If delayacct is disabled, then delayacct_is_task_waiting_on_io()
always returns false, which causes the statistical value to be
wrong. Perhaps tsk->in_iowait is better.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The broadcast device is switched to oneshot mode when the system switches
to oneshot mode. If a broadcast clock event device is registered after the
system switched to oneshot mode, it will stay in periodic mode forever.
Ensure that a late registered device which is selected as broadcast device
is initialized in oneshot mode when the system already uses oneshot mode.
[ tglx: Massage changelog ]
Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210331083318.21794-1-jindong.yue@nxp.com
The current sched_slice() seems to have issues; there's two possible
things that could be improved:
- the 'nr_running' used for __sched_period() is daft when cgroups are
considered. Using the RQ wide h_nr_running seems like a much more
consistent number.
- (esp) cgroups can slice it real fine, which makes for easy
over-scheduling, ensure min_gran is what the name says.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.611897312@infradead.org
The ability to enable/disable NUMA balancing is not a debugging feature
and should not depend on CONFIG_SCHED_DEBUG. For example, machines within
a HPC cluster may disable NUMA balancing temporarily for some jobs and
re-enable it for other jobs without needing to reboot.
This patch removes the dependency on CONFIG_SCHED_DEBUG for
kernel.numa_balancing sysctl. The other numa balancing related sysctls
are left as-is because if they need to be tuned then it is more likely
that NUMA balancing needs to be fixed instead.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210324133916.GQ15768@suse.de
Use the new cpu_dying() state to simplify and fix the balance_push()
vs CPU hotplug rollback state.
Specifically, we currently rely on notifiers sched_cpu_dying() /
sched_cpu_activate() to terminate balance_push, however if the
cpu_down() fails when we're past sched_cpu_deactivate(), it should
terminate balance_push at that point and not wait until we hit
sched_cpu_activate().
Similarly, when cpu_up() fails and we're going back down, balance_push
should be active, where it currently is not.
So instead, make sure balance_push is enabled below SCHED_AP_ACTIVE
(when !cpu_active()), and gate it's utility with cpu_dying().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/YHgAYef83VQhKdC2@hirez.programming.kicks-ass.net
Adds bit perf_event_attr::sigtrap, which can be set to cause events to
send SIGTRAP (with si_code TRAP_PERF) to the task where the event
occurred. The primary motivation is to support synchronous signals on
perf events in the task where an event (such as breakpoints) triggered.
To distinguish perf events based on the event type, the type is set in
si_errno. For events that are associated with an address, si_addr is
copied from perf_sample_data.
The new field perf_event_attr::sig_data is copied to si_perf, which
allows user space to disambiguate which event (of the same type)
triggered the signal. For example, user space could encode the relevant
information it cares about in sig_data.
We note that the choice of an opaque u64 provides the simplest and most
flexible option. Alternatives where a reference to some user space data
is passed back suffer from the problem that modification of referenced
data (be it the event fd, or the perf_event_attr) can race with the
signal being delivered (of course, the same caveat applies if user space
decides to store a pointer in sig_data, but the ABI explicitly avoids
prescribing such a design).
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/lkml/YBv3rAT566k+6zjg@hirez.programming.kicks-ass.net/
Adds bit perf_event_attr::remove_on_exec, to support removing an event
from a task on exec.
This option supports the case where an event is supposed to be
process-wide only, and should not propagate beyond exec, to limit
monitoring to the original process image only.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210408103605.1676875-5-elver@google.com
Adds bit perf_event_attr::inherit_thread, to restricting inheriting
events only if the child was cloned with CLONE_THREAD.
This option supports the case where an event is supposed to be
process-wide only (including subthreads), but should not propagate
beyond the current process's shared environment.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/YBvj6eJR%2FDY2TsEB@hirez.programming.kicks-ass.net/
Make perf_event_exit_event() more robust, such that we can use it from
other contexts. Specifically the up and coming remove_on_exec.
