[PATCH v9 10/13] scsi/scsi_error: Use call_rcu_flush() instead of call_rcu()

From: Joel Fernandes (Google)
Date: Sun Oct 16 2022 - 12:24:47 EST


From: Uladzislau Rezki <urezki@xxxxxxxxx>

Slow boot time is seen on KVM running typical Linux distributions due to
SCSI layer calling call_rcu(). Recent changes to save power may be
causing this slowness. Using call_rcu_flush() fixes the issue and brings
the boot time back to what it originally was. Convert it.

Tested-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Signed-off-by: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_error.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 448748e3fba5..a56cfd612e3a 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -312,7 +312,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
* Ensure that all tasks observe the host state change before the
* host_failed change.
*/
- call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
+ call_rcu_flush(&scmd->rcu, scsi_eh_inc_host_failed);
}

/**
--
2.38.0.413.g74048e4d9e-goog