• Anton Ivanov's avatar
    um: Revert to using stack for pt_regs in signal handling · 5c2ffce1
    Anton Ivanov authored
    Reverts commit b6024b21 and
    adjusts default stack sizing to cope with larger size of
    floating point save registers on the newer Intel CPUs.
    
    b6024b21 replaced storing the
    register state on the stack with kmalloc-ed storage. That has
    a number of issues and a panic if that fails.
        1. kmalloc/ATOMIC can fail. There was a latent hard crash
    in all interrupt and fault handling as a result.
        2. kmalloc in the interrupt path introduces a considerable
    performance penalty for networking ~ 14% on iperf.
    
    This commit restores uml to a stable state until a better
    solution is found.
    Signed-off-by: default avatarAnton Ivanov <anton.ivanov@cambridgegreys.com>
    Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
    5c2ffce1
Kconfig 5.12 KB