For this to work we need to address a few issues. Remove_on_exec will
not destroy the entire context, so we cannot rely on TASK_TOMBSTONE to
disable event_function_call() and we thus have to use
perf_remove_from_context().
When using perf_remove_from_context(), there's two races to consider.
The first is against close(), where we can have concurrent tear-down
of the event. The second is against child_list iteration, which should
not find a half baked event.
To address this, teach perf_remove_from_context() to special case
!ctx->is_active and about DETACH_CHILD.
[ elver@google.com: fix racing parent/child exit in sync_child_event(). ]
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210408103605.1676875-2-elver@google.com
Currently, we start allocating AUX pages half the size of the total
requested AUX buffer size, ignoring the attr.aux_watermark setting. This,
in turn, makes intel_pt driver disregard the watermark also, as it uses
page order for its SG (ToPA) configuration.
Now, this can be fixed in the intel_pt PMU driver, but seeing as it's the
only one currently making use of high order allocations, there is no
reason not to fix the allocator instead. This way, any other driver
wishing to add this support would not have to worry about this.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210414154955.49603-2-alexander.shishkin@linux.intel.com
receive_fd_replace shares almost no code with the general case, so split
it out. Also remove the "Bump the sock usage counts" comment from
both copies, as that is now what __receive_sock actually does.
[AV: ... and make the only user of receive_fd_replace() choose between
it and receive_fd() according to what userland had passed to it in
flags]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The func_repeats event shows the output of the function tracer followed by
a count of the number of repeats the previous function had made, as well
as the timestamp of the last function that was repeated.
The printing of the function should be the same as is for the function it
is displaying. Reuse the code in trace_fn_trace() by making a helper
function print_fn_trace() and use it for trace_func_repeats_print().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the option is activated the function tracing record gets
consolidated in the cases when a single function is called number
of times consecutively. Instead of having an identical record for
each call of the function we will record only the first call
following by event showing the number of repeats.
Link: https://lkml.kernel.org/r/20210415181854.147448-7-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently the logic for dealing with the options for function tracing
has two different implementations. One is used when we set the flags
(in "static int func_set_flag()") and another used when we initialize
the tracer (in "static int function_trace_init()"). Those two
implementations are meant to do essentially the same thing and they
are both not very convenient for adding new options. In this patch
we add a helper function that provides a single implementation of
the logic for dealing with the options and we make it such that new
options can be easily added.
Link: https://lkml.kernel.org/r/20210415181854.147448-6-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The field is used to keep track of the consecutive (on the same CPU) calls
of a single function. This information is needed in order to consolidate
the function tracing record in the cases when a single function is called
number of times.
Link: https://lkml.kernel.org/r/20210415181854.147448-4-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The event aims to consolidate the function tracing record in the cases
when a single function is called number of times consecutively.
while (cond)
do_func();
This may happen in various scenarios (busy waiting for example).
The new ftrace event can be used to show repeated function events with
a single event and save space on the ring buffer
Link: https://lkml.kernel.org/r/20210415181854.147448-3-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The part of the code that prints the time of the trace record in
"int trace_print_context()" gets extracted in a static function. This
is done as a preparation for a following patch, in which we will define
a new ftrace event called "func_repeats". The new static method,
defined here, will be used by this new event to print the time of the
last repeat of a function that is consecutively called number of times.
Link: https://lkml.kernel.org/r/20210415181854.147448-2-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The idea for this originates from the real time tree to make signal
delivery for realtime applications more efficient. In quite some of these
application scenarios a control tasks signals workers to start their
computations. There is usually only one signal per worker on flight. This
works nicely as long as the kmem cache allocations do not hit the slow path
and cause latencies.
To cure this an optimistic caching was introduced (limited to RT tasks)
which allows a task to cache a single sigqueue in a pointer in task_struct
instead of handing it back to the kmem cache after consuming a signal. When
the next signal is sent to the task then the cached sigqueue is used
instead of allocating a new one. This solved the problem for this set of
application scenarios nicely.
