Re: JITs and 52-bit VA
From: Kirill A. Shutemov <hidden>
Date: 2016-06-22 20:24:18
On Wed, Jun 22, 2016 at 11:17:54PM +0300, Cyrill Gorcunov wrote:
On Wed, Jun 22, 2016 at 12:56:56PM -0700, Dave Hansen wrote:quoted
Yeah, cgroups don't make a lot of sense. On x86, the 48-bit virtual address is even hard-coded in the ABI[1]. So we can't change *any* program's layout without either breaking the ABI or having it opt in. But, we're also lucky to only have one VA layout since day one. 1. www.x86-64.org/documentation/abi.pdf - a??... Therefore, conforming processes may only use addresses from 0x00000000 00000000 to 0x00007fff ffffffff .a??Yes, but noone forces you to write conforming programs ;) After all while hw allows you to run VA with bits > than 48 it's fine, all side effects of breaking abi is up to program author (iirc on x86 there is up to 52 bits on hw level allowed, don't have specs under my hands?)
Nope. 48-bit VA (47-bit to userspace) and 46-bit PA. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>