This patch adds 2 APIs, as well as driver operations to support adding
and deleting an IB sub device, which provides part of functionalities
of it's parent.
A sub device has a type; for a sub device with type "SMI", it provides
the smi capability through umad for its parent, meaning uverb is not
supported.
A sub device cannot live without a parent. So when a parent is
released, all it's sub devices are released as well.
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Link: https://lore.kernel.org/r/44253f7508b21eb2caefea3980c2bc072869116c.1718553901.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next:
Patch #1 to #11 to shrink memory consumption for transaction objects:
struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */
struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */
struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */
struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */
struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */
struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */
struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */
struct nft_trans_elem can now be allocated from kmalloc-96 instead of
kmalloc-128 slab.
Series from Florian Westphal. For the record, I have mangled patch #1
to add nft_trans_container_*() and use if for every transaction object.
I have also added BUILD_BUG_ON to ensure struct nft_trans always comes
at the beginning of the container transaction object. And few minor
cleanups, any new bugs are of my own.
Patch #12 simplify check for SCTP GSO in IPVS, from Ismael Luceno.
Patch #13 nf_conncount key length remains in the u32 bound, from Yunjian Wang.
Patch #14 removes unnecessary check for CTA_TIMEOUT_L3PROTO when setting
default conntrack timeouts via nfnetlink_cttimeout API, from
Lin Ma.
Patch #15 updates NFT_SECMARK_CTX_MAXLEN to 4096, SELinux could use
larger secctx names than the existing 256 bytes length.
Patch #16 adds a selftest to exercise nfnetlink_queue listeners leaving
nfnetlink_queue, from Florian Westphal.
Patch #17 increases hitcount from 255 to 65535 in xt_recent, from Phil Sutter.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a protocol spec for tcp_metrics, so that it's accessible via YNL.
Useful at the very least for testing fixes.
In this episode of "10,000 ways to complicate netlink" the metric
nest has defines which are off by 1. iproute2 does:
struct rtattr *m[TCP_METRIC_MAX + 1 + 1];
parse_rtattr_nested(m, TCP_METRIC_MAX + 1, a);
for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
// ...
attr = m[i + 1];
This is too weird to support in YNL, add a new set of defines
with _correct_ values to the official kernel header.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_metrics' header lacks the customary _UAPI in the header guard.
This makes YNL build rules work less seamlessly.
We can easily fix that on YNL side, but this could also be
problematic if we ever needed to create a kernel-only tcp_metrics.h.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the necessary infrastructure to the IIO core to support a new
optional DMABUF based interface.
With this new interface, DMABUF objects (externally created) can be
attached to a IIO buffer, and subsequently used for data transfer.
A userspace application can then use this interface to share DMABUF
objects between several interfaces, allowing it to transfer data in a
zero-copy fashion, for instance between IIO and the USB stack.
The userspace application can also memory-map the DMABUF objects, and
access the sample data directly. The advantage of doing this vs. the
read() interface is that it avoids an extra copy of the data between the
kernel and userspace. This is particularly userful for high-speed
devices which produce several megabytes or even gigabytes of data per
second.
As part of the interface, 3 new IOCTLs have been added:
IIO_BUFFER_DMABUF_ATTACH_IOCTL(int fd):
Attach the DMABUF object identified by the given file descriptor to the
buffer.
IIO_BUFFER_DMABUF_DETACH_IOCTL(int fd):
Detach the DMABUF object identified by the given file descriptor from
the buffer. Note that closing the IIO buffer's file descriptor will
automatically detach all previously attached DMABUF objects.
IIO_BUFFER_DMABUF_ENQUEUE_IOCTL(struct iio_dmabuf *):
Request a data transfer to/from the given DMABUF object. Its file
descriptor, as well as the transfer size and flags are provided in the
"iio_dmabuf" structure.
These three IOCTLs have to be performed on the IIO buffer's file
descriptor, obtained using the IIO_BUFFER_GET_FD_IOCTL() ioctl.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Co-developed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240620122726.41232-4-paul@crapouillou.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
statmount() can export arbitrary strings, so utilize the __spare1 slot
for a mnt_opts string pointer, and then support asking for and setting
the mount options during statmount(). This calls into the helper for
showing mount options, which already uses a seq_file, so fits in nicely
with our existing mechanism for exporting strings via statmount().
