On Fri, 21 Apr 2006, Zoltan Menyhart wrote: > - it scales well mmap_sem is the major performance bottleneck for page faults at this time because it creates a bouncing cacheline. Figure out a way to avoid that to increase performance. > 4. On one hand, as "free_pgtables()" cannot run in the mean time, > there is no need to re-read pgd[i] -> pud[j] -> pmd[k]. > On the other hand, the swapper is not excluded => we keep re-checking > pte[l] and purging the freshly inserted TLB entry if it has been changed. The walking of pgd/pud/pmd can happen anytime through the mmu on many architectures. It is therefore not protectable by any lock. free_pgtables() is run when all processes in a mm_struct have terminated or when all vmas from an area have been removed. There can be no one using the page tables. - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|