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Message-ID: <20210625145041.GA29722@xsang-OptiPlex-9020>
Date: Fri, 25 Jun 2021 22:50:41 +0800
From: Oliver Sang <oliver.sang@...el.com>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: LKML <linux-kernel@...r.kernel.org>,
Andy Lutomirski <luto@...nel.org>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Fenghua Yu <fenghua.yu@...el.com>,
Tony Luck <tony.luck@...el.com>,
Yu-cheng Yu <yu-cheng.yu@...el.com>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
Borislav Petkov <bp@...e.de>,
Peter Zijlstra <peterz@...radead.org>,
Kan Liang <kan.liang@...ux.intel.com>,
Chang Seok Bae <chang.seok.bae@...el.com>,
Megha Dey <megha.dey@...ux.intel.com>, aubrey.li@...el.com,
zhengjun.xing@...ux.intel.com, feng.tang@...el.com,
yujie.liu@...el.com, beibei.si@...el.com, philip.li@...el.com,
julie.du@...el.com
Subject: Re: [patch V4 00/65] x86/fpu: Spring cleaning and PKRU sanitizing
Hi Thomas,
On Wed, Jun 23, 2021 at 02:01:27PM +0200, Thomas Gleixner wrote:
> The main parts of this series are:
>
> - Simplification and removal/replacement of redundant and/or
> overengineered code.
>
> - Name space cleanup as the existing names were just a permanent source
> of confusion.
>
> - Clear seperation of user ABI and kernel internal state handling.
>
> - Removal of PKRU from being XSTATE managed in the kernel because PKRU
> has to be eagerly restored on context switch and keeping it in sync
> in the xstate buffer is just pointless overhead and fragile.
>
> The kernel still XSAVEs PKRU on context switch but the value in the
> buffer is not longer used and never restored from the buffer.
>
> This still needs to be cleaned up, but the series is already 40+
> patches large and the cleanup of this is not a functional problem.
>
> The functional issues of PKRU management are fully addressed with the
> series as is.
>
> - Cleanup of fpu signal restore
>
> - Make the fast path self contained. Handle #PF directly and skip
> the slow path on any other exception as that will just end up
> with the same result that the frame is invalid. This allows
> the compiler to optimize the slow path out for 64bit kernels
> w/o ia32 emulation.
>
> - Reduce code duplication and unnecessary operations
>
> It applies on top of
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master
>
> and is also available via git:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git x86/fpu
0-Day kernel CI tested this branch from performance view, choosing some sub-tests
from will-it-scale and stress-ng (detail as below)
Test Summary
============
no obvious performance changes found vs v5.13-rc7 so far
Test Environment
================
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git/log/?h=x86/fpu
* a263e30a4f111 (tglx-devel/x86/fpu) x86/fpu/signal: Let xrstor handle the features to init
* cf917e53a97e9 x86/fpu/signal: Handle #PF in the direct restore path
* 7b269dff0be66 x86/fpu: Return proper error codes from user access functions
* d2d6be9e16386 x86/fpu/signal: Split out the direct restore code
...
* d3ca29fb9911f x86/fpu: Fix copy_xstate_to_kernel() gap handling
* 58a664af246e6 Merge branch 'x86/fpu' of ../tip into x86/fpu
|\
| * b7c11876d24bd (tip/x86/fpu, peterz-queue/x86/fpu) selftests/x86: Test signal frame XSTATE header corruption handling
...
