On 05/16/2014 11:35 AM, Oleg Nesterov wrote: > On 05/16, Sasha Levin wrote: >> >> On 04/13/2014 03:56 PM, Oleg Nesterov wrote: >>> 1. Remove CLONE_KERNEL, it has no users and it is dangerous. >>> >>> The (old) comment says "List of flags we want to share for kernel >>> threads" but this is not true, we do not want to share ->sighand by >>> default. This flag can only be used if the caller is sure that both >>> parent/child will never play with signals (say, allow_signal/etc). >>> >>> 2. Change rest_init() to clone kernel_init() without CLONE_SIGHAND. >>> >>> In this case CLONE_SIGHAND does not really hurt, and it looks like >>> optimization because copy_sighand() can avoid kmem_cache_alloc(). >>> >>> But in fact this only adds the minor pessimization. kernel_init() >>> is going to exec the init process, and de_thread() will need to >>> unshare ->sighand and do kmem_cache_alloc(sighand_cachep) anyway, >>> but it needs to do more work and take tasklist_lock and siglock. >>> >>> Signed-off-by: Oleg Nesterov <[email protected]> >> >> Hi Oleg, >> >> This patch triggers a hang during boot in my KVM guest. > > Hmm... How??? ;)
I'm afraid this is just bisection gone bad. The real issue was the new goldfish code added, and not this patch. Since apparently the boot issue was probabilistic I ended up blaming this commit by mistake. Sorry about that. Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
