user-session keyrings to the user_namespace struct rather
than pinning them from the user_struct struct. This prevents these
keyrings from propagating across user-namespaces boundaries with regard to
the KEY_SPEC_* flags, thereby making them more useful in a containerised
environment.
The issue is that a single user_struct may be represent UIDs in several
different namespaces.
The way the patch does this is by attaching a 'register keyring' in each
user_namespace and then sticking the user and user-session keyrings into
that. It can then be searched to retrieve them.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jann Horn <jannh@google.com>
Keyring names are held in a single global list that any process can pick
from by means of keyctl_join_session_keyring (provided the keyring grants
Search permission). This isn't very container friendly, however.
Make the following changes:
(1) Make default session, process and thread keyring names begin with a
'.' instead of '_'.
(2) Keyrings whose names begin with a '.' aren't added to the list. Such
keyrings are system specials.
(3) Replace the global list with per-user_namespace lists. A keyring adds
its name to the list for the user_namespace that it is currently in.
(4) When a user_namespace is deleted, it just removes itself from the
keyring name list.
The global keyring_name_lock is retained for accessing the name lists.
This allows (4) to work.
This can be tested by:
# keyctl newring foo @s
995906392
# unshare -U
$ keyctl show
...
995906392 --alswrv 65534 65534 \_ keyring: foo
...
$ keyctl session foo
Joined session keyring: 935622349
As can be seen, a new session keyring was created.
The capability bit KEYCTL_CAPS1_NS_KEYRING_NAME is set if the kernel is
employing this feature.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.
Signed-off-by: David Howells <dhowells@redhat.com>
Cache the hash of the key's type and description in the index key so that
we're not recalculating it every time we look at a key during a search.
The hash function does a bunch of multiplications, so evading those is
probably worthwhile - especially as this is done for every key examined
during a search.
This also allows the methods used by assoc_array to get chunks of index-key
to be simplified.
Signed-off-by: David Howells <dhowells@redhat.com>
Simplify key description management by cramming the word containing the
length with the first few chars of the description also. This simplifies
the code that generates the index-key used by assoc_array. It should speed
up key searching a bit too.
Signed-off-by: David Howells <dhowells@redhat.com>
In vport metadata matching, source port number is replaced by metadata.
While FW has no idea about what it is in the metadata, a syndrome will
happen. Specify a known origin to avoid the syndrome.
However, there is no functional change because ANY_VPORT (0) is filled
in flow_source, the same default value as before, as a pre-step towards
metadata matching for fast path.
There are two other values can be filled in flow_source. When setting
0x1, packet matching this rule is from uplink, while 0x2 is for packet
from other local vports.
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
When a dual-port VHCA sends a RoCE packet on its non-native port, and the
packet arrives to its affiliated vport FDB, a mismatch might occur on the
rules that match the packet source vport as it is not represented by single
VHCA only in this case. So we change to match on metadata instead of source
vport.
To do that, a rule is created in all vports and uplink ingress ACLs, to
save the source vport number and vhca id in the packet's metadata in order
to match on it later.
The metadata register used is the first of the 32-bit type C registers. It
can be used for matching and header modify operations. The higher 16 bits
of this register are for vhca id, and the lower 16 ones is for vport
number.
This change is not for dual-port RoCE only. If HW and FW allow, the vport
metadata matching is enabled by default.
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Refactor the flow data structures, add new flow_context and move
flow_tag into it, as flow_tag doesn't belong to the rule action.
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
When a dual-port VHCA sends a RoCE packet on its non-native port, and
the packet arrives to its affiliated vport FDB, a mismatch might occur
on the rules that match the packet source vport. So we replace the
match on source port with the match on metadata that was configured in
ingress ACL, and that metadata will be passed further also to the NIC
RX table of the eswitch manager.
Introduce vport metadata matching bits and enum constants as a pre-step
towards metadata matching.
o metadata type C registers in the misc parameters 2 fields.
o esw_uplink_ingress_acl bit in esw cap. If it set, the device supports
ingress ACL for the uplink vport.
o fdb_to_vport_reg_* bits in flow table cap and esw vport context, to
support propagating the metadata to the nic rx through the loopback
path.
o flow_source in flow context, to indicate the known origin of packets.
o enum constants, to support the above bits.
