Messages in this thread | | | Date | Fri, 16 Nov 2012 13:32:22 -0800 | From | "H. Peter Anvin" <> | Subject | Re: Wrong defaults in 3.7-rc3 |
| |
On 11/15/2012 03:06 AM, Pavel Machek wrote: > Hi! > > Supervisor Mode Access Prevention (X86_SMAP) [Y/n/?] (NEW) > > ...Slows stuff down, eats memory, only works on unreleased Intel CPUs > (from 2013!) perhaps should be off by default? > > "Supervisor Mode Access Prevention (SMAP) is a security > feature in newer Intel processors. There is a small > performance cost if this enabled and turned on; there is > also a small increase in the kernel size if this is enabled." >
*Extremely* small. Unless you are targeting a specific processor there is no point in disabling it. If anyone can find a non-SMAP processor on which the overhead is measurable I would be highly surprised, except perhaps some embedded 486 clone.
-hpa
| |