On Mon, 02 May 2016 23:17:41 +0300 Oleksandr Natalenko <oleksa...@natalenko.name> wrote:
> This patch has already been posted to LKML by Ben Hutchings ~6 months > ago, but AFAIK no further action were performed. However, this patch > really fixes weird loadavg with RTS5129 card reader, so I would wonder > if this could be merged. AFAIK, it has been applied to some distros' > kernels, e.g., Ubuntu. > > Original Ben's message goes below. > > rtsx_usb_ms creates a task that mostly sleeps, but tasks in > uninterruptible sleep still contribute to the load average (for > bug-compatibility with Unix). A load average of ~1 on a system that > should be idle is somewhat alarming. > > Change the sleep to be interruptible, but still ignore signals. > > A better fix might be to replace this loop with a delayed work item. > hm. > index 1105db2..645dede 100644 > --- a/drivers/memstick/host/rtsx_usb_ms.c > +++ b/drivers/memstick/host/rtsx_usb_ms.c > @@ -706,7 +706,8 @@ poll_again: > if (host->eject) > break; > > - msleep(1000); > + if (msleep_interruptible(1000)) > + flush_signals(current); > } > > complete(&host->detect_ms_exit); flush_signals() is a bit scary. If this was a userspace task and it had (say) SIGINT pending then it would be very rude for a device driver to rub that out. But this isn't a userspace task - it's a kthread. So I don't *think* it can get any signals anyway? And looking at Oleg's 9e7c8f8c62c1e1cda203b it appears that flush_signals() is for flushing signals of a userspace task, not a kthread? Despite the comment "Flush all pending signals for this kthread". Confused. It's been a while since I looked at this stuff and people have mucked with it. Oleg, can you please sort me out?