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/3aa6bf8bd5d0a21df9ebd63813af8ab532c18276.1719257716.git.josef@toxicpanda.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
[brauner: only call sb->s_op->show_options()]
Signed-off-by: Christian Brauner <brauner@kernel.org>
CMIS compliant modules such as QSFP-DD might be running a firmware that
can be updated in a vendor-neutral way by exchanging messages between
the host and the module as described in section 7.3.1 of revision 5.2 of
the CMIS standard.
Add a pair of new ethtool messages that allow:
* User space to trigger firmware update of transceiver modules
* The kernel to notify user space about the progress of the process
The user interface is designed to be asynchronous in order to avoid
RTNL being held for too long and to allow several modules to be
updated simultaneously. The interface is designed with CMIS compliant
modules in mind, but kept generic enough to accommodate future use
cases, if these arise.
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
util-linux is about to implement listmount() and statmount() support.
Karel requested the ability to scan the mount table in backwards order
because that's what libmount currently does in order to get the latest
mount first. We currently don't support this in listmount(). Add a new
LISTMOUNT_REVERSE flag to allow listing mounts in reverse order. For
example, listing all child mounts of /sys without LISTMOUNT_REVERSE
gives:
/sys/kernel/security @ mnt_id: 4294968369
/sys/fs/cgroup @ mnt_id: 4294968370
/sys/firmware/efi/efivars @ mnt_id: 4294968371
/sys/fs/bpf @ mnt_id: 4294968372
/sys/kernel/tracing @ mnt_id: 4294968373
/sys/kernel/debug @ mnt_id: 4294968374
/sys/fs/fuse/connections @ mnt_id: 4294968375
/sys/kernel/config @ mnt_id: 4294968376
whereas with LISTMOUNT_REVERSE it gives:
/sys/kernel/config @ mnt_id: 4294968376
/sys/fs/fuse/connections @ mnt_id: 4294968375
/sys/kernel/debug @ mnt_id: 4294968374
/sys/kernel/tracing @ mnt_id: 4294968373
/sys/fs/bpf @ mnt_id: 4294968372
/sys/firmware/efi/efivars @ mnt_id: 4294968371
/sys/fs/cgroup @ mnt_id: 4294968370
/sys/kernel/security @ mnt_id: 4294968369
Link: https://lore.kernel.org/r/20240607-vfs-listmount-reverse-v1-4-7877a2bfa5e5@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
UAPI Changes:
- New uapi adding OA functionality to Xe (Ashutosh)
Cross-subsystem Changes:
- devcoredump: Add dev_coredumpm_timeout (Jose)
Driver Changes:
- More SRIOV preparation, including GuC communication improvements (Michal)
- Kconfig update: do not select ACPI_BUTTON (Jani)
- Rework GPU page fault handling (Brost)
- Forcewake clean-up and fixes (Himal, Michal)
- Drop EXEC_QUEUE_FLAG_BANNED (Brost)
- Xe/Xe2 Workarounds fixes and additions (Tejas, Akshata, Sai, Vinay)
- Xe devcoredump changes (Jose)
- Tracing cleanup and add mmio tracing (RK)
- Add BMG PCI IDs (Roper)
- Scheduler fixes and improvements (Brost)
- Some overal driver clean-up around headers and print macros (Michal)
- Rename xe_exec_queue::compute to xe_exec_queue::lr (Francois)
- Improve RTP rules to allow easier 'OR' conditions in WA declaration (Lucas)
- Use ttm_uncached for BO with NEEDS_UC flag (Michal)
- Other OA related work and fixes (Ashutosh, Michal, Jose)
- Simplify locking in new_vma (Brost)
- Remove xe_irq_shutdown (Ilia)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ZnyW9RdC_aWSla_q@intel.com
Need to sync some header include that propagated through
drm-intel-next.
v2: After some changes in drm/drm-next
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Add the ability to send out RFC-3948 NAT keepalives from the xfrm stack.
To use, Userspace sets an XFRM_NAT_KEEPALIVE_INTERVAL integer property when
creating XFRM outbound states which denotes the number of seconds between
keepalive messages.
