On Mon, 2020-04-20 at 15:28 -0700, James Bottomley wrote: > On Mon, 2020-04-20 at 23:46 +0300, Jarkko Sakkinen wrote: <snip> > But more seriously: Nayna Jain did a series of patches improving the > time it takes to poll the TPM for operations precisely because the TPM > PCR extend was going so slowly: > > https://lore.kernel.org/linux-integrity/20180516055125.5685-1-nayna@xxxxxxxxxxxxxxxxxx/ The original reason for us needing to improve the TPM performance was due to the kernel scheduler change. Refer to commit a233a0289cf9 ("tpm: msleep() delays - replace with usleep_range() in i2c nuvoton driver"). That scheduler change prevented systems from booting. Bisecting the kernel to figure out the problem wasn't very productive. At least any TPM changes that affect the TPM performance really need to take into account IMA requirements. thanks, Mimi
