One might well wonder why the kernel hackers are trying to put this sort of change into a stable kernel series. The problem with 8KB stacks is that they require an "order 1" memory allocation: two pages which are contiguous in physical memory. Order 1 allocations can be very hard to satisfy once the system has been running for a while; physical memory can become so fragmented that two adjacent free pages simply do not exist. The kernel will try hard to free up pages to satisfy larger allocations; the result can be a slow, painful, thrashing system.
[^] # Re: Pourquoi 4k?
Posté par Pierre . En réponse à la dépêche Nouveaux pilotes nvidia 6106. Évalué à 3.
One might well wonder why the kernel hackers are trying to put this sort of change into a stable kernel series. The problem with 8KB stacks is that they require an "order 1" memory allocation: two pages which are contiguous in physical memory. Order 1 allocations can be very hard to satisfy once the system has been running for a while; physical memory can become so fragmented that two adjacent free pages simply do not exist. The kernel will try hard to free up pages to satisfy larger allocations; the result can be a slow, painful, thrashing system.