Keepalive messages are sent from a per net delayed work which iterates over
the xfrm states. The logic is guarded by the xfrm state spinlock due to the
xfrm state walk iterator.
Possible future enhancements:
- Adding counters to keep track of sent keepalives.
- deduplicate NAT keepalives between states sharing the same nat keepalive
parameters.
- provisioning hardware offloads for devices capable of implementing this.
- revise xfrm state list to use an rcu list in order to avoid running this
under spinlock.
Suggested-by: Paul Wouters <paul.wouters@aiven.io>
Tested-by: Paul Wouters <paul.wouters@aiven.io>
Tested-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
The NetDIM library, currently leveraged by an array of NICs, delivers
excellent acceleration benefits. Nevertheless, NICs vary significantly
in their dim profile list prerequisites.
Specifically, virtio-net backends may present diverse sw or hw device
implementation, making a one-size-fits-all parameter list impractical.
On Alibaba Cloud, the virtio DPU's performance under the default DIM
profile falls short of expectations, partly due to a mismatch in
parameter configuration.
I also noticed that ice/idpf/ena and other NICs have customized
profilelist or placed some restrictions on dim capabilities.
Motivated by this, I tried adding new params for "ethtool -C" that provides
a per-device control to modify and access a device's interrupt parameters.
Usage
========
The target NIC is named ethx.
Assume that ethx only declares support for rx profile setting
(with DIM_PROFILE_RX flag set in profile_flags) and supports modification
of usec and pkt fields.
1. Query the currently customized list of the device
$ ethtool -c ethx
...
rx-profile:
{.usec = 1, .pkts = 256, .comps = n/a,},
{.usec = 8, .pkts = 256, .comps = n/a,},
{.usec = 64, .pkts = 256, .comps = n/a,},
{.usec = 128, .pkts = 256, .comps = n/a,},
{.usec = 256, .pkts = 256, .comps = n/a,}
tx-profile: n/a
2. Tune
$ ethtool -C ethx rx-profile 1,1,n_2,n,n_3,3,n_4,4,n_n,5,n
"n" means do not modify this field.
$ ethtool -c ethx
...
rx-profile:
{.usec = 1, .pkts = 1, .comps = n/a,},
{.usec = 2, .pkts = 256, .comps = n/a,},
{.usec = 3, .pkts = 3, .comps = n/a,},
{.usec = 4, .pkts = 4, .comps = n/a,},
{.usec = 256, .pkts = 5, .comps = n/a,}
tx-profile: n/a
3. Hint
If the device does not support some type of customized dim profiles,
the corresponding "n/a" will display.
If the "n/a" field is being modified, -EOPNOTSUPP will be reported.
Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240621101353.107425-4-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add ioctl()s to translate pids between pid namespaces.
LXCFS is a tiny fuse filesystem used to virtualize various aspects of
procfs. LXCFS is run on the host. The files and directories it creates
can be bind-mounted by e.g. a container at startup and mounted over the
various procfs files the container wishes to have virtualized. When e.g.
a read request for uptime is received, LXCFS will receive the pid of the
reader. In order to virtualize the corresponding read, LXCFS needs to
know the pid of the init process of the reader's pid namespace. In order
to do this, LXCFS first needs to fork() two helper processes. The first
helper process setns() to the readers pid namespace. The second helper
process is needed to create a process that is a proper member of the pid
namespace. The second helper process then creates a ucred message with
ucred.pid set to 1 and sends it back to LXCFS. The kernel will translate
the ucred.pid field to the corresponding pid number in LXCFS's pid
namespace. This way LXCFS can learn the init pid number of the reader's
pid namespace and can go on to virtualize. Since these two forks() are
costly LXCFS maintains an init pid cache that caches a given pid for a
fixed amount of time. The cache is pruned during new read requests.
However, even with the cache the hit of the two forks() is singificant
when a very large number of containers are running. With this simple
patch we add an ns ioctl that let's a caller retrieve the init pid nr of
a pid namespace through its pid namespace fd. This significantly
improves performance with a very simple change.
Support translation of pids and tgids. Other concepts can be added but
there are no obvious users for this right now.