* | 13311e74253fe (tag: v5.13-rc7
64bit kernel testing, upon below platforms:
(1)
model: Cascade Lake
Intel(R) Xeon(R) Gold 6238M CPU @ 2.10GHz
nr_node: 2
nr_cpu: 88
memory: 128G
(2)
model: Ice Lake
nr_node: 2
nr_cpu: 96
memory: 256G
32bit kernel testing, upon below platform:
Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz
model: Ivy Bridge
nr_node: 1
nr_cpu: 8
memory: 16G
tested below test suites:
will-it-scale-performance-context_switch1
will-it-scale-performance-page_fault1
will-it-scale-performance-poll1
will-it-scale-performance-pthread_mutex1
will-it-scale-performance-writeseek1
regarding stress-ng, either no gap or data is unstable on
64bit (1) platform
commit:
v5.13-rc7
a263e30a4f111e13a6c859102d1b319a79b072c0
v5.13-rc7 a263e30a4f111e13a6c859102d1
---------------- ---------------------------
%stddev %change %stddev
\ | \
2.786e+08 ± 2% -1.3% 2.751e+08 stress-ng.switch.ops
4643776 ± 2% -1.3% 4585061 stress-ng.switch.ops_per_sec
--
25884344 ± 15% +5.3% 27252860 ± 12% stress-ng.nanosleep.ops
431397 ± 15% +5.3% 454204 ± 12% stress-ng.nanosleep.ops_per_sec
--
5.48e+09 ± 2% +4.3% 5.713e+09 ± 3% stress-ng.yield.ops
91326562 ± 2% +4.3% 95215138 ± 3% stress-ng.yield.ops_per_sec
--
6723205 ± 3% -2.0% 6585690 ± 9% stress-ng.tee.ops
112049 ± 3% -2.0% 109755 ± 9% stress-ng.tee.ops_per_sec
--
3078530 -0.2% 3072610 stress-ng.zombie.ops
49390 -0.2% 49295 stress-ng.zombie.ops_per_sec
--
2261601 -0.1% 2259339 stress-ng.cyclic.ops
37693 -0.1% 37655 stress-ng.cyclic.ops_per_sec
--
1.543e+09 ± 16% +0.4% 1.55e+09 ± 19% stress-ng.fifo.ops
25721633 ± 16% +0.4% 25831339 ± 19% stress-ng.fifo.ops_per_sec
--
192171 +0.6% 193383 stress-ng.clone.ops
2998 +0.6% 3016 stress-ng.clone.ops_per_sec
--
88703410 -0.5% 88257268 stress-ng.sleep.ops
1470841 -0.5% 1463509 stress-ng.sleep.ops_per_sec
--
401598 +0.1% 401990 stress-ng.netlink-proc.ops
6692 +0.1% 6699 stress-ng.netlink-proc.ops_per_sec
--
1.182e+08 +2.5% 1.212e+08 stress-ng.softlockup.ops
1969636 +2.5% 2019730 stress-ng.softlockup.ops_per_sec
--
1.866e+08 -0.2% 1.863e+08 stress-ng.fanotify.ops
4754116 ± 12% -2.8% 4620280 ± 5% stress-ng.fanotify.ops_per_sec
--
17926280 -0.3% 17866738 stress-ng.vforkmany.ops
286256 +0.4% 287262 stress-ng.vforkmany.ops_per_sec
--
1.381e+09 ± 13% +8.7% 1.501e+09 ± 19% stress-ng.fifo.ops
23013090 ± 13% +8.7% 25020209 ± 19% stress-ng.fifo.ops_per_sec
--
1.165e+08 ± 2% -2.0% 1.141e+08 ± 3% stress-ng.splice.ops
1941398 ± 2% -2.0% 1901755 ± 3% stress-ng.splice.ops_per_sec
--
5476091 -0.2% 5466962 stress-ng.vfork.ops
91262 -0.2% 91116 stress-ng.vfork.ops_per_sec
--
21878786 -1.4% 21574984 stress-ng.netlink-task.ops
364646 -1.4% 359582 stress-ng.netlink-task.ops_per_sec
--
5023286 +1.6% 5101458 stress-ng.pthread.ops
83554 +1.6% 84869 stress-ng.pthread.ops_per_sec
--
92688395 ± 2% -8.3% 84967931 ± 4% stress-ng.futex.ops
1544792 ± 2% -8.3% 1416117 ± 4% stress-ng.futex.ops_per_sec
--
5416582 ± 2% +1.6% 5504734 ± 5% stress-ng.wait.ops
90275 ± 2% +1.6% 91744 ± 5% stress-ng.wait.ops_per_sec
--
7.939e+08 ± 4% +0.7% 7.998e+08 stress-ng.mq.ops
13231931 ± 4% +0.7% 13329018 stress-ng.mq.ops_per_sec
--
3.936e+08 ± 53% +51.5% 5.965e+08 ± 37% stress-ng.hrtimers.ops
6416615 ± 52% +49.8% 9609730 ± 38% stress-ng.hrtimers.ops_per_sec
--
35268682 -1.1% 34872339 stress-ng.sendfile.ops
587805 -1.1% 581200 stress-ng.sendfile.ops_per_sec
--
18126587 -0.7% 18000304 ± 3% stress-ng.sem-sysv.ops
302108 -0.7% 300004 ± 3% stress-ng.sem-sysv.ops_per_sec
--
9.953e+08 ± 2% -0.4% 9.912e+08 stress-ng.pipe.ops
16589030 ± 2% -0.4% 16519202 stress-ng.pipe.ops_per_sec
