Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1338408

Re: [PATCH] x86/mm/pkeys: Do not enable them by default

Show all headers | View raw

On Fri, Feb 19, 2016 at 09:49:02AM -0800, Dave Hansen wrote:
> For gains that small, we should barely even allow this thing to be
> configurable, much less default it to off.

Well, it's not about size gains only - it is also about adding code to
the kernel which is never going to be executed and also building it each
time on !pkey machines.

> Yes, agreed.  Distros _can_ override things.  But, In general,
> *especially* with user-visible effects, I'd really like defconfig (or
> other build defaults) to be reasonably close to what distributions do.

You can always add it to arch/x86/configs/x86_64_defconfig.

> My view has always been that the folks that really care about binary
> size are the ones that will be the ones digging through their .configs
> turning things off.

Except when automating "make oldconfig" and then wondering why all of a
sudden new features are enabled.

In my experience, it has always been the case that new features are
default off. What you want to achieve can easily be done without the
"def_bool y" thing.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 00/33] x86: Memory Protection Keys (v10) Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
  [PATCH 18/33] x86, mm: simplify get_user_pages() PTE bit handling Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/mm/gup: Simplify get_user_pages()   PTE bit handling tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 23/33] x86, pkeys: dump PKRU with other kernel registers Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/mm/pkeys:   Dump PKRU with other kernel registers tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 30/33] x86, fpu: allow setting of XSAVE state Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/fpu: Allow setting of XSAVE state tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 03/33] mm, gup: switch callers of get_user_pages() to not pass tsk/mm Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] mm/gup: Switch all callers of get_user_pages()   to not pass tsk/mm tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 19/33] x86, pkeys: check VMAs and PTEs for protection keys Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] mm/gup, x86/mm/pkeys:   Check VMAs and PTEs for protection keys tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 26/33] x86, pkeys: actually enable Memory Protection Keys in CPU Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/mm/pkeys:   Actually enable Memory Protection Keys in the CPU tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 07/33] x86, pkeys: define new CR4 bit Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/cpu, x86/mm/pkeys: Define new CR4 bit tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 13/33] x86, pkeys: pass VMA down in to fault signal generation code Dave Hansen <dave@sr71.net> - 2016-02-12 22:10 +0100
    [tip:mm/pkeys] x86/mm/pkeys:   Pass VMA down in to fault signal generation code tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 11/33] x86, pkeys: store protection in high VMA flags Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    [tip:mm/pkeys] mm/core, x86/mm/pkeys:   Store protection bits in high VMA flags tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:30 +0100
  [PATCH 10/33] x86, pkeys: new page fault error code bit: PF_PK Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    [tip:mm/pkeys] x86/mm/pkeys: Add new 'PF_PK'   page fault error code bit tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 09/33] x86, pkeys: PTE bits for storing protection key Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    [tip:mm/pkeys] x86/mm/pkeys:   Add PTE bits for storing protection key tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 06/33] x86, pkeys: cpuid bit definition Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    [tip:mm/pkeys] x86/cpufeature, x86/mm/pkeys:   Add protection keys related CPUID definitions tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 02/33] mm: overload get_user_pages() functions Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    Re: [PATCH 02/33] mm: overload get_user_pages() functions Ingo Molnar <mingo@kernel.org> - 2016-02-16 09:40 +0100
      Re: [PATCH 02/33] mm: overload get_user_pages() functions Dave Hansen <dave@sr71.net> - 2016-02-17 19:20 +0100
    [tip:mm/pkeys] mm/gup: Overload get_user_pages() functions tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
  [PATCH 01/33] mm: introduce get_user_pages_remote() Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Balbir Singh <bsingharora@gmail.com> - 2016-02-15 07:10 +0100
      Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Dave Hansen <dave@sr71.net> - 2016-02-15 17:30 +0100
    Re: [PATCH 01/33] mm: introduce get_user_pages_remote() Srikar Dronamraju <srikar@linux.vnet.ibm.com> - 2016-02-15 07:20 +0100
    [tip:x86/pkeys] mm/gup: Introduce get_user_pages_remote() tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-16 13:20 +0100
      Re: [tip:x86/pkeys] mm/gup: Introduce get_user_pages_remote() Konstantin Khlebnikov <koct9i@gmail.com> - 2016-02-20 07:30 +0100
  [PATCH 05/33] x86, pkeys: Add Kconfig option Dave Hansen <dave@sr71.net> - 2016-02-12 22:20 +0100
    [tip:mm/pkeys] x86/mm/pkeys: Add Kconfig option tip-bot for Dave Hansen <tipbot@zytor.com> - 2016-02-18 21:20 +0100
      [PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 12:30 +0100
        Re: [PATCH] x86/mm/pkeys: Do not enable them by default Dave Hansen <dave@sr71.net> - 2016-02-19 18:20 +0100
          Re: [PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 18:30 +0100
            Re: [PATCH] x86/mm/pkeys: Do not enable them by default Dave Hansen <dave@sr71.net> - 2016-02-19 18:50 +0100
              Re: [PATCH] x86/mm/pkeys: Do not enable them by default Borislav Petkov <bp@alien8.de> - 2016-02-19 19:40 +0100
  Re: [PATCH 00/33] x86: Memory Protection Keys (v10) Ingo Molnar <mingo@kernel.org> - 2016-02-16 10:30 +0100

csiph-web