The task cache is not preallocated so the first signal sent to a task goes
always to the cache allocator. The cached sigqueue stays around until the
task exits and is freed when task::sighand is dropped.
After posting this solution for mainline the discussion came up whether
this would be useful in general and should not be limited to realtime
tasks: https://lore.kernel.org/r/m11rcu7nbr.fsf@fess.ebiederm.org
One concern leading to the original limitation was to avoid a large amount
of pointlessly cached sigqueues in alive tasks. The other concern was
vs. RLIMIT_SIGPENDING as these cached sigqueues are not accounted for.
The accounting problem is real, but on the other hand slightly academic.
After gathering some statistics it turned out that after boot of a regular
distro install there are less than 10 sigqueues cached in ~1500 tasks.
In case of a 'mass fork and fire signal to child' scenario the extra 80
bytes of memory per task are well in the noise of the overall memory
consumption of the fork bomb.
If this should be limited then this would need an extra counter in struct
user, more atomic instructions and a seperate rlimit. Yet another tunable
which is mostly unused.
The caching is actually used. After boot and a full kernel compile on a
64CPU machine with make -j128 the number of 'allocations' looks like this:
From slab: 23996
From task cache: 52223
I.e. it reduces the number of slab cache operations by ~68%.
A typical pattern there is:
<...>-58490 __sigqueue_alloc: for 58488 from slab ffff8881132df460
<...>-58488 __sigqueue_free: cache ffff8881132df460
<...>-58488 __sigqueue_alloc: for 1149 from cache ffff8881103dc550
bash-1149 exit_task_sighand: free ffff8881132df460
bash-1149 __sigqueue_free: cache ffff8881103dc550
The interesting sequence is that the exiting task 58488 grabs the sigqueue
from bash's task cache to signal exit and bash sticks it back into it's own
cache. Lather, rinse and repeat.
The caching is probably not noticable for the general use case, but the
benefit for latency sensitive applications is clear. While kmem caches are
usually just serving from the fast path the slab merging (default) can
depending on the usage pattern of the merged slabs cause occasional slow
path allocations.
The time spared per cached entry is a few micro seconds per signal which is
not relevant for e.g. a kernel build, but for signal heavy workloads it's
measurable.
As there is no real downside of this caching mechanism making it
unconditionally available is preferred over more conditional code or new
magic tunables.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/87sg4lbmxo.fsf@nanos.tec.linutronix.de
Add two new kdb environment access methods as kdb_setenv() and
kdb_printenv() in order to abstract out environment access code
from kdb command functions.
Also, replace (char *)0 with NULL as an initializer for environment
variables array.
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/1612771342-16883-1-git-send-email-sumit.garg@linaro.org
[daniel.thompson@linaro.org: Replaced (char *)0/NULL initializers with
an array size]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
allnoconfig_y is an ugly hack that sets a symbol to 'y' by allnoconfig.
allnoconfig does not mean a minimal set of CONFIG options because a
bunch of prompts are hidden by 'if EMBEDDED' or 'if EXPERT', but I do
not like to hack Kconfig this way.
Use the pre-existing feature, KCONFIG_ALLCONFIG, to provide a one
liner config fragment. CONFIG_EMBEDDED=y is still forced when
allnoconfig is invoked as a part of tinyconfig.
No change in the .config file produced by 'make tinyconfig'.
The output of 'make allnoconfig' will be changed; we will get
CONFIG_EMBEDDED=n because allnoconfig literally sets all symbols to n.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull tracing fix from Steven Rostedt:
"Fix a memory link in dyn_event_release().
