On Thu, Aug 29, 2024 at 06:56:11PM +0200, David Hildenbrand wrote: > +#ifdef CONFIG_MM_ID > +/* > + * For init_mm and friends, we don't allocate an ID and use the dummy value > + * instead. Limit ourselves to 1M MMs for now: even though we might support > + * up to 4M PIDs, having more than 1M MM instances is highly unlikely. > + */ Hm. Should we lower PID_MAX_LIMIT limit then? Also, do we really need IDA? Can't we derive the ID from mm_struct address? > +#define MM_ID_DUMMY 0 > +#define MM_ID_NR_BITS 20 > +#define MM_ID_MIN (MM_ID_DUMMY + 1) > +#define MM_ID_MAX ((1U << MM_ID_NR_BITS) - 1) > +#endif /* CONFIG_MM_ID */ > + > #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ > MT_FLAGS_USE_RCU) > extern struct mm_struct init_mm; -- Kiryl Shutsemau / Kirill A. Shutemov