To protect against races pidfds can be used to check whether the process
is still valid. If needed, this can also be extended to work on pidfds
directly.
Link: https://lore.kernel.org/r/20240619-work-ns_ioctl-v1-1-7c0097e6bb6b@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.
This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc8 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.
Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.
Cc: stable@vger.kernel.org
Fixes: 48166e6ea4 ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
drm-misc-next for 6.10:
UAPI Changes:
Cross-subsystem Changes:
- dma-buf: Warn when reserving 0 fence slots, internal API
enhancements for heaps
Core Changes:
Driver Changes:
- atmel-hlcdc: Support XLCDC in sam9x7
- msm: Validate registers XML description against schema in CI
- v3d: Fix build warning
- bridges:
- analogix_dp: Various improvements
- panels:
- New panel: WL-355608-A8
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240606-vivid-amphibian-jackrabbit-40b1d1@houat
drm-misc-next for 6.11:
UAPI Changes:
- Deprecate DRM date and return a 0 date in DRM_IOCTL_VERSION
Core Changes:
- connector: Create a set of helpers to help with HDMI support
- fbdev: Create memory manager optimized fbdev emulation
- panic: Allow to select fonts, improve drm_fb_dma_get_scanout_buffer
Driver Changes:
- Remove driver owner assignments
- Allow more drivers to compile with COMPILE_TEST
- Conversions to drm_edid
- ivpu: hardware scheduler support, profiling support, improvements
to the platform support layer
- mgag200: general reworks and improvements
- nouveau: Add NVreg_RegistryDwords command line option
- rockchip: Conversion to the hdmi helpers
- sun4i: Conversion to the hdmi helpers
- vc4: Conversion to the hdmi helpers
- v3d: Perf counters improvements
- zynqmp: IRQ and debugfs improvements
- bridge:
- Remove redundant checks on bridge->encoder
- panels:
- Switch panels from register table initialization to proper code
- Now that the panel code tracks the panel state, remove every
ad-hoc implementation in the panel drivers
- New panels: Lincoln Tech Sol LCD185-101CT, Microtips Technology
13-101HIEBCAF0-C, Microtips Technology MF-103HIEB0GA0, BOE
nv110wum-l60, IVO t109nw41
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240530-hilarious-flat-magpie-5fa186@houat
An atomic write is a write issued with torn-write protection, meaning
that for a power failure or any other hardware failure, all or none of the
data from the write will be stored, but never a mix of old and new data.
Userspace may add flag RWF_ATOMIC to pwritev2() to indicate that the
write is to be issued with torn-write prevention, according to special
alignment and length rules.
For any syscall interface utilizing struct iocb, add IOCB_ATOMIC for
iocb->ki_flags field to indicate the same.
A call to statx will give the relevant atomic write info for a file:
- atomic_write_unit_min
- atomic_write_unit_max
- atomic_write_segments_max
Both min and max values must be a power-of-2.
Applications can avail of atomic write feature by ensuring that the total
length of a write is a power-of-2 in size and also sized between
atomic_write_unit_min and atomic_write_unit_max, inclusive. Applications
must ensure that the write is at a naturally-aligned offset in the file
wrt the total write length. The value in atomic_write_segments_max
indicates the upper limit for IOV_ITER iovcnt.
Add file mode flag FMODE_CAN_ATOMIC_WRITE, so files which do not have the
flag set will have RWF_ATOMIC rejected and not just ignored.
Add a type argument to kiocb_set_rw_flags() to allows reads which have
RWF_ATOMIC set to be rejected.
Helper function generic_atomic_write_valid() can be used by FSes to verify
compliant writes. There we check for iov_iter type is for ubuf, which
implies iovcnt==1 for pwritev2(), which is an initial restriction for
atomic_write_segments_max. Initially the only user will be bdev file
operations write handler. We will rely on the block BIO submission path to
ensure write sizes are compliant for the bdev, so we don't need to check
atomic writes sizes yet.
