linux-stable.git/drivers/idle, branch linux-5.10.y Linux kernel stable tree intel_idle: Allow loading ACPI tables for any family 2025-08-28T14:22:39+00:00 Len Brown len.brown@intel.com 2025-08-08T19:37:14+00:00 d0a65363a9fd92fccb3772a9825924cda0247440 [ Upstream commit e91a158b694d7f4bd937763dde79ed0afa472d8a ] There is no reason to limit intel_idle's loading of ACPI tables to family 6. Upcoming Intel processors are not in family 6. Below "Fixes" really means "applies cleanly until". That syntax commit didn't change the previous logic, but shows this patch applies back 5-years. Fixes: 4a9f45a0533f ("intel_idle: Convert to new X86 CPU match macros") Signed-off-by: Len Brown <len.brown@intel.com> Link: https://patch.msgid.link/06101aa4fe784e5b0be1cb2c0bdd9afcf16bd9d4.1754681697.git.len.brown@intel.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e91a158b694d7f4bd937763dde79ed0afa472d8a ]

There is no reason to limit intel_idle's loading of ACPI tables to
family 6.  Upcoming Intel processors are not in family 6.

Below "Fixes" really means "applies cleanly until".
That syntax commit didn't change the previous logic,
but shows this patch applies back 5-years.

Fixes: 4a9f45a0533f ("intel_idle: Convert to new X86 CPU match macros")
Signed-off-by: Len Brown <len.brown@intel.com>
Link: https://patch.msgid.link/06101aa4fe784e5b0be1cb2c0bdd9afcf16bd9d4.1754681697.git.len.brown@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
intel_idle: Handle older CPUs, which stop the TSC in deeper C states, correctly 2025-03-13T11:47:34+00:00 Thomas Gleixner tglx@linutronix.de 2025-02-25T22:37:08+00:00 8045b302301e64080e3be6a656d626d0aa30877d commit c157d351460bcf202970e97e611cb6b54a3dd4a4 upstream. The Intel idle driver is preferred over the ACPI processor idle driver, but fails to implement the work around for Core2 generation CPUs, where the TSC stops in C2 and deeper C-states. This causes stalls and boot delays, when the clocksource watchdog does not catch the unstable TSC before the CPU goes deep idle for the first time. The ACPI driver marks the TSC unstable when it detects that the CPU supports C2 or deeper and the CPU does not have a non-stop TSC. Add the equivivalent work around to the Intel idle driver to cure that. Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables") Reported-by: Fab Stz <fabstz-it@yahoo.fr> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Fab Stz <fabstz-it@yahoo.fr> Cc: All applicable <stable@vger.kernel.org> Closes: https://lore.kernel.org/all/10cf96aa-1276-4bd4-8966-c890377030c3@yahoo.fr Link: https://patch.msgid.link/87bjupfy7f.ffs@tglx Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c157d351460bcf202970e97e611cb6b54a3dd4a4 upstream.

The Intel idle driver is preferred over the ACPI processor idle driver,
but fails to implement the work around for Core2 generation CPUs, where
the TSC stops in C2 and deeper C-states. This causes stalls and boot
delays, when the clocksource watchdog does not catch the unstable TSC
before the CPU goes deep idle for the first time.

The ACPI driver marks the TSC unstable when it detects that the CPU
supports C2 or deeper and the CPU does not have a non-stop TSC.

Add the equivivalent work around to the Intel idle driver to cure that.

Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: Fab Stz <fabstz-it@yahoo.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Fab Stz <fabstz-it@yahoo.fr>
Cc: All applicable <stable@vger.kernel.org>
Closes: https://lore.kernel.org/all/10cf96aa-1276-4bd4-8966-c890377030c3@yahoo.fr
Link: https://patch.msgid.link/87bjupfy7f.ffs@tglx
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel_idle: Disable IBRS during long idle 2022-07-25T09:26:43+00:00 Peter Zijlstra peterz@infradead.org 2022-06-14T21:15:58+00:00 55bba093fd91a76971134e3a4e3576e536c08f5c commit bf5835bcdb9635c97f85120dba9bfa21e111130f upstream. Having IBRS enabled while the SMT sibling is idle unnecessarily slows down the running sibling. OTOH, disabling IBRS around idle takes two MSR writes, which will increase the idle latency. Therefore, only disable IBRS around deeper idle states. Shallow idle states are bounded by the tick in duration, since NOHZ is not allowed for them by virtue of their short target residency. Only do this for mwait-driven idle, since that keeps interrupts disabled across idle, which makes disabling IBRS vs IRQ-entry a non-issue. Note: C6 is a random threshold, most importantly C1 probably shouldn't disable IBRS, benchmarking needed. Suggested-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> [cascardo: no CPUIDLE_FLAG_IRQ_ENABLE] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bf5835bcdb9635c97f85120dba9bfa21e111130f upstream.

