On Tue, Oct 04, 2022 at 02:41:56AM +0000, Joel Fernandes (Google) wrote: > 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. > > Signed-off-by: Uladzislau Rezki <urezki@xxxxxxxxx> > Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> And I successfully setup Debian on KVM and verified that this fixes it, so now I have a nice reproducible rig for my 'lazy-callback-doing-a-wakeup-detector' (I wrote half the detector thanks to ideas from Steve, and will finish the other half tomorrow or so). Tested-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> thanks, - Joel > --- > 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.rc1.362.ged0d419d3c-goog >
