From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>, Marco Elver <elver@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Tomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
akpm@linux-foundation.org, cl@linux.com, iamjoonsoo.kim@lge.com,
longman@redhat.com, penberg@kernel.org, rientjes@google.com,
sfr@canb.auug.org.au,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH v2 2/3] scftorture: Move memory allocation outside of preempt_disable region.
Date: Thu, 7 Nov 2024 12:13:07 +0100 [thread overview]
Message-ID: <20241107111821.3417762-3-bigeasy@linutronix.de> (raw)
In-Reply-To: <20241107111821.3417762-1-bigeasy@linutronix.de>
Memory allocations can not happen within regions with explicit disabled
preemption PREEMPT_RT. The problem is that the locking structures
underneath are sleeping locks.
Move the memory allocation outside of the preempt-disabled section. Keep
the GFP_ATOMIC for the allocation to behave like a "ememergncy
allocation".
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/scftorture.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 455cbff35a1a2..555b3b10621fe 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -320,10 +320,6 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
struct scf_check *scfcp = NULL;
struct scf_selector *scfsp = scf_sel_rand(trsp);
- if (use_cpus_read_lock)
- cpus_read_lock();
- else
- preempt_disable();
if (scfsp->scfs_prim == SCF_PRIM_SINGLE || scfsp->scfs_wait) {
scfcp = kmalloc(sizeof(*scfcp), GFP_ATOMIC);
if (!scfcp) {
@@ -337,6 +333,10 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
scfcp->scfc_rpc = false;
}
}
+ if (use_cpus_read_lock)
+ cpus_read_lock();
+ else
+ preempt_disable();
switch (scfsp->scfs_prim) {
case SCF_PRIM_RESCHED:
if (IS_BUILTIN(CONFIG_SCF_TORTURE_TEST)) {
--
2.45.2
next prev parent reply other threads:[~2024-11-07 11:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-07 11:13 [PATCH v2 0/3] scftorture: Avoid kfree from IRQ context Sebastian Andrzej Siewior
2024-11-07 11:13 ` [PATCH v2 1/3] scftorture: Avoid additional div operation Sebastian Andrzej Siewior
2024-11-07 11:13 ` Sebastian Andrzej Siewior [this message]
2024-11-07 11:13 ` [PATCH v2 3/3] scftorture: Use a lock-less list to free memory Sebastian Andrzej Siewior
2024-11-07 18:31 ` Paul E. McKenney
2024-11-07 20:45 ` Boqun Feng
2024-11-07 21:53 ` Paul E. McKenney
2024-11-08 10:32 ` Sebastian Andrzej Siewior
2024-11-07 15:27 ` [PATCH v2 4/3] scftorture: Wait until scf_cleanup_handler() completes Sebastian Andrzej Siewior
2024-11-07 19:05 ` [PATCH v2 0/3] scftorture: Avoid kfree from IRQ context Paul E. McKenney
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