d35ff22516
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 <mchang@suse.com> Tested-by: Tony Jones <tonyj@suse.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This is GRUB 2, the second version of the GRand Unified Bootloader. GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more robust, more powerful, and more portable. See the file NEWS for a description of recent changes to GRUB 2. See the file INSTALL for instructions on how to build and install the GRUB 2 data and program files. See the file MAINTAINERS for information about the GRUB maintainers, etc. If you found a security vulnerability in the GRUB please check the SECURITY file to get more information how to properly report this kind of bugs to the maintainers. Please visit the official web page of GRUB 2, for more information. The URL is <http://www.gnu.org/software/grub/grub.html>. More extensive documentation is available in the Info manual, accessible using 'info grub' after building and installing GRUB 2. There are a number of important user-visible differences from the first version of GRUB, now known as GRUB Legacy. For a summary, please see: info grub Introduction 'Changes from GRUB Legacy'