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
This patch fixes 'NIC Link is Up, Unknown bps' message in dmesg
for 2.5Gb/5Gb speeds. This problem is fixed by adding constants
for VIRTCHNL_LINK_SPEED_2_5GB and VIRTCHNL_LINK_SPEED_5GB cases
in the i40e_virtchnl_link_speed() function.
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Currently, in suspend() and resume(), ishtp client drivers are using
driver_data to get "struct ishtp_cl_device" object which is set by
bus driver. It's wrong since the driver_data should not be owned bus.
driver_data should be owned by the corresponding ishtp client driver.
Due to this, some ishtp client driver like cros_ec_ishtp which uses
its driver_data to transfer its data to its child doesn't work correctly.
So this patch removes setting driver_data in bus drier and instead of
using driver_data to get "struct ishtp_cl_device", since "struct device"
is embedded in "struct ishtp_cl_device", we introduce a helper function
that returns "struct ishtp_cl_device" from "struct device".
Signed-off-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
In analogy to referencing a GPIO using the "gpios" property from ACPI,
support referencing a PWM using the "pwms" property.
ACPI entries must look like
Package () {"pwms", Package ()
{ <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
In contrast to the DT implementation, only _one_ PWM entry in the "pwms"
property is supported. As a consequence "pwm-names"-property and
con_id lookup aren't supported.
Support for ACPI is added via the firmware-node framework which is an
abstraction layer on top of ACPI/DT. To keep this patch clean, DT and
ACPI paths are kept separate. The firmware-node framework could be used
to unify both paths in a future patch.
To support leds-pwm driver, an additional method devm_fwnode_pwm_get()
which supports both ACPI and DT configuration is exported.
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
[thierry.reding@gmail.com: fix build failures for !ACPI]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
cpufreq_online() and cpufreq_offline() [un]register the driver as
a cooling device. This is done if the driver is flagged as a cooling
device in addition with an IS_ENABLED() check to compile out the branching
code.
Group this test in a stub function added in the cpufreq header instead
of having the IS_ENABLED() in the code.
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull operating performance points (OPP) framework changes for v5.3
from Viresh Kumar:
"This pull request contains:
- OPP core changes to support a wider range of devices, like IO
devices (Rajendra Nayak and Stehpen Boyd).
- Fixes around genpd_virt_devs (Viresh Kumar).
- Fix for platform with set_opp() callback (Dmitry Osipenko)."
* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
opp: Don't use IS_ERR on invalid supplies
opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes
opp: Don't overwrite rounded clk rate
opp: Allocate genpd_virt_devs from dev_pm_opp_attach_genpd()
opp: Attach genpds to devices from within OPP core
In the future, each struct renesas_usbhs_driver_param is stored on
the each platform related source code (e.g. rcar3.c). So, to simplify
the source code, this patch adds a new flag has_new_pipe_configs.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To remove the type of renesas_usbhs_driver_param in the future, this
patch uses a specific flag "multi_clks".
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The notify_hotplug callback was supported in v3.10, but the last user
(armadillo800eva) was removed by the commit 1fa59bda21 ("ARM: shmobile:
Remove legacy board code for Armadillo-800 EVA"). So, this patch
removes it.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add managed version of the clk_bulk_get_optional() helper function.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
[sboyd@kernel.org: Mark __devm_clk_bulk_get() static]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
clk_bulk_get_optional() allows to get a group of clocks where one
or more is optional. For a not available clock, e.g. not specifed
in the clock consumer node in DT, its respective struct clk pointer
will be NULL. This allows for operating on a group of returned
clocks (struct clk_bulk_data array) with existing clk_bulk* APIs.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Added a measurement of completions per/msec to allow for completion based
dim algorithms.
In order to use dynamic interrupt moderation with RDMA we need to have a
different measurment than packets per second. This change is meant to
prepare for adding a new DIM method.
All drivers that use net_dim and thus do not need a completion count will
have the completions set to 0.
Signed-off-by: Yamin Friedman <yaminf@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Moved all logic from dim.h and net_dim.h to dim.c and net_dim.c.
This is both more structurally appealing and would allow to only
expose externally used functions.