Having IBRS enabled while the SMT sibling is idle unnecessarily slows
down the running sibling. OTOH, disabling IBRS around idle takes two
MSR writes, which will increase the idle latency.

Therefore, only disable IBRS around deeper idle states. Shallow idle
states are bounded by the tick in duration, since NOHZ is not allowed
for them by virtue of their short target residency.

Only do this for mwait-driven idle, since that keeps interrupts disabled
across idle, which makes disabling IBRS vs IRQ-entry a non-issue.

Note: C6 is a random threshold, most importantly C1 probably shouldn't
disable IBRS, benchmarking needed.

Suggested-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: no CPUIDLE_FLAG_IRQ_ENABLE]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel_idle: Build fix 2020-12-03T09:00:23+00:00 Peter Zijlstra peterz@infradead.org 2020-11-30T11:54:34+00:00 4d916140bf28ff027997144ea1bb4299e1536f87 Because CONFIG_ soup. Fixes: 6e1d2bc675bd ("intel_idle: Fix intel_idle() vs tracing") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201130115402.GO3040@hirez.programming.kicks-ass.net 
Because CONFIG_ soup.

Fixes: 6e1d2bc675bd ("intel_idle: Fix intel_idle() vs tracing")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201130115402.GO3040@hirez.programming.kicks-ass.net
intel_idle: Fix intel_idle() vs tracing 2020-11-24T15:47:36+00:00 Peter Zijlstra peterz@infradead.org 2020-11-20T10:28:35+00:00 6e1d2bc675bd57640f5658a4a657ae488db4c204 cpuidle->enter() callbacks should not call into tracing because RCU has already been disabled. Instead of doing the broadcast thing itself, simply advertise to the cpuidle core that those states stop the timer. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lkml.kernel.org/r/20201123143510.GR3021@hirez.programming.kicks-ass.net 
cpuidle->enter() callbacks should not call into tracing because RCU
has already been disabled. Instead of doing the broadcast thing
itself, simply advertise to the cpuidle core that those states stop
the timer.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20201123143510.GR3021@hirez.programming.kicks-ass.net
intel_idle: Fix max_cstate for processor models without C-state tables 2020-10-27T18:03:53+00:00 Chen Yu yu.c.chen@intel.com 2020-10-24T16:29:53+00:00 4e0ba5577dba686f96c1c10ef4166380667fdec7 Currently intel_idle driver gets the c-state information from ACPI _CST if the processor model is not recognized by it. However the c-state in _CST starts with index 1 which is different from the index in intel_idle driver's internal c-state table. While intel_idle_max_cstate_reached() was previously introduced to deal with intel_idle driver's internal c-state table, re-using this function directly on _CST is incorrect. Fix this by subtracting 1 from the index when checking max_cstate in the _CST case. For example, append intel_idle.max_cstate=1 in boot command line, Before the patch: grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name POLL After the patch: grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name /sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL /sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1_ACPI Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Cc: 5.6+ <stable@vger.kernel.org> # 5.6+ Signed-off-by: Chen Yu <yu.c.chen@intel.com> [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Currently intel_idle driver gets the c-state information from ACPI
_CST if the processor model is not recognized by it. However the
c-state in _CST starts with index 1 which is different from the
index in intel_idle driver's internal c-state table.

While intel_idle_max_cstate_reached() was previously introduced to
deal with intel_idle driver's internal c-state table, re-using
this function directly on _CST is incorrect.

Fix this by subtracting 1 from the index when checking max_cstate
in the _CST case.

For example, append intel_idle.max_cstate=1 in boot command line,
Before the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
POLL
After the patch:
grep . /sys/devices/system/cpu/cpu0/cpuidle/state*/name
/sys/devices/system/cpu/cpu0/cpuidle/state0/name:POLL
/sys/devices/system/cpu/cpu0/cpuidle/state1/name:C1_ACPI

Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Cc: 5.6+ <stable@vger.kernel.org> # 5.6+
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_idle: Ignore _CST if control cannot be taken from the platform 2020-10-16T15:28:32+00:00 Mel Gorman mgorman@techsingularity.net 2020-10-16T15:28:32+00:00 75af76d0a34e048651a6af311781d7206b6964c7 e6d4f08a6776 ("intel_idle: Use ACPI _CST on server systems") avoids enabling c-states that have been disabled by the platform with the exception of C1E. Unfortunately, BIOS implementations are not always consistent in terms of how capabilities are advertised and control cannot always be handed over. If control cannot be handed over then intel_idle reports that "ACPI _CST not found or not usable" but does not clear acpi_state_table.count meaning the information is still partially used. This patch ignores ACPI information if CST control cannot be requested from the platform. This was only observed on a number of Haswell platforms that had identical CPUs but not identical BIOS versions. While this problem may be rare overall, 24 separate test cases bisected to this specific commit across 4 separate test machines and is worth addressing. If the situation occurs, the kernel behaves as it did before commit e6d4f08a6776 and uses any c-states that are discovered. The affected test cases were all ones that involved a small number of processes -- exec microbenchmark, pipe microbenchmark, git test suite, netperf, tbench with one client and system call microbenchmark. Each case benefits from being able to use turboboost which is prevented if the lower c-states are unavailable. This may mask real regressions specific to older hardware so it is worth addressing. C-state status before and after the patch 5.9.0-vanilla POLL latency:0 disabled:0 default:enabled 5.9.0-vanilla C1 latency:2 disabled:0 default:enabled 5.9.0-vanilla C1E latency:10 disabled:0 default:enabled 5.9.0-vanilla C3 latency:33 disabled:1 default:disabled 5.9.0-vanilla C6 latency:133 disabled:1 default:disabled 5.9.0-ignore-cst-v1r1 POLL latency:0 disabled:0 default:enabled 5.9.0-ignore-cst-v1r1 C1 latency:2 disabled:0 default:enabled 5.9.0-ignore-cst-v1r1 C1E latency:10 disabled:0 default:enabled 5.9.0-ignore-cst-v1r1 C3 latency:33 disabled:0 default:enabled 5.9.0-ignore-cst-v1r1 C6 latency:133 disabled:0 default:enabled Patch enables C3/C6. Netperf UDP_STREAM netperf-udp 5.5.0 5.9.0 vanilla ignore-cst-v1r1 Hmean send-64 193.41 ( 0.00%) 226.54 * 17.13%* Hmean send-128 392.16 ( 0.00%) 450.54 * 14.89%* Hmean send-256 769.94 ( 0.00%) 881.85 * 14.53%* Hmean send-1024 2994.21 ( 0.00%) 3468.95 * 15.85%* Hmean send-2048 5725.60 ( 0.00%) 6628.99 * 15.78%* Hmean send-3312 8468.36 ( 0.00%) 10288.02 * 21.49%* Hmean send-4096 10135.46 ( 0.00%) 12387.57 * 22.22%* Hmean send-8192 17142.07 ( 0.00%) 19748.11 * 15.20%* Hmean send-16384 28539.71 ( 0.00%) 30084.45 * 5.41%* Fixes: e6d4f08a6776 ("intel_idle: Use ACPI _CST on server systems") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: 5.6+ <stable@vger.kernel.org> # 5.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
e6d4f08a6776 ("intel_idle: Use ACPI _CST on server systems") avoids
enabling c-states that have been disabled by the platform with the
exception of C1E.

Unfortunately, BIOS implementations are not always consistent in terms
of how capabilities are advertised and control cannot always be handed
over. If control cannot be handed over then intel_idle reports that "ACPI
_CST not found or not usable" but does not clear acpi_state_table.count
meaning the information is still partially used.

This patch ignores ACPI information if CST control cannot be requested from
the platform. This was only observed on a number of Haswell platforms that
had identical CPUs but not identical BIOS versions.  While this problem
may be rare overall, 24 separate test cases bisected to this specific
commit across 4 separate test machines and is worth addressing. If the
situation occurs, the kernel behaves as it did before commit e6d4f08a6776
and uses any c-states that are discovered.

The affected test cases were all ones that involved a small number of
processes -- exec microbenchmark, pipe microbenchmark, git test suite,
netperf, tbench with one client and system call microbenchmark. Each
case benefits from being able to use turboboost which is prevented if the
lower c-states are unavailable. This may mask real regressions specific
to older hardware so it is worth addressing.