--
1056000 +0.0% 1056000 stress-ng.schedpolicy.ops
17599 +0.0% 17599 stress-ng.schedpolicy.ops_per_sec
--
2.481e+09 +1.2% 2.51e+09 stress-ng.vm-splice.ops
41349053 +1.2% 41828864 stress-ng.vm-splice.ops_per_sec
--
56805932 ± 2% +1.1% 57451245 ± 2% stress-ng.eventfd.ops
946751 ± 2% +1.1% 957505 ± 2% stress-ng.eventfd.ops_per_sec
--
1605 -1.2% 1585 ± 2% stress-ng.mmapfork.ops
25.18 ± 4% -0.8% 24.98 ± 4% stress-ng.mmapfork.ops_per_sec
--
2549139 +1.2% 2578537 stress-ng.fork.ops
42485 +1.2% 42975 stress-ng.fork.ops_per_sec
--
16582541 ± 3% -10.8% 14792067 ± 21% stress-ng.close.ops
276357 ± 3% -10.8% 246515 ± 21% stress-ng.close.ops_per_sec
--
1.847e+09 -1.3% 1.822e+09 stress-ng.pipeherd.ops
30743202 -1.3% 30330538 stress-ng.pipeherd.ops_per_sec
--
6780757 ± 2% +4.3% 7070424 stress-ng.tee.ops
113008 ± 2% +4.3% 117835 stress-ng.tee.ops_per_sec
--
3421466 +0.0% 3422853 stress-ng.dnotify.ops
57024 +0.0% 57047 stress-ng.dnotify.ops_per_sec
--
749895 -0.9% 742801 stress-ng.kill.ops
12498 -0.9% 12379 stress-ng.kill.ops_per_sec
--
3.761e+08 -2.5% 3.668e+08 stress-ng.msg.ops
6266833 -2.5% 6112949 stress-ng.msg.ops_per_sec
--
2258479 +0.1% 2260255 stress-ng.daemon.ops
37641 +0.1% 37670 stress-ng.daemon.ops_per_sec
--
40560445 -0.8% 40239283 stress-ng.affinity.ops
668138 -1.6% 657142 stress-ng.affinity.ops_per_sec
--
21230 ± 4% -0.9% 21047 ± 2% stress-ng.inotify.ops
353.14 ± 4% -0.9% 349.88 ± 2% stress-ng.inotify.ops_per_sec
--
23250444 ± 2% +1.6% 23627954 stress-ng.fault.ops
387495 ± 2% +1.6% 393795 stress-ng.fault.ops_per_sec
--
3.94e+08 -0.2% 3.933e+08 stress-ng.sem.ops
6567438 -0.2% 6555371 stress-ng.sem.ops_per_sec
--
698544 -0.0% 698480 stress-ng.session.ops
11494 +0.0% 11495 stress-ng.session.ops_per_sec
>
> This is a follow up to V3 which can be found here:
>
> https://lore.kernel.org/r/20210618141823.161158090@linutronix.de
>
> Changes vs. V3:
>
> - Dropped the two bugfixes which are applied already and rebased on top
>
> - Addressed review comments (Andy, Boris)
>
> Patches: 13, 35, 36, 37, 46, 58, 62, 63
>
> - Fixed the math-emu fallout which I had stashed safely on the 32bit
> testbox (Boris)
>
> Patch: 28
>
> - Picked up tags
>
> Thanks to everyone for review, feedback and testing (various teams
> @Intel).
>
> Note: I've not picked up any tested-by tags. It would be nice to have
> them on this hopefully final version.
>
> Thanks,
>
> tglx
> ---
> arch/x86/events/intel/lbr.c | 6
> arch/x86/include/asm/fpu/internal.h | 202 ++++------
> arch/x86/include/asm/fpu/xstate.h | 78 +++-
> arch/x86/include/asm/pgtable.h | 57 ---
> arch/x86/include/asm/pkeys.h | 9
> arch/x86/include/asm/pkru.h | 62 +++
> arch/x86/include/asm/processor.h | 9
> arch/x86/include/asm/special_insns.h | 14
> arch/x86/kernel/cpu/common.c | 34 -
> arch/x86/kernel/fpu/core.c | 282 +++++++--------
> arch/x86/kernel/fpu/init.c | 15
> arch/x86/kernel/fpu/regset.c | 223 ++++++------
> arch/x86/kernel/fpu/signal.c | 419 ++++++++++------------
> arch/x86/kernel/fpu/xstate.c | 645 +++++++++++++----------------------
> arch/x86/kernel/process.c | 22 +
> arch/x86/kernel/process_64.c | 28 +
> arch/x86/kernel/traps.c | 5
> arch/x86/kvm/svm/sev.c | 1
> arch/x86/kvm/x86.c | 56 +--
> arch/x86/math-emu/fpu_proto.h | 2
> arch/x86/math-emu/load_store.c | 2
> arch/x86/math-emu/reg_ld_str.c | 2
> arch/x86/mm/extable.c | 2
> arch/x86/mm/fault.c | 2
> arch/x86/mm/pkeys.c | 22 -
> include/linux/pkeys.h | 4
> 26 files changed, 1037 insertions(+), 1166 deletions(-)
>
>
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