Re: iov_kunit_copy_to_kvec: ASSERTION FAILED at lib/tests/kunit_iov_iter.c:63, Expected got == npages, but, got == 1 (0x1), npages == 256 (0x100) (v7.0.2, ppc)

[Erhard Furtner]

This happens in alloc_pages_bulk_noprof(), due to

        pcp = pcp_spin_trylock(zone->per_cpu_pageset);
        if (!pcp)
                goto failed;

Because:

#ifdef CONFIG_SMP
[...]
/*
   * On CONFIG_SMP=n the UP implementation of spin_trylock() never fails
and thus
   * is not compatible with our locking scheme. However we do not need
pcp for
   * scalability in the first place, so just make all the trylocks fail
and take
   * the slow path unconditionally.
   */
#else
#define pcp_spin_trylock(ptr)           \
                NULL


So apparently it is expected that alloc_pages_bulk() returns 1 on non-SMP.

Christophe

I got SMP set as my G4 DP got 2 x 7450 cpus.

I can attach full kernel .config when I return on Saturday.

Regards,
Erhard