Signed-off-by: Prasad Singamsetty <prasad.singamsetty@oracle.com>
jpg: merge into single patch and much rewrite
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20240620125359.2684798-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
IORING_OP_LISTEN provides the semantic of listen(2) via io_uring. While
this is an essentially synchronous system call, the main point is to
enable a network path to execute fully with io_uring registered and
descriptorless files.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240614163047.31581-4-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
IORING_OP_BIND provides the semantic of bind(2) via io_uring. While
this is an essentially synchronous system call, the main point is to
enable a network path to execute fully with io_uring registered and
descriptorless files.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240614163047.31581-3-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Implement a new scheduler class sched_ext (SCX), which allows scheduling
policies to be implemented as BPF programs to achieve the following:
1. Ease of experimentation and exploration: Enabling rapid iteration of new
scheduling policies.
2. Customization: Building application-specific schedulers which implement
policies that are not applicable to general-purpose schedulers.
3. Rapid scheduler deployments: Non-disruptive swap outs of scheduling
policies in production environments.
sched_ext leverages BPF’s struct_ops feature to define a structure which
exports function callbacks and flags to BPF programs that wish to implement
scheduling policies. The struct_ops structure exported by sched_ext is
struct sched_ext_ops, and is conceptually similar to struct sched_class. The
role of sched_ext is to map the complex sched_class callbacks to the more
simple and ergonomic struct sched_ext_ops callbacks.
For more detailed discussion on the motivations and overview, please refer
to the cover letter.
Later patches will also add several example schedulers and documentation.
This patch implements the minimum core framework to enable implementation of
BPF schedulers. Subsequent patches will gradually add functionalities
including safety guarantee mechanisms, nohz and cgroup support.
include/linux/sched/ext.h defines struct sched_ext_ops. With the comment on
top, each operation should be self-explanatory. The followings are worth
noting:
- Both "sched_ext" and its shorthand "scx" are used. If the identifier
already has "sched" in it, "ext" is used; otherwise, "scx".
- In sched_ext_ops, only .name is mandatory. Every operation is optional and
if omitted a simple but functional default behavior is provided.
- A new policy constant SCHED_EXT is added and a task can select sched_ext
by invoking sched_setscheduler(2) with the new policy constant. However,
if the BPF scheduler is not loaded, SCHED_EXT is the same as SCHED_NORMAL
and the task is scheduled by CFS. When the BPF scheduler is loaded, all
tasks which have the SCHED_EXT policy are switched to sched_ext.
- To bridge the workflow imbalance between the scheduler core and
sched_ext_ops callbacks, sched_ext uses simple FIFOs called dispatch
queues (dsq's). By default, there is one global dsq (SCX_DSQ_GLOBAL), and
one local per-CPU dsq (SCX_DSQ_LOCAL). SCX_DSQ_GLOBAL is provided for
convenience and need not be used by a scheduler that doesn't require it.
SCX_DSQ_LOCAL is the per-CPU FIFO that sched_ext pulls from when putting
the next task on the CPU. The BPF scheduler can manage an arbitrary number
of dsq's using scx_bpf_create_dsq() and scx_bpf_destroy_dsq().
- sched_ext guarantees system integrity no matter what the BPF scheduler
does. To enable this, each task's ownership is tracked through
p->scx.ops_state and all tasks are put on scx_tasks list. The disable path
can always recover and revert all tasks back to CFS. See p->scx.ops_state
and scx_tasks.
- A task is not tied to its rq while enqueued. This decouples CPU selection
from queueing and allows sharing a scheduling queue across an arbitrary
subset of CPUs. This adds some complexities as a task may need to be
bounced between rq's right before it starts executing. See
dispatch_to_local_dsq() and move_task_to_local_dsq().
- One complication that arises from the above weak association between task
and rq is that synchronizing with dequeue() gets complicated as dequeue()
may happen anytime while the task is enqueued and the dispatch path might
need to release the rq lock to transfer the task. Solving this requires a
bit of complexity. See the logic around p->scx.sticky_cpu and
p->scx.ops_qseq.
- Both enable and disable paths are a bit complicated. The enable path
switches all tasks without blocking to avoid issues which can arise from
partially switched states (e.g. the switching task itself being starved).
The disable path can't trust the BPF scheduler at all, so it also has to
guarantee forward progress without blocking. See scx_ops_enable() and
scx_ops_disable_workfn().
