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Re: [PATCH] Add Prefer_MAP_32BIT_EXEC for Silvermont
- From: Zack Weinberg <zackw at panix dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Andi Kleen <andi at firstfloor dot org>, Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 11 Dec 2015 16:35:09 -0500
- Subject: Re: [PATCH] Add Prefer_MAP_32BIT_EXEC for Silvermont
- Authentication-results: sourceware.org; auth=none
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On Fri, Dec 11, 2015 at 4:25 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Dec 11, 2015 at 1:16 PM, Zack Weinberg <zackw@panix.com> wrote:
>>
>>> Also 3% (likely more in other workloads) is a significant performance
>>> difference, especially when we're talking about something as common as
>>> function calls.
>>
>> I saw a claim of 3% *overall* performance increase on an artificial
>> benchmark and that's all. I currently suspect this will turn out to
>> be unmeasurable on realistic workloads.
>
> 3% speedup is for my typical workloads, which is running GCC.
You can opt in in your development environment; equally you can switch
ASLR off altogether.
The "realistic workloads" I care about are long-lived network clients
and servers -- you know, the things for which ASLR is relevant as a
security measure.
zw