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Removed 'net' prefix from functions and structs used by external drivers.
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
In order to avoid confusion between the function and the similarly
named struct.
In preparation for removing the 'net' prefix from dim members.
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Only renaming functions and structs which aren't used by an external code.
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
In preparation for supporting more implementations of the DIM
algorithm, I'm moving what would become common logic to a common
library. Downstream DIM implementations will use the common lib
for their implementation.
Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Exynos SoCs based on CA7/CA15 have 2 timer interfaces: custom Exynos MCT
(Multi Core Timer) and standard ARM Architected Timers.
There are use cases, where both timer interfaces are used simultanously.
One of such examples is using Exynos MCT for the main system timer and
ARM Architected Timers for the KVM and virtualized guests (KVM requires
arch timers).
Exynos Multi-Core Timer driver (exynos_mct) must be however started
before ARM Architected Timers (arch_timer), because they both share some
common hardware blocks (global system counter) and turning on MCT is
needed to get ARM Architected Timer working properly.
To ensure selecting Exynos MCT as the main system timer, increase MCT
timer rating. To ensure proper starting order of both timers during
suspend/resume cycle, increase MCT hotplug priority over ARM Archictected
Timers.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Add a device link between the PWM consumer and the PWM provider. This
enforces the PWM user to get suspended before the PWM provider. It
allows proper synchronization of suspend/resume sequences: the PWM user
is responsible for properly stopping PWM, before the provider gets
suspended: see [1]. Add the device link in:
- of_pwm_get()
- pwm_get()
- devm_*pwm_get() variants
as it requires a reference to the device for the PWM consumer.
[1] https://lkml.org/lkml/2019/2/5/770
Suggested-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
DMA_ATTR_NO_KERNEL_MAPPING is generally implemented by allocating
normal cacheable pages or CMA memory, and then returning the page
pointer as the opaque handle. Lift that code from the xtensa and
generic dma remapping implementations into the generic dma-direct
code so that we don't even call arch_dma_alloc for these allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
IO_PGTABLE_QUIRK_NO_DMA is a bit of a misnomer, since it's really just
an indication of whether or not the page-table walker for the IOMMU is
coherent with the CPU caches. Since cache coherency is more than just a
quirk, replace the flag with its own field in the io_pgtable_cfg
structure.
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Expose some of internal functions that are required for implementation of
customized regulator couplers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Right now regulator core supports only one type of regulators coupling,
the "voltage max-spread" which keeps voltages of coupled regulators in a
given range from each other. A more sophisticated coupling may be required
in practice, one example is the NVIDIA Tegra SoCs which besides the
max-spreading have other restrictions that must be adhered. Introduce API
that allow platforms to provide their own customized coupling algorithms.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
What is the point in surrounding the whole of declarations with
ifdef like this?
#ifdef CONFIG_FOO
int foo(void);
#endif
If CONFIG_FOO is not defined, all callers of foo() will fail
with implicit declaration errors since the top Makefile adds
-Werror-implicit-function-declaration to KBUILD_CFLAGS.
This breaks the build earlier when you are doing something wrong.
That's it.
Anyway, it will fail to link since the definition of foo() is not
compiled.
In summary, these ifdef are unneeded.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Check if we need to allocate uncached memory for a device given the
allocation flags. Switch over the uncached segment check to this helper
to deal with architectures that do not support the dma_cache_sync
operation and thus should not returned cacheable memory for
DMA_ATTR_NON_CONSISTENT allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
The lock protecting the data structure does not need to be an rwlock. The
only read access to the lock is in an error path, and if that's limiting
your scalability, you have bigger performance problems.
Eliminate mlx5_mkey_table in favour of using the xarray directly.
reg_mr_callback must use GFP_ATOMIC for allocating XArray nodes as it may
be called in interrupt context.
This also fixes a minor bug where SRCU locking was being used on the radix
tree read side, when RCU was needed too.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Resolve conflict between d2912cb15b ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer
and fe03d47456 ("Update my email address") which updates Jozsef
Kadlecsik's email.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
After the first call to GetEventLog() on UEFI systems using the TCG2
crypto agile log format, any further log events (other than those
triggered by ExitBootServices()) will be logged in both the main log and
also in the Final Events Log. While the kernel only calls GetEventLog()
immediately before ExitBootServices(), we can't control whether earlier
parts of the boot process have done so. This will result in log entries
that exist in both logs, and so the current approach of simply appending
the Final Event Log to the main log will result in events being
duplicated.
