Debugging SIGBUS on x86 Linux

Question

What can cause SIGBUS (bus error) on a generic x86 userland application in Linux? All of the discussion I\'ve been able to find online is regarding memory alignment errors,

Answer 1

If you request a mapping backed by hugepages with mmap and the MAP_HUGETLB flag, you can get SIGBUS if the kernel runs out of allocated huge pages and thus cannot handle a page fault.

In this case, you'll need to raise the number of allocated huge pages via

• /sys/kernel/mm/hugepages/hugepages-/nr_hugepages or
• /sys/devices/system/node/nodeX/hugepages/hugepages-/nr_hugepages on NUMA systems.