On 06/24/22 at 02:37pm, Valentin Schneider wrote: > On 24/06/22 09:30, Baoquan He wrote: > > On 06/20/22 at 12:15pm, Valentin Schneider wrote: > >> @@ -94,14 +94,20 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments, > >> /* > >> * Because we write directly to the reserved memory region when loading > >> * crash kernels we need a mutex here to prevent multiple crash kernels > >> - * from attempting to load simultaneously, and to prevent a crash kernel > >> - * from loading over the top of a in use crash kernel. > >> - * > >> - * KISS: always take the mutex. > >> + * from attempting to load simultaneously. > >> */ > >> if (!mutex_trylock(&kexec_mutex)) > >> return -EBUSY; > > > > So kexec_mutex is degenerated to only avoid simultaneous loading, > > should we rename to reflect that?, e.g kexec_load_mutex. > > > > It's also serializing crash_get_memory_size() and crash_shrink_memory(); > more generally it should still be the preferred serialization mechanism as > it's a "proper" lock visible by instrumentation, the atomic variable is a > side character for the NMI case. You are right. I only checked the code comment in this place. Then this patch looks good to me, thx. Acked-by: Baoquan He <bhe@xxxxxxxxxx> _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