C-state status before and after the patch

5.9.0-vanilla            POLL     latency:0      disabled:0 default:enabled
5.9.0-vanilla            C1       latency:2      disabled:0 default:enabled
5.9.0-vanilla            C1E      latency:10     disabled:0 default:enabled
5.9.0-vanilla            C3       latency:33     disabled:1 default:disabled
5.9.0-vanilla            C6       latency:133    disabled:1 default:disabled
5.9.0-ignore-cst-v1r1    POLL     latency:0      disabled:0 default:enabled
5.9.0-ignore-cst-v1r1    C1       latency:2      disabled:0 default:enabled
5.9.0-ignore-cst-v1r1    C1E      latency:10     disabled:0 default:enabled
5.9.0-ignore-cst-v1r1    C3       latency:33     disabled:0 default:enabled
5.9.0-ignore-cst-v1r1    C6       latency:133    disabled:0 default:enabled

Patch enables C3/C6.

Netperf UDP_STREAM

netperf-udp
                                      5.5.0                  5.9.0
                                    vanilla        ignore-cst-v1r1
Hmean     send-64         193.41 (   0.00%)      226.54 *  17.13%*
Hmean     send-128        392.16 (   0.00%)      450.54 *  14.89%*
Hmean     send-256        769.94 (   0.00%)      881.85 *  14.53%*
Hmean     send-1024      2994.21 (   0.00%)     3468.95 *  15.85%*
Hmean     send-2048      5725.60 (   0.00%)     6628.99 *  15.78%*
Hmean     send-3312      8468.36 (   0.00%)    10288.02 *  21.49%*
Hmean     send-4096     10135.46 (   0.00%)    12387.57 *  22.22%*
Hmean     send-8192     17142.07 (   0.00%)    19748.11 *  15.20%*
Hmean     send-16384    28539.71 (   0.00%)    30084.45 *   5.41%*

Fixes: e6d4f08a6776 ("intel_idle: Use ACPI _CST on server systems")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: 5.6+ <stable@vger.kernel.org> # 5.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_idle: mention assumption that WBINVD is not needed 2020-10-16T15:09:14+00:00 Alexander Monakov amonakov@ispras.ru 2020-10-12T12:50:33+00:00 8bb2e2a887afdf8a39e68fa0dccf82a168aae655 Intel SDM does not explicitly say that entering a C-state via MWAIT will implicitly flush CPU caches as appropriate for that C-state. However, documentation for individual Intel CPU generations does mention this behavior. Since intel_idle binds to any Intel CPU with MWAIT, list this assumption of MWAIT behavior. In passing, reword opening comment to make it clear that the driver can load on any old and future Intel CPU with MWAIT. Signed-off-by: Alexander Monakov <amonakov@ispras.ru> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Intel SDM does not explicitly say that entering a C-state via MWAIT will
implicitly flush CPU caches as appropriate for that C-state. However,
documentation for individual Intel CPU generations does mention this
behavior.

Since intel_idle binds to any Intel CPU with MWAIT, list this assumption
of MWAIT behavior.

In passing, reword opening comment to make it clear that the driver can
load on any old and future Intel CPU with MWAIT.

Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic 2020-08-26T10:41:53+00:00 Peter Zijlstra peterz@infradead.org 2020-08-12T10:22:17+00:00 bf9282dc26e7fe2a0736edc568762f0f05d12416 This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org 
This allows moving the leave_mm() call into generic code before
rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
Merge tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 2020-08-04T20:49:43+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-08-04T20:49:43+00:00 99ea1521a097db51f0f04f54cfbd3b0ed119d2f1 Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var() 
Pull uninitialized_var() macro removal from Kees Cook:
 "This is long overdue, and has hidden too many bugs over the years. The
  series has several "by hand" fixes, and then a trivial treewide
  replacement.

   - Clean up non-trivial uses of uninitialized_var()

   - Update documentation and checkpatch for uninitialized_var() removal

   - Treewide removal of uninitialized_var()"

* tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  compiler: Remove uninitialized_var() macro
  treewide: Remove uninitialized_var() usage
  checkpatch: Remove awareness of uninitialized_var() macro
  mm/debug_vm_pgtable: Remove uninitialized_var() usage
  f2fs: Eliminate usage of uninitialized_var() macro
  media: sur40: Remove uninitialized_var() usage
  KVM: PPC: Book3S PR: Remove uninitialized_var() usage
  clk: spear: Remove uninitialized_var() usage
  clk: st: Remove uninitialized_var() usage
  spi: davinci: Remove uninitialized_var() usage
  ide: Remove uninitialized_var() usage
  rtlwifi: rtl8192cu: Remove uninitialized_var() usage
  b43: Remove uninitialized_var() usage
  drbd: Remove uninitialized_var() usage
  x86/mm/numa: Remove uninitialized_var() usage
  docs: deprecated.rst: Add uninitialized_var()