On 06.10.2023 23:54, Vladimir 'phcoder' Serbinenko wrote:
Le ven. 6 oct. 2023, 19:13, ValdikSS via Grub-devel <grub-devel@gnu.org <mailto:grub-devel@gnu.org>> a écrit :Increase the value from 63 to speed up reading process. This commit increases two limits: the low-level int 13h reading code and a high-level reading code with disk cache. These are 2 independent changes and need to be discussed separately.E.g. it has an unintentional effect of doubling the cache size. I wonder if this alone might explain your speed-up.
It is not. That was probably the first thing I have tried, as I found somewhat similar issues with UEFI loading from 2012 which were solved by increased cache:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/944347
The performance problem appears to be due to overhead of the individual disk read calls... grub2's disk I/O layer buffers 8 disk sectors per read, hard-coded in include/grub/disk.h as GRUB_DISK_CACHE_SIZE. Increasing GRUB_DISK_CACHE_SIZE to 1024 (patch attached) dramatically improves the load performance for my Intel Tunnel Mountain system booting with UEFI: total load time for linux and initrd is reduced from about 53 seconds to about 1 second.
But that is not the reason for my issue.P.S. Vladimir, please send emails to me with my email address in To/CC, I'm not subscribed to every message in the mail list.
OpenPGP_signature
Description: OpenPGP digital signature
_______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
