From: Jakub Kicinski <kuba@kernel.org>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com,
Jakub Kicinski <kuba@kernel.org>,
peterz@infradead.org, mingo@redhat.com, will@kernel.org,
longman@redhat.com, boqun.feng@gmail.com, hawk@kernel.org,
ilias.apalodimas@linaro.org
Subject: [PATCH net-next] page_pool: add a lockdep check for recycling in hardirq
Date: Thu, 20 Jul 2023 10:37:51 -0700 [thread overview]
Message-ID: <20230720173752.2038136-1-kuba@kernel.org> (raw)
Page pool use in hardirq is prohibited, add debug checks
to catch misuses. IIRC we previously discussed using
DEBUG_NET_WARN_ON_ONCE() for this, but there were concerns
that people will have DEBUG_NET enabled in perf testing.
I don't think anyone enables lockdep in perf testing,
so use lockdep to avoid pushback and arguing :)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: peterz@infradead.org
CC: mingo@redhat.com
CC: will@kernel.org
CC: longman@redhat.com
CC: boqun.feng@gmail.com
CC: hawk@kernel.org
CC: ilias.apalodimas@linaro.org
---
include/linux/lockdep.h | 7 +++++++
net/core/page_pool.c | 4 ++++
2 files changed, 11 insertions(+)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 310f85903c91..dc2844b071c2 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -625,6 +625,12 @@ do { \
WARN_ON_ONCE(__lockdep_enabled && !this_cpu_read(hardirq_context)); \
} while (0)
+#define lockdep_assert_no_hardirq() \
+do { \
+ WARN_ON_ONCE(__lockdep_enabled && (this_cpu_read(hardirq_context) || \
+ !this_cpu_read(hardirqs_enabled))); \
+} while (0)
+
#define lockdep_assert_preemption_enabled() \
do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
@@ -659,6 +665,7 @@ do { \
# define lockdep_assert_irqs_enabled() do { } while (0)
# define lockdep_assert_irqs_disabled() do { } while (0)
# define lockdep_assert_in_irq() do { } while (0)
+# define lockdep_assert_no_hardirq() do { } while (0)
# define lockdep_assert_preemption_enabled() do { } while (0)
# define lockdep_assert_preemption_disabled() do { } while (0)
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index a3e12a61d456..3ac760fcdc22 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -536,6 +536,8 @@ static void page_pool_return_page(struct page_pool *pool, struct page *page)
static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
{
int ret;
+
+ lockdep_assert_no_hardirq();
/* BH protection not needed if current is softirq */
if (in_softirq())
ret = ptr_ring_produce(&pool->ring, page);
@@ -642,6 +644,8 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
int i, bulk_len = 0;
bool in_softirq;
+ lockdep_assert_no_hardirq();
+
for (i = 0; i < count; i++) {
struct page *page = virt_to_head_page(data[i]);
--
2.41.0
next reply other threads:[~2023-07-20 17:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 17:37 Jakub Kicinski [this message]
2023-07-21 11:53 ` [PATCH net-next] page_pool: add a lockdep check for recycling in hardirq Yunsheng Lin
2023-07-21 15:02 ` Jakub Kicinski
2023-07-21 15:48 ` Alexander Lobakin
2023-07-21 16:05 ` Jakub Kicinski
2023-07-21 16:33 ` Alexander Lobakin
2023-07-22 1:45 ` Jakub Kicinski
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