From 90c6aad822ad054d318d291ff811dbf02633070a Mon Sep 17 00:00:00 2001 Message-Id: <90c6aad822ad054d318d291ff811dbf02633070a.1601675152.git.zanussi@kernel.org> In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org> From: Thomas Gleixner Date: Wed, 7 Mar 2012 21:10:04 +0100 Subject: [PATCH 188/333] net: Use cpu_chill() instead of cpu_relax() Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz Retry loops on RT might loop forever when the modifying side was preempted. Use cpu_chill() instead of cpu_relax() to let the system make progress. Signed-off-by: Thomas Gleixner --- net/packet/af_packet.c | 5 +++-- net/rds/ib_rdma.c | 3 ++- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index b3caf1eac6af..7d58aa1a3fa2 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -63,6 +63,7 @@ #include #include #include +#include #include #include #include @@ -668,7 +669,7 @@ static void prb_retire_rx_blk_timer_expired(struct timer_list *t) if (BLOCK_NUM_PKTS(pbd)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ - cpu_relax(); + cpu_chill(); } } @@ -930,7 +931,7 @@ static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, if (!(status & TP_STATUS_BLK_TMO)) { while (atomic_read(&pkc->blk_fill_in_prog)) { /* Waiting for skb_copy_bits to finish... */ - cpu_relax(); + cpu_chill(); } } prb_close_block(pkc, pbd, po, status); diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c index 0b347f46b2f4..f395f06031bc 100644 --- a/net/rds/ib_rdma.c +++ b/net/rds/ib_rdma.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "rds_single_path.h" #include "ib_mr.h" @@ -222,7 +223,7 @@ static inline void wait_clean_list_grace(void) for_each_online_cpu(cpu) { flag = &per_cpu(clean_list_grace, cpu); while (test_bit(CLEAN_LIST_BUSY_BIT, flag)) - cpu_relax(); + cpu_chill(); } } -- 2.17.1