[tip:x86/fpu] x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()

Commit-ID: 39388e80f9b0c3788bfb6efe3054bdce0c3ead45 Gitweb: https://git.kernel.org/tip/39388e80f9b0c3788bfb6efe3054bdce0c3ead45 Author: Sebastian Andrzej Siewior AuthorDate: Wed, 3 Apr 2019 18:41:35 +0200 Committer: Borislav Petkov CommitDate: Wed, 10 Apr 2019 14:46:35 +0200 x86/fpu

[tip:x86/fpu] x86/fpu: Always init the state in fpu__clear()

Commit-ID: 88f5260a3bf9bfb276b5b4aac2e81587e425a1d7 Gitweb: https://git.kernel.org/tip/88f5260a3bf9bfb276b5b4aac2e81587e425a1d7 Author: Sebastian Andrzej Siewior AuthorDate: Wed, 3 Apr 2019 18:41:33 +0200 Committer: Borislav Petkov CommitDate: Tue, 9 Apr 2019 19:28:06 +0200 x86/fpu

[tip:x86/fpu] x86/fpu: Remove preempt_disable() in fpu__clear()

Commit-ID: 60e528d6ce3f60a058bbb64f8acb2a07f84b172a Gitweb: https://git.kernel.org/tip/60e528d6ce3f60a058bbb64f8acb2a07f84b172a Author: Sebastian Andrzej Siewior AuthorDate: Wed, 3 Apr 2019 18:41:32 +0200 Committer: Borislav Petkov CommitDate: Tue, 9 Apr 2019 19:27:46 +0200 x86/fpu

[tip:x86/fpu] x86/fpu: Remove fpu__restore()

Commit-ID: 6dd677a044e606fd343e31c2108b13d74aec1ca5 Gitweb: https://git.kernel.org/tip/6dd677a044e606fd343e31c2108b13d74aec1ca5 Author: Sebastian Andrzej Siewior AuthorDate: Wed, 3 Apr 2019 18:41:31 +0200 Committer: Borislav Petkov CommitDate: Tue, 9 Apr 2019 19:27:42 +0200 x86/fpu

[tip:x86/fpu] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig()

Commit-ID: 39ea9baffda91df8bfee9b45610242a3191ea1ec Gitweb: https://git.kernel.org/tip/39ea9baffda91df8bfee9b45610242a3191ea1ec Author: Sebastian Andrzej Siewior AuthorDate: Wed, 3 Apr 2019 18:41:30 +0200 Committer: Borislav Petkov CommitDate: Tue, 9 Apr 2019 19:27:29 +0200 x86/fpu

[ANNOUNCE] v5.0.7-rt5

Dear RT folks! I'm pleased to announce the v5.0.7-rt5 patch set. Changes since v5.0.7-rt4: - Update "x86: load FPU registers on return to userland" from v7 to v9. - Update "clocksource: improve Atmel TCB timer driver" from v7 to latest post by Alexandre Belloni. I hope this works,

Re: [PATCH 24/27] x86/fpu: Add a fastpath to __fpu__restore_sig()

On 2019-04-12 19:17:59 [+0200], Borislav Petkov wrote: > > @@ -327,7 +327,19 @@ static int __fpu__restore_sig(void __user *buf, void > > __user *buf_fx, int size) > > if (ret) > > goto err_out; > > envp = > > + } else { > > I've added here: I would

Re: [PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace

On 2019-04-12 18:48:28 [+0200], Borislav Petkov wrote: > On Fri, Apr 12, 2019 at 06:37:41PM +0200, Sebastian Andrzej Siewior wrote: > > (as you mentioned) so we would always record both trace points. > > Therefore I would suggest to remove it. > > Remove which one? remove x

Re: [PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace

On 2019-04-12 18:22:13 [+0200], Borislav Petkov wrote: > On Fri, Apr 12, 2019 at 05:24:37PM +0200, Sebastian Andrzej Siewior wrote: > > Isn't it called from fpu__clear()? > > $ git grep trace_x86_fpu_activate_state > $ > > all 23 patches applied. Grepping the la

Re: [PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace

On 2019-04-12 16:36:15 [+0200], Borislav Petkov wrote: > On Wed, Apr 03, 2019 at 06:41:52PM +0200, Sebastian Andrzej Siewior wrote: > > @@ -226,10 +236,9 @@ static void fpu__initialize(struct fpu *fpu) > > { > > WARN_ON_FPU(fpu != >thread.fpu); > > > > +

Re: [PATCH 12/27] x86/pkru: Provide .*_pkru_ins() functions

On 2019-04-10 18:52:41 [+0200], Borislav Petkov wrote: > On Wed, Apr 10, 2019 at 06:36:15PM +0200, Borislav Petkov wrote: > > Well, this is going in the wrong direction. The proper thing to do would > > be to have: > > > > rdpkru() > > wrpkru() > > > > which only do the inline asm with the

