Hi, A gentle ping. With many patches posted these days, I hope this one is not overlooked.
A quick note: This fixes a one second latency for each text input in the grub interactive shell/editor when the image is net booted, as reported on mkvterm on powerhmc, caused quite a few complaints from our internal lab and QA. Thanks, Michael On Mon, May 06, 2024 at 10:34:22AM GMT, Michael Chang wrote: > When grub image is netbooted on ppc64le, the keyboard input exhibits > significant latency, reports even say that characters are processed > about once per second. This issue makes interactively trying to debug a > ppc64le config very difficult. > > It seems that the latency is largely caused by a 200 ms timeout in the > idle event loop, during which the network card interface is consistently > polled for incoming packets. Often, no packets arrive during this > period, so the timeout nearly always expires, which blocks the response > to key inputs. > > Furthermore, this 200 ms timeout might not need to be enforced at this > basic layer, considering that grub performs synchronous reads and its > timeout management is actually handled by higher layers, not directly in > the card instance. Additionally, the idle polling, which reacts to > unsolicited packets like ICMP and SLAAC, would be fine at a less > frequent polling interval, rather than needing a timeout for receiving a > response. > > For these reasons, we believe the timeout in get_card_packet should be > effectively removed. According to test results, the delay has > disappeared, and it is now much easier to use interactively. > > Signed-Off-by: Michael Chang <mch...@suse.com> > Tested-by: Tony Jones <to...@suse.com> > --- > grub-core/net/drivers/ieee1275/ofnet.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/grub-core/net/drivers/ieee1275/ofnet.c > b/grub-core/net/drivers/ieee1275/ofnet.c > index 78f03df8e..3bf48b3f0 100644 > --- a/grub-core/net/drivers/ieee1275/ofnet.c > +++ b/grub-core/net/drivers/ieee1275/ofnet.c > @@ -82,15 +82,11 @@ get_card_packet (struct grub_net_card *dev) > grub_ssize_t actual; > int rc; > struct grub_ofnetcard_data *data = dev->data; > - grub_uint64_t start_time; > struct grub_net_buff *nb; > > - start_time = grub_get_time_ms (); > - do > - rc = grub_ieee1275_read (data->handle, dev->rcvbuf, dev->rcvbufsize, > &actual); > - while ((actual <= 0 || rc < 0) && (grub_get_time_ms () - start_time < > 200)); > + rc = grub_ieee1275_read (data->handle, dev->rcvbuf, dev->rcvbufsize, > &actual); > > - if (actual <= 0) > + if (actual <= 0 || rc < 0) > return NULL; > > nb = grub_netbuff_alloc (actual + 2); > -- > 2.44.0 > _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
