From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Julia Cartwright <julia@ni.com>,
Daniel Wagner <daniel.wagner@siemens.com>,
tom.zanussi@linux.intel.com
Subject: [PATCH RT 15/22] efi: Disable runtime services on RT
Date: Wed, 05 Sep 2018 08:28:09 -0400 [thread overview]
Message-ID: <20180905122836.778456153@goodmis.org> (raw)
In-Reply-To: 20180905122754.443196118@goodmis.org
4.14.63-rt41-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 55544e1d5eb0d7608e2b41452729649c8ea1607a ]
Based on meassurements the EFI functions get_variable /
get_next_variable take up to 2us which looks okay.
The functions get_time, set_time take around 10ms. Those 10ms are too
much. Even one ms would be too much.
Ard mentioned that SetVariable might even trigger larger latencies if
the firware will erase flash blocks on NOR.
The time-functions are used by efi-rtc and can be triggered during
runtimed (either via explicit read/write or ntp sync).
The variable write could be used by pstore.
These functions can be disabled without much of a loss. The poweroff /
reboot hooks may be provided by PSCI.
Disable EFI's runtime wrappers.
This was observed on "EFI v2.60 by SoftIron Overdrive 1000".
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
drivers/firmware/efi/efi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 9bd749389f31..47093745a53c 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -74,7 +74,7 @@ static unsigned long *efi_tables[] = {
&efi.mem_attr_table,
};
-static bool disable_runtime;
+static bool disable_runtime = IS_ENABLED(CONFIG_PREEMPT_RT_BASE);
static int __init setup_noefi(char *arg)
{
disable_runtime = true;
--
2.18.0
next prev parent reply other threads:[~2018-09-05 12:29 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 12:27 [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 01/22] sched/fair: Fix CFS bandwidth control lockdep DEADLOCK report Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 02/22] locallock: provide {get,put}_locked_ptr() variants Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 03/22] squashfs: make use of local lock in multi_cpu decompressor Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 04/22] PM / suspend: Prevent might sleep splats (updated) Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 05/22] PM / wakeup: Make events_lock a RAW_SPINLOCK Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 06/22] PM / s2idle: Make s2idle_wait_head swait based Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 07/22] seqlock: provide the same ordering semantics as mainline Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 08/22] Revert "x86: UV: raw_spinlock conversion" Steven Rostedt
2018-09-06 7:35 ` Sebastian Andrzej Siewior
2018-09-06 8:38 ` Mike Galbraith
2018-09-06 12:58 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 09/22] Revert "timer: delay waking softirqs from the jiffy tick" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 10/22] irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 11/22] irqchip/gic-v3-its: Move ITS ->pend_page allocation into an early CPU up hook Steven Rostedt
2018-09-06 7:40 ` Sebastian Andrzej Siewior
2018-09-07 19:28 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 12/22] sched/migrate_disable: fallback to preempt_disable() instead barrier() Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 13/22] x86/ioapic: Dont let setaffinity unmask threaded EOI interrupt too early Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 14/22] efi: Allow efi=runtime Steven Rostedt
2018-09-05 12:28 ` Steven Rostedt [this message]
2018-09-05 12:28 ` [PATCH RT 16/22] crypto: cryptd - add a lock instead preempt_disable/local_bh_disable Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 17/22] crypto: scompress - serialize RT percpu scratch buffer access with a local lock Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 18/22] sched/core: Avoid __schedule() being called twice in a row Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 19/22] Revert "arm64/xen: Make XEN depend on !RT" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 20/22] sched: Allow pinned user tasks to be awakened to the CPU they pinned Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 22/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
[not found] ` <20180905122837.830614967@goodmis.org>
2018-09-05 12:34 ` [PATCH RT 21/22] Drivers: hv: vmbus: include header for get_irq_regs() Steven Rostedt
2018-09-06 7:54 ` [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Sebastian Andrzej Siewior
2018-09-06 16:43 ` Steven Rostedt
2018-09-06 19:30 ` Sebastian Andrzej Siewior
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