An error path exited the function before freeing the allocated 'argv'
variable"
* tag 'trace-v5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/dynevent: Fix a memory leak in an error handling path
This change introduces a prctl that allows the user program to control
which PAC keys are enabled in a particular task. The main reason
why this is useful is to enable a userspace ABI that uses PAC to
sign and authenticate function pointers and other pointers exposed
outside of the function, while still allowing binaries conforming
to the ABI to interoperate with legacy binaries that do not sign or
authenticate pointers.
The idea is that a dynamic loader or early startup code would issue
this prctl very early after establishing that a process may load legacy
binaries, but before executing any PAC instructions.
This change adds a small amount of overhead to kernel entry and exit
due to additional required instruction sequences.
On a DragonBoard 845c (Cortex-A75) with the powersave governor, the
overhead of similar instruction sequences was measured as 4.9ns when
simulating the common case where IA is left enabled, or 43.7ns when
simulating the uncommon case where IA is disabled. These numbers can
be seen as the worst case scenario, since in more realistic scenarios
a better performing governor would be used and a newer chip would be
used that would support PAC unlike Cortex-A75 and would be expected
to be faster than Cortex-A75.
On an Apple M1 under a hypervisor, the overhead of the entry/exit
instruction sequences introduced by this patch was measured as 0.3ns
in the case where IA is left enabled, and 33.0ns in the case where
IA is disabled.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://linux-review.googlesource.com/id/Ibc41a5e6a76b275efbaa126b31119dc197b927a5
Link: https://lore.kernel.org/r/d6609065f8f40397a4124654eb68c9f490b4d477.1616123271.git.pcc@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Change hierachy to hierarchy and unrechable to unreachable,
no functionality changed.
Signed-off-by: Lu Jialin <lujialin4@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull ARM cpufreq updates for v5.13 from Viresh Kumar:
"- Fix typos in s5pv210 cpufreq driver (Bhaskar Chowdhury).
- Armada 37xx: Fix cpufreq changing base CPU speed to 800 MHz from
1000 MHz (Pali Rohár and Marek Behún).
- cpufreq-dt: Return -EPROBE_DEFER on failure to add table (Quanyang
Wang).
- Minor cleanup in cppc driver (Tom Saeger).
- Add frequency invariance support for CPPC driver and generalize
freq invariance support arch-topology driver (Viresh Kumar)."
* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
cpufreq: armada-37xx: Fix module unloading
cpufreq: armada-37xx: Remove cur_frequency variable
cpufreq: armada-37xx: Fix determining base CPU frequency
cpufreq: armada-37xx: Fix driver cleanup when registration failed
clk: mvebu: armada-37xx-periph: Fix workaround for switching from L1 to L0
clk: mvebu: armada-37xx-periph: Fix switching CPU freq from 250 Mhz to 1 GHz
cpufreq: armada-37xx: Fix the AVS value for load L1
clk: mvebu: armada-37xx-periph: remove .set_parent method for CPU PM clock
cpufreq: armada-37xx: Fix setting TBG parent for load levels
cpufreq: dt: dev_pm_opp_of_cpumask_add_table() may return -EPROBE_DEFER
cpufreq: cppc: simplify default delay_us setting
cpufreq: Rudimentary typos fix in the file s5pv210-cpufreq.c
cpufreq: CPPC: Add support for frequency invariance
arch_topology: Export arch_freq_scale and helpers
arch_topology: Allow multiple entities to provide sched_freq_tick() callback
arch_topology: Rename freq_scale as arch_freq_scale
The only exported helper we have right now is task_work_cancel(), which
cancels any task_work from a given task where func matches the queued
work item. This is a bit too coarse for some use cases. Add a
task_work_cancel_match() that allows to more specifically target
individual work items outside of purely the callback function used.
task_work_cancel() can be trivially implemented on top of that, hence do
so.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fork() fails if signal_pending() is true, but there are two conditions
that can lead to that:
1) An actual signal is pending. We want fork to fail for that one, like
we always have.
2) TIF_NOTIFY_SIGNAL is pending, because the task has pending task_work.
We don't need to make it fail for that case.