[PATCH RT] bpf: Guard bpf_prog_active with a locallock

The bpf_prog_active counter is used to avoid recursion on the same CPU. On RT we can't keep it with the preempt-disable part because the syscall may need to acquire locks or allocate memory. Use a locallock() to avoid recursion on the same CPU. Signed-off-by: Sebastian Andrzej Siewior

Re: [PATCH 2/2] sched: Distangle worker accounting from rq lock

On 2019-04-08 12:45:05 [-0700], Tejun Heo wrote: > Hello, Hi, … > This looks good from wq side. Peter, are you okay with routing this > through the wq tree? If you wanna take it through the sched tree, > please feel free to add Thank you. > Acked-by: Tejun Heo > > Thanks. Sebastian

Re: [PATCH 19/27] x86/fpu: Update xstate's PKRU value on write_pkru()

On 2019-04-08 11:14:28 [-0700], Dave Hansen wrote: > On 4/3/19 9:41 AM, Sebastian Andrzej Siewior wrote: > > During the context switch the xstate is loaded which also includes the > > PKRU value. > > If xstate is restored on return to userland it is required that the >

Re: [PATCH 24/27] x86/fpu: Add a fastpath to __fpu__restore_sig()

On 2019-04-08 19:05:56 [+0200], Thomas Gleixner wrote: > > diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c > > index a5b086ec426a5..f20e1d1fffa29 100644 > > --- a/arch/x86/kernel/fpu/signal.c > > +++ b/arch/x86/kernel/fpu/signal.c > > @@ -242,10 +242,10 @@

Re: [RFC PATCH] arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE state

On 2019-04-05 16:17:50 [+0100], Julien Grall wrote: > Hi, Hi, > > A per-CPU lock? It has to be a raw_spinlock_t because a normal > > spin_lock() / local_lock() would allow scheduling and might be taken as > > part of the context switch or soon after. > raw_spinlock_t would not work here without

Re: [PATCH 1/2] workqueue: Use normal rcu

On 2019-03-22 18:59:23 [+0100], To Tejun Heo wrote: > On 2019-03-22 10:43:34 [-0700], Tejun Heo wrote: > > Hello, Hi, > > We can switch but it doesn't really say why we'd want to. Can you > > please explain why this is better? > > there is this undocumented part. Avoiding the sched RCU means

Re: [RFC PATCH] arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE state

On 2019-04-05 10:02:45 [+0100], Julien Grall wrote: > RT folks already saw this corruption because local_bh_disable() does not > preempt on RT. They are carrying a patch (see "arm64: fpsimd: use > preemp_disable in addition to local_bh_disable()") to disable preemption > along with

[RFC PATCH] random: add a spinlock in addition to get_cpu_var()

age. Should I resend the patch with spinlock_irq_save() instead? Signed-off-by: Sebastian Andrzej Siewior --- drivers/char/random.c | 20 ++-- 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 38c6d1af6d

Re: [PATCH v9 00/27] x86: load FPU registers on return to userland

On 2019-04-04 07:26:37 [-0700], Andy Lutomirski wrote: > I think that David was asking whether we could make kernel_fpu_begin() > regions sometimes be preemptible. The answer is presumably yes, but I > think that should be a separate effort, and it should be justified > with improved performance

Re: [PATCH v9 00/27] x86: load FPU registers on return to userland

On 2019-04-04 14:01:43 [+], David Laight wrote: > From: Sebastian Andrzej Siewior > > Sent: 03 April 2019 17:41 > ... > > To access the FPU registers in kernel we need: > > - disable preemption to avoid that the scheduler switches tasks. By > > doing so

[PATCH] sched: Document that RT task priorities are 1…99

Signed-off-by: Sebastian Andrzej Siewior --- Documentation/scheduler/sched-rt-group.txt | 2 +- include/linux/sched/prio.h | 2 +- kernel/sched/cpupri.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/scheduler/sched-rt

[PATCH v9 00/27] x86: load FPU registers on return to userland

x86/fpu: Always store the registers in copy_fpstate_to_sigframe() x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD x86/fpu: Defer FPU state load until return to userspace Sebastian Andrzej Siewior (22): x86/fpu: Remove fpu->initialized usage in __fpu__restore_s

[PATCH 03/27] x86/fpu: Remove preempt_disable() in fpu__clear()

_fpu_begin() could also force to save FPU's registers after fpu__initialize() without changing the outcome here. Remove the preempt_disable() section in fpu__clear(), preemption here does not hurt. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- arch/x86/kernel/fpu/core.c

[PATCH 06/27] x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()

fpu__clear(). Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 4 1 file changed, 4 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index de83d0ed9e14e..2f044021fde2b 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/ker

