powerpc/perf: Fix IMC allocation routine

Michael Ellerman patch-notifications at ellerman.id.au
Wed Nov 1 16:17:42 AEDT 2017

On Thu, 2017-10-19 at 19:41:33 UTC, "Guilherme G. Piccoli" wrote:
> When setting nr_cpus=1, we observed a crash in IMC code during boot
> due to a missing allocation: basically, IMC code is taking the number
> of threads into account in imc_mem_init() and if we manually set
> nr_cpus for a value that is not multiple of the number of threads per
> core, an integer division in that function will discard the decimal
> portion, leading IMC to not allocate one mem_info struct. This causes
> a NULL pointer dereference later, on is_core_imc_mem_inited().
> This patch just rounds that division up, fixing the bug.
> Signed-off-by: Guilherme G. Piccoli <gpiccoli at linux.vnet.ibm.com>

Applied to powerpc fixes, thanks.



More information about the Linuxppc-dev mailing list