- When sched_ext is disabled, static_branches are used to shut down the
entry points from hot paths.
v7: - scx_ops_bypass() was incorrectly and unnecessarily trying to grab
scx_ops_enable_mutex which can lead to deadlocks in the disable path.
Fixed.
- Fixed TASK_DEAD handling bug in scx_ops_enable() path which could lead
to use-after-free.
- Consolidated per-cpu variable usages and other cleanups.
v6: - SCX_NR_ONLINE_OPS replaced with SCX_OPI_*_BEGIN/END so that multiple
groups can be expressed. Later CPU hotplug operations are put into
their own group.
- SCX_OPS_DISABLING state is replaced with the new bypass mechanism
which allows temporarily putting the system into simple FIFO
scheduling mode bypassing the BPF scheduler. In addition to the shut
down path, this will also be used to isolate the BPF scheduler across
PM events. Enabling and disabling the bypass mode requires iterating
all runnable tasks. rq->scx.runnable_list addition is moved from the
later watchdog patch.
- ops.prep_enable() is replaced with ops.init_task() and
ops.enable/disable() are now called whenever the task enters and
leaves sched_ext instead of when the task becomes schedulable on
sched_ext and stops being so. A new operation - ops.exit_task() - is
called when the task stops being schedulable on sched_ext.
- scx_bpf_dispatch() can now be called from ops.select_cpu() too. This
removes the need for communicating local dispatch decision made by
ops.select_cpu() to ops.enqueue() via per-task storage.
SCX_KF_SELECT_CPU is added to support the change.
- SCX_TASK_ENQ_LOCAL which told the BPF scheudler that
scx_select_cpu_dfl() wants the task to be dispatched to the local DSQ
was removed. Instead, scx_bpf_select_cpu_dfl() now dispatches directly
if it finds a suitable idle CPU. If such behavior is not desired,
users can use scx_bpf_select_cpu_dfl() which returns the verdict in a
bool out param.
- scx_select_cpu_dfl() was mishandling WAKE_SYNC and could end up
queueing many tasks on a local DSQ which makes tasks to execute in
order while other CPUs stay idle which made some hackbench numbers
really bad. Fixed.
- The current state of sched_ext can now be monitored through files
under /sys/sched_ext instead of /sys/kernel/debug/sched/ext. This is
to enable monitoring on kernels which don't enable debugfs.
- sched_ext wasn't telling BPF that ops.dispatch()'s @prev argument may
be NULL and a BPF scheduler which derefs the pointer without checking
could crash the kernel. Tell BPF. This is currently a bit ugly. A
better way to annotate this is expected in the future.
- scx_exit_info updated to carry pointers to message buffers instead of
embedding them directly. This decouples buffer sizes from API so that
they can be changed without breaking compatibility.
- exit_code added to scx_exit_info. This is used to indicate different
exit conditions on non-error exits and will be used to handle e.g. CPU
hotplugs.
- The patch "sched_ext: Allow BPF schedulers to switch all eligible
tasks into sched_ext" is folded in and the interface is changed so
that partial switching is indicated with a new ops flag
%SCX_OPS_SWITCH_PARTIAL. This makes scx_bpf_switch_all() unnecessasry
and in turn SCX_KF_INIT. ops.init() is now called with
SCX_KF_SLEEPABLE.
- Code reorganized so that only the parts necessary to integrate with
the rest of the kernel are in the header files.
- Changes to reflect the BPF and other kernel changes including the
addition of bpf_sched_ext_ops.cfi_stubs.
v5: - To accommodate 32bit configs, p->scx.ops_state is now atomic_long_t
instead of atomic64_t and scx_dsp_buf_ent.qseq which uses
load_acquire/store_release is now unsigned long instead of u64.
- Fix the bug where bpf_scx_btf_struct_access() was allowing write
access to arbitrary fields.
- Distinguish kfuncs which can be called from any sched_ext ops and from
anywhere. e.g. scx_bpf_pick_idle_cpu() can now be called only from
sched_ext ops.
- Rename "type" to "kind" in scx_exit_info to make it easier to use on
languages in which "type" is a reserved keyword.
