On Thu, Sep 27, 2018 at 08:34:59PM +0200, Goffredo Baroncelli wrote: > From: Goffredo Baroncelli <kreijack@xxxxxxxxx> > > Change the behavior of find_device(): before the patch, a read of a missed > device may trigger a rescan. However, it is never recorded that a device > is missed, so each single read of a missed device may triggers a rescan. > It is the caller who decides if a rescan is performed in case of a missed > device. And it does quite often, without considering if in the past a > devices was already found as "missed" > This behavior causes a lot of unneeded rescan, causing a huge slowdown in > case of a missed device. > > After the patch, the "missed device" information is stored in the > data->devices_attached[] array (as a NULL value in the field dev). A rescan > is triggered only if no information at all is found. This means that only > the first time a read of a missed device triggers a rescan. > > The change in the code is done removing "return NULL" when the disk is not > found. So it is always executed the code which stores in the > data->devices_attached[] array the value returned by grub_device_iterate(): > NULL if the device is missed, or a valid data otherwise. > > Signed-off-by: Goffredo Baroncelli <kreikack@xxxxxxxxx> Commit message still begs for improvement. I will send you a proposal shortly. Daniel
