[PATCH v3 1/2] lib: sbi_init: Avoid thundering hurd problem with coldboot_lock

Sean Anderson seanga2 at gmail.com
Wed Aug 19 08:03:32 EDT 2020


On 8/18/20 12:07 AM, Anup Patel wrote:
> We can have thundering hurd problem with coldboot_lock where the
> boot HART can potentially starve trying to acquire coldboot_lock
> because some of the non-boot HARTs are continuously acquiring and
> releasing coldboot_lock. This can happen if MIP.MSIP bit is already
> set for some of the non-boot HARTs.
> 
> To avoid thundering hurd problem for coldboot_lock, we use the
> __smp_load_acquire() and __smp_store_release() for coldboot_done
> flag and use coldboot_lock only for coldboot_wait_hmask.
> 
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> Tested-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Reviewed-by: Atish Patra <atish.patra at wdc.com>

Just curious, what are the changes from v1 and v2?

--Sean



More information about the opensbi mailing list