Am 29.05.22 um 22:33 schrieb Heiko Carstens: [...]
Guess the patch below on top of your patch is what we want. Just for clarification: if gmap is not NULL then the process is a kvm process. So, depending on the workload, this optimization makes sense. diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 4608cc962ecf..e1d40ca341b7 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -436,12 +436,11 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)/* The fault is fully completed (including releasing mmap lock) */if (fault & VM_FAULT_COMPLETED) { - /* - * Gmap will need the mmap lock again, so retake it. TODO: - * only conditionally take the lock when CONFIG_PGSTE set. - */ - mmap_read_lock(mm); - goto out_gmap; + if (gmap) { + mmap_read_lock(mm); + goto out_gmap; + } + goto out;
Yes, that makes sense. With that Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>