- Since cff9b2332a ("kernel/sched: Modify initial boot task idle
setup"), PF_IDLE is not set on idle tasks which haven't been online
yet which made scx_task_iter_next_filtered() include those idle tasks
in iterations leading to oopses. Update scx_task_iter_next_filtered()
to directly test p->sched_class against idle_sched_class instead of
using is_idle_task() which tests PF_IDLE.
- Other updates to match upstream changes such as adding const to
set_cpumask() param and renaming check_preempt_curr() to
wakeup_preempt().
v4: - SCHED_CHANGE_BLOCK replaced with the previous
sched_deq_and_put_task()/sched_enq_and_set_tsak() pair. This is
because upstream is adaopting a different generic cleanup mechanism.
Once that lands, the code will be adapted accordingly.
- task_on_scx() used to test whether a task should be switched into SCX,
which is confusing. Renamed to task_should_scx(). task_on_scx() now
tests whether a task is currently on SCX.
- scx_has_idle_cpus is barely used anymore and replaced with direct
check on the idle cpumask.
- SCX_PICK_IDLE_CORE added and scx_pick_idle_cpu() improved to prefer
fully idle cores.
- ops.enable() now sees up-to-date p->scx.weight value.
- ttwu_queue path is disabled for tasks on SCX to avoid confusing BPF
schedulers expecting ->select_cpu() call.
- Use cpu_smt_mask() instead of topology_sibling_cpumask() like the rest
of the scheduler.
v3: - ops.set_weight() added to allow BPF schedulers to track weight changes
without polling p->scx.weight.
- move_task_to_local_dsq() was losing SCX-specific enq_flags when
enqueueing the task on the target dsq because it goes through
activate_task() which loses the upper 32bit of the flags. Carry the
flags through rq->scx.extra_enq_flags.
- scx_bpf_dispatch(), scx_bpf_pick_idle_cpu(), scx_bpf_task_running()
and scx_bpf_task_cpu() now use the new KF_RCU instead of
KF_TRUSTED_ARGS to make it easier for BPF schedulers to call them.
- The kfunc helper access control mechanism implemented through
sched_ext_entity.kf_mask is improved. Now SCX_CALL_OP*() is always
used when invoking scx_ops operations.
v2: - balance_scx_on_up() is dropped. Instead, on UP, balance_scx() is
called from put_prev_taks_scx() and pick_next_task_scx() as necessary.
To determine whether balance_scx() should be called from
put_prev_task_scx(), SCX_TASK_DEQD_FOR_SLEEP flag is added. See the
comment in put_prev_task_scx() for details.
- sched_deq_and_put_task() / sched_enq_and_set_task() sequences replaced
with SCHED_CHANGE_BLOCK().
- Unused all_dsqs list removed. This was a left-over from previous
iterations.
- p->scx.kf_mask is added to track and enforce which kfunc helpers are
allowed. Also, init/exit sequences are updated to make some kfuncs
always safe to call regardless of the current BPF scheduler state.
Combined, this should make all the kfuncs safe.
- BPF now supports sleepable struct_ops operations. Hacky workaround
removed and operations and kfunc helpers are tagged appropriately.
- BPF now supports bitmask / cpumask helpers. scx_bpf_get_idle_cpumask()
and friends are added so that BPF schedulers can use the idle masks
with the generic helpers. This replaces the hacky kfunc helpers added
by a separate patch in V1.
- CONFIG_SCHED_CLASS_EXT can no longer be enabled if SCHED_CORE is
enabled. This restriction will be removed by a later patch which adds
core-sched support.
- Add MAINTAINERS entries and other misc changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Co-authored-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
Implement query for properties of OA units present on a device.
v2: Clean up reserved/pad fields (Umesh)
Follow the same scheme as other query structs
v3: Skip reporting reserved engines attached to OA units
v4: Expose oa_buf_size via DRM_XE_PERF_IOCTL_INFO (Umesh)
v5: Don't expose capabilities as OR of properties (Umesh)
v6: Add extensions to query output structs: drm_xe_oa_unit,
drm_xe_query_oa_units and drm_xe_oa_stream_info
v7: Change oa_units[] array to __u64 type
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-13-ashutosh.dixit@intel.com
Implement the OA stream read file_operation. Both blocking and non-blocking
reads are supported. As part of read system call, the read copies OA perf
data from the OA buffer to the user buffer, after appending packet headers
for status and data packets.
