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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0162-srcu-replace-local_irqsave-with-a-locallock.patch | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/debian/patches-rt/0162-srcu-replace-local_irqsave-with-a-locallock.patch b/debian/patches-rt/0162-srcu-replace-local_irqsave-with-a-locallock.patch new file mode 100644 index 000000000..5cdde2079 --- /dev/null +++ b/debian/patches-rt/0162-srcu-replace-local_irqsave-with-a-locallock.patch @@ -0,0 +1,77 @@ +From 62524e62d2f224889aee36c1c134f0efb2fba025 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Thu, 12 Oct 2017 18:37:12 +0200 +Subject: [PATCH 162/347] srcu: replace local_irqsave() with a locallock +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +There are two instances which disable interrupts in order to become a +stable this_cpu_ptr() pointer. The restore part is coupled with +spin_unlock_irqrestore() which does not work on RT. +Replace the local_irq_save() call with the appropriate local_lock() +version of it. + +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + kernel/rcu/srcutree.c | 14 +++++++++----- + 1 file changed, 9 insertions(+), 5 deletions(-) + +diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c +index df0375453ba1..0f09a1a9e17c 100644 +--- a/kernel/rcu/srcutree.c ++++ b/kernel/rcu/srcutree.c +@@ -39,6 +39,7 @@ + #include <linux/module.h> + #include <linux/srcu.h> + #include <linux/cpu.h> ++#include <linux/locallock.h> + + #include "rcu.h" + #include "rcu_segcblist.h" +@@ -760,6 +761,8 @@ static void srcu_flip(struct srcu_struct *sp) + * negligible when amoritized over that time period, and the extra latency + * of a needlessly non-expedited grace period is similarly negligible. + */ ++static DEFINE_LOCAL_IRQ_LOCK(sp_llock); ++ + static bool srcu_might_be_idle(struct srcu_struct *sp) + { + unsigned long curseq; +@@ -768,13 +771,13 @@ static bool srcu_might_be_idle(struct srcu_struct *sp) + unsigned long t; + + /* If the local srcu_data structure has callbacks, not idle. */ +- local_irq_save(flags); ++ local_lock_irqsave(sp_llock, flags); + sdp = this_cpu_ptr(sp->sda); + if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) { +- local_irq_restore(flags); ++ local_unlock_irqrestore(sp_llock, flags); + return false; /* Callbacks already present, so not idle. */ + } +- local_irq_restore(flags); ++ local_unlock_irqrestore(sp_llock, flags); + + /* + * No local callbacks, so probabalistically probe global state. +@@ -852,7 +855,7 @@ void __call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, + return; + } + rhp->func = func; +- local_irq_save(flags); ++ local_lock_irqsave(sp_llock, flags); + sdp = this_cpu_ptr(sp->sda); + spin_lock_rcu_node(sdp); + rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp, false); +@@ -868,7 +871,8 @@ void __call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, + sdp->srcu_gp_seq_needed_exp = s; + needexp = true; + } +- spin_unlock_irqrestore_rcu_node(sdp, flags); ++ spin_unlock_rcu_node(sdp); ++ local_unlock_irqrestore(sp_llock, flags); + if (needgp) + srcu_funnel_gp_start(sp, sdp, s, do_norm); + else if (needexp) +-- +2.36.1 + |