We can avoid this problem by looking at the size of the Final Event Log
just before we call ExitBootServices() and exporting this to the main
kernel. The kernel can then skip over all events that occured before
ExitBootServices() and only append events that were not also logged to
the main log.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reported-by: Joe Richey <joerichey@google.com>
Suggested-by: Joe Richey <joerichey@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
UEFI systems provide a boot services protocol for obtaining the TPM
event log, but this is unusable after ExitBootServices() is called.
Unfortunately ExitBootServices() itself triggers additional TPM events
that then can't be obtained using this protocol. The platform provides a
mechanism for the OS to obtain these events by recording them to a
separate UEFI configuration table which the OS can then map.
Unfortunately this table isn't self describing in terms of providing its
length, so we need to parse the events inside it to figure out how long
it is. Since the table isn't mapped at this point, we need to extend the
length calculation function to be able to map the event as it goes
along.
(Fixes by Bartosz Szczepanek <bsz@semihalf.com>)
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Bartosz Szczepanek <bsz@semihalf.com>
Tested-by: Bartosz Szczepanek <bsz@semihalf.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
We need to calculate the size of crypto agile events in multiple
locations, including in the EFI boot stub. The easiest way to do this is
to put it in a header file as an inline and leave a wrapper to ensure we
don't end up with multiple copies of it embedded in the existing code.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Bartosz Szczepanek <bsz@semihalf.com>
Tested-by: Bartosz Szczepanek <bsz@semihalf.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
The SCHED_DEADLINE scheduling class provides an advanced and formal
model to define tasks requirements that can translate into proper
decisions for both task placements and frequencies selections. Other
classes have a more simplified model based on the POSIX concept of
priorities.
Such a simple priority based model however does not allow to exploit
most advanced features of the Linux scheduler like, for example, driving
frequencies selection via the schedutil cpufreq governor. However, also
for non SCHED_DEADLINE tasks, it's still interesting to define tasks
properties to support scheduler decisions.
Utilization clamping exposes to user-space a new set of per-task
attributes the scheduler can use as hints about the expected/required
utilization for a task. This allows to implement a "proactive" per-task
frequency control policy, a more advanced policy than the current one
based just on "passive" measured task utilization. For example, it's
possible to boost interactive tasks (e.g. to get better performance) or
cap background tasks (e.g. to be more energy/thermal efficient).
Introduce a new API to set utilization clamping values for a specified
task by extending sched_setattr(), a syscall which already allows to
define task specific properties for different scheduling classes. A new
pair of attributes allows to specify a minimum and maximum utilization
the scheduler can consider for a task.
Do that by validating the required clamp values before and then applying
the required changes using _the_ same pattern already in use for
__setscheduler(). This ensures that the task is re-enqueued with the new
clamp values.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-7-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tasks without a user-defined clamp value are considered not clamped
and by default their utilization can have any value in the
[0..SCHED_CAPACITY_SCALE] range.
Tasks with a user-defined clamp value are allowed to request any value
in that range, and the required clamp is unconditionally enforced.
However, a "System Management Software" could be interested in limiting
the range of clamp values allowed for all tasks.
Add a privileged interface to define a system default configuration via:
/proc/sys/kernel/sched_uclamp_util_{min,max}
which works as an unconditional clamp range restriction for all tasks.
With the default configuration, the full SCHED_CAPACITY_SCALE range of
values is allowed for each clamp index. Otherwise, the task-specific
clamp is capped by the corresponding system default value.
Do that by tracking, for each task, the "effective" clamp value and
bucket the task has been refcounted in at enqueue time. This
allows to lazy aggregate "requested" and "system default" values at
enqueue time and simplifies refcounting updates at dequeue time.
The cached bucket ids are used to avoid (relatively) more expensive
integer divisions every time a task is enqueued.
An active flag is used to report when the "effective" value is valid and
thus the task is actually refcounted in the corresponding rq's bucket.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-5-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