v2: Drop OA report headers, implement DRM_XE_PERF_IOCTL_STATUS (Umesh)
v3: Introduce 'struct drm_xe_oa_stream_status'
v4: Define oa_status register bitfields (Umesh)
v5: Add extensions to 'struct drm_xe_oa_stream_status'
v6: Minor cleanup, eliminate report32 variable
v7: Use -EIO to signal to userspace to read OASTATUS using
DRM_XE_PERF_IOCTL_STATUS, change previous sites returning -EIO to
return -EINVAL
Make drm_xe_oa_stream_status bits contiguous (Jose, Umesh)
rmw oa_status bits (Umesh)
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-10-ashutosh.dixit@intel.com
The OA stream open perf op returns an fd with its own file_operations for
the newly initialized OA stream. These file_operations allow userspace to
enable or disable the stream, as well as apply a different metric
configuration for the OA stream. Userspace can also poll for data
availability. OA stream initialization is completed in this commit by
enabling the OA stream. When sampling is enabled this starts a hrtimer
which periodically checks for data availablility.
v2: Use stream properties for stream reconfiguration with
DRM_XE_PERF_IOCTL_CONFIG
v3: Hold runtime_pm reference across oa buffer alloc/free
v4: Fix 32 bit build
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-9-ashutosh.dixit@intel.com
Properties for OA streams are specified by user space, when the stream is
opened, as a chain of drm_xe_ext_set_property struct's. Parse and validate
these stream properties.
v2: Remove struct drm_xe_oa_open_param (Harish Chegondi)
Drop DRM_XE_OA_PROPERTY_POLL_OA_PERIOD_US (Umesh)
Eliminate comparison with xe_oa_max_sample_rate (Umesh)
Drop 'struct drm_xe_oa_record_header' (Umesh)
v3: s/DRM_XE_OA_PROPERTY_OA_EXPONENT/ \
DRM_XE_OA_PROPERTY_OA_PERIOD_EXPONENT/ (Jose)
v4: Fix 32 bit build
v5: Add non-static function kernel doc (Michal)
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-7-ashutosh.dixit@intel.com
Introduce add/remove config perf ops for OA. OA configurations consist of a
set of event/counter select register address/value pairs. The add_config
perf op validates and stores such configurations and also exposes them in
the metrics sysfs. These configurations will be programmed to OA unit HW
when an OA stream using a configuration is opened. The OA stream can also
switch to other stored configurations.
v2: Start config id's from 1 and other minor review comments (Umesh)
v3: Add 32 bit build
v4: Add kernel doc for non-static functions (Michal)
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-6-ashutosh.dixit@intel.com
In Xe, the plan is to support multiple types of perf counter streams (OA is
only one type of these streams). Rather than introduce NxM ioctls for
these (N perf streams with M ioctl's per perf stream), we decide to
multiplex these (N different stream types and the M ops for each of these
stream types) through a single PERF ioctl. This multiplexing is the purpose
of the PERF layer.
In addition to PERF DRM ioctl's, another set of ioctl's on the PERF fd are
defined. These are expected to be common to different PERF stream types and
therefore defined at the PERF layer itself.
v2: Add param_size to 'struct drm_xe_perf_param' (Umesh)
v3: Rename 'enum drm_xe_perf_ops' to
'enum drm_xe_perf_ioctls' (Guy Zadicario)
Add DRM_ prefix to ioctl names to indicate uapi names
v4: Add 'enum drm_xe_perf_op' previously missed out (Guy Zadicario)
v5: Squash the ops and PERF layer patches into a single patch (Umesh)
Remove param_size from struct 'drm_xe_perf_param' (Umesh)
v6: Add DRM_XE_PERF_IOCTL_STATUS
v7: Add DRM_XE_PERF_IOCTL_INFO
v8: Fix Copyright years, fix DRM_XE_PERF_TYPE_MAX, move '#include
"xe_perf.h"' to xe_perf.c, add kernel doc (Michal)
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Guy Zadicario <gzadicario@habana.ai>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240618014609.3233427-2-ashutosh.dixit@intel.com
