Dear Linux folks,
Trying to optimize the boot time of Linux on the Dell XPS 13 9360,
probing of MSFT0101:00 takes 52 ms, making `init_tis()` taking almost 10
% alone until starting the initrd:
[ 0.000000] Linux version 6.8.0-rc4
(build@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) (gcc (Debian 13.2.0-13) 13.2.0,
GNU ld (GNU Binutils for Debian) 2.42) #20 SMP PREEMPT_DYNAMIC Mon Feb
12 09:40:49 CET 2024
[…]
[ 0.000000] DMI: Dell Inc. XPS 13 9360/0596KF, BIOS 2.21.0
06/02/2022
[…]
[ 0.320057] calling init_tis+0x0/0x100 @ 1
[ 0.332190] tpm_tis MSFT0101:00: 2.0 TPM (device-id 0xFE, rev-id 4)
[ 0.372164] probe of MSFT0101:00 returned 0 after 52101 usecs
[ 0.372186] initcall init_tis+0x0/0x100 returned 0 after 52127 usecs
[…]
[ 0.588643] Freeing unused decrypted memory: 2036K
[ 0.589068] Freeing unused kernel image (initmem) memory: 3976K
[ 0.606115] Write protecting the kernel read-only data: 22528k
[ 0.606527] Freeing unused kernel image (rodata/data gap)
memory: 276K
[ 0.652327] x86/mm: Checked W+X mappings: passed, no W+X pages
found.
[ 0.652329] x86/mm: Checking user space page tables
[ 0.695968] x86/mm: Checked W+X mappings: passed, no W+X pages
found.
[ 0.696104] Run /init as init process
[…]
For users, where boot time is most important, can this be moved out of
the hot path somehow?
Kind regards,
Paul