Allow fork() to proceed if just task_work is pending, by changing the
signal_pending() check to task_sigpending().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull locking fixlets from Ingo Molnar:
"Two minor fixes: one for a Clang warning, the other improves an
ambiguous/confusing kernel log message"
* tag 'locking-urgent-2021-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep: Address clang -Wformat warning printing for %hd
lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message
Pull RCU changes from Paul E. McKenney:
- Bitmap support for "N" as alias for last bit
- kvfree_rcu updates
- mm_dump_obj() updates. (One of these is to mm, but was suggested by Andrew Morton.)
- RCU callback offloading update
- Polling RCU grace-period interfaces
- Realtime-related RCU updates
- Tasks-RCU updates
- Torture-test updates
- Torture-test scripting updates
- Miscellaneous fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
note_interrupt() increments desc->irq_count for each interrupt even for
percpu interrupt handlers, even when they are handled successfully. This
causes cacheline bouncing and limits scalability.
Instead of incrementing irq_count every time, only start incrementing it
after seeing an unhandled irq, which should avoid the cache line
bouncing in the common path.
This actually should give better consistency in handling misbehaving
irqs too, because instead of the first unhandled irq arriving at an
arbitrary point in the irq_count cycle, its arrival will begin the
irq_count cycle.
Cédric reports the result of his IPI throughput test:
Millions of IPIs/s
----------- --------------------------------------
upstream upstream patched
chips cpus default noirqdebug default (irqdebug)
----------- -----------------------------------------
1 0-15 4.061 4.153 4.084
0-31 7.937 8.186 8.158
0-47 11.018 11.392 11.233
0-63 11.460 13.907 14.022
2 0-79 8.376 18.105 18.084
0-95 7.338 22.101 22.266
0-111 6.716 25.306 25.473
0-127 6.223 27.814 28.029
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210402132037.574661-1-npiggin@gmail.com
KMSAN complains that new_value at cpumask_parse_user() from
write_irq_affinity() from irq_affinity_proc_write() is uninitialized.
[ 148.133411][ T5509] =====================================================
[ 148.135383][ T5509] BUG: KMSAN: uninit-value in find_next_bit+0x325/0x340
[ 148.137819][ T5509]
[ 148.138448][ T5509] Local variable ----new_value.i@irq_affinity_proc_write created at:
[ 148.140768][ T5509] irq_affinity_proc_write+0xc3/0x3d0
[ 148.142298][ T5509] irq_affinity_proc_write+0xc3/0x3d0
[ 148.143823][ T5509] =====================================================
Since bitmap_parse() from cpumask_parse_user() calls find_next_bit(),
any alloc_cpumask_var() + cpumask_parse_user() sequence has possibility
that find_next_bit() accesses uninitialized cpu mask variable. Fix this
problem by replacing alloc_cpumask_var() with zalloc_cpumask_var().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp
Conflicts:
MAINTAINERS
- keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
- simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
- trivial
include/linux/ethtool.h
- trivial, fix kdoc while at it
include/linux/skmsg.h
- move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
- add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
- trivial
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge misc fixes from Andrew Morton:
"14 patches.
Subsystems affected by this patch series: mm (kasan, gup, pagecache,
and kfence), MAINTAINERS, mailmap, nds32, gcov, ocfs2, ia64, and lib"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS
kfence, x86: fix preemptible warning on KPTI-enabled systems
lib/test_kasan_module.c: suppress unused var warning
kasan: fix conflict with page poisoning
fs: direct-io: fix missing sdio->boundary
ia64: fix user_stack_pointer() for ptrace()
ocfs2: fix deadlock between setattr and dio_end_io_write
gcov: re-fix clang-11+ support
nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff
mm/gup: check page posion status for coredump.
.mailmap: fix old email addresses
mailmap: update email address for Jordan Crouse
treewide: change my e-mail address, fix my name
MAINTAINERS: update CZ.NIC's Turris information