> From: Ming Lei <ming.lei@xxxxxxxxxx> > Sent: Wednesday, April 22, 2020 2:24 AM > > ... > > storvsc_suspend() -> scsi_host_block() is only called in the hibernation > > path, which is not a hot path at all, so IMHO we don't really care if it > > takes 10ms or 100ms or even 1s. :-) BTW, in my test, typically the > > Are you sure the 'we' can cover all users? I actully only meant I don't have any performance concern in this path storvsc_suspend() -> scsi_host_block() :-) Thanks for your effort to improve the scsi_host_block() API in the patch [PATCH] scsi: avoid to run synchronize_rcu for each device in scsi_host_block. > > scsi_host_block() here takes about 3ms in my 40-vCPU VM. > > If more LUNs are added, the time should be increased proportionallly, > that is why I think scsi_host_block() is bad. > > Thanks, > Ming FWIW, if the time increases linearly against the number of the LUNs, it looks typically it's still fast enough for storvsc_suspend(). Thanks, -- Dexuan
