3 ms·
They do... each allocation that is protecting must be aligned by 4kb, and now by 16kb (ideally padded at end) On top of that, adding 4kb (or 16kb) pages sprink
by malkia 1y ago
They do... each allocation that is protecting must be aligned by 4kb, and now by 16kb (ideally padded at end)
On top of that, adding 4kb (or 16kb) pages sprinkled across adds more to the TLB cache.
- junon 1y agoGuard pages do not require physical pages, no. Just a page table entry. All pages are aligned by 4kib (except for esoteric CPUs perhaps). That's what a page is. Unless the guard page is on another page table boundary, no additional physical pages are required. Further, TLB cost means nothing if it's a guard page. It shouldn't be accessed in any normal path barring a bug.
- malkia 1y agoWhat I'm saying is that if you have relatively lots of small allocations, with the 4Kb page, they also have to be aligned by 4kb, and with the new android changes - it'll be 16kb (e.g. 4x more).