[PATCH 02/27] x86/fpu: Remove fpu__restore()

There are no users of fpu__restore() so it is time to remove it. The comment regarding fpu__restore() and TS bit is stale since commit b3b0870ef3ffe ("i387: do not preload FPU state at task switch time") and has no meaning since. Signed-off-by: Sebastian Andrzej Siewior --- Doc

[PATCH 01/27] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig()

ered okay, load it. Should something go wrong, return with an error and without altering the original FPU registers. The removal of "fpu__initialize()" is a nop because fpu->initialized is already set for the user task. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Borislav Petkov -

[PATCH 04/27] x86/fpu: Always init the `state' in fpu__clear()

ime an opcode is emulated. It makes the removal of ->initialized easier if the struct is also initialized in the FPU-less case at the same time. Move fpu__initialize() before the FPU check so it is also performed in the FPU-less case. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav

[PATCH 05/27] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()

pdate the comment to reflect that the "state is always live". Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 35 --- 1 file changed, 8 insertions(+), 27 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/k

[PATCH 08/27] x86/fpu: Remove user_fpu_begin()

_begin() block could set fpu_fpregs_owner_ctx to NULL but a kernel thread does not use user_fpu_begin(). This is a leftover from the lazy-FPU time. Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's content. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- ar

[PATCH 07/27] x86/fpu: Remove fpu->initialized

lid before switch_fpu_finish() is invoked so ->mm is seen of the new task instead the old one. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/ia32/ia32_signal.c | 17 +++ arch/x86/include/asm/fpu/internal.h | 18 arch/x86/include/asm/fpu/types.h| 9 arch/x86/incl

[PATCH 12/27] x86/pkru: Provide .*_pkru_ins() functions

() suffix. __write_pkru() will just invoke __write_pkru_isn() but in a flowup patch will also read back the value. Suggested-by: Dave Hansen Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/pgtable.h | 2 +- arch/x86/include/asm/special_insns.h | 12 +--- arch/x86/kvm

[PATCH 10/27] x86/fpu: Make __raw_xsave_addr() use feature number instead of mask

Most users of __raw_xsave_addr() use a feature number, shift it to a mask and then __raw_xsave_addr() shifts it back to the feature number. Make __raw_xsave_addr() use the feature number as an argument. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- arch/x86/kernel

[PATCH 13/27] x86/fpu: Only write PKRU if it is different from current

Dave Hansen says that the `wrpkru' is more expensive than `rdpkru'. It has a higher cycle cost and it's also practically a (light) speculation barrier. As an optimisation read the current PKRU value and only write the new one if it is different. Signed-off-by: Sebastian Andrzej Siewior

[PATCH 17/27] x86/fpu: Always store the registers in copy_fpstate_to_sigframe()

an earlier version of the patchset while there still was lazy-FPU on x86. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 19 ++- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch

[PATCH 16/27] x86/entry: Add TIF_NEED_FPU_LOAD

-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/internal.h | 6 ++ arch/x86/include/asm/thread_info.h | 2 ++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 82ff84a4c4ab7..b12874b7cf0cf 100644 --- a/arch/x86

[PATCH 19/27] x86/fpu: Update xstate's PKRU value on write_pkru()

During the context switch the xstate is loaded which also includes the PKRU value. If xstate is restored on return to userland it is required that the PKRU value in xstate is the same as the one in the CPU. Save the PKRU in xstate during modification. Signed-off-by: Sebastian Andrzej Siewior

[PATCH 18/27] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD

From: Rik van Riel The FPU registers need only to be saved if TIF_NEED_FPU_LOAD is not set. Otherwise this has been already done and can be skipped. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 12 +++- 1 file changed, 11

[PATCH 20/27] x86/fpu: Inline copy_user_to_fpregs_zeroing()

Start refactoring __fpu__restore_sig() by inlining copy_user_to_fpregs_zeroing(). The orignal function remains and will be used to restore from userland memory if possible. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 20 +++- 1 file changed, 19

[PATCH 14/27] x86/pkeys: Don't check if PKRU is zero before writting it

Andrzej Siewior --- arch/x86/mm/pkeys.c | 7 --- 1 file changed, 7 deletions(-) diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index 05bb9a44eb1c3..50f65fc1b9a3f 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -142,13 +142,6 @@ u32 init_pkru_value = PKRU_AD_KEY( 1

[PATCH 22/27] x86/fpu: Merge the two code paths in __fpu__restore_sig()

s and keep the !ia32_fxstate version. Copy only the user_i387_ia32_struct data structure in the ia32_fxstate. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 146 ++- 1 file changed, 57 insertions(+), 89 deletions(-) diff --git a/arch/x86/

[PATCH 23/27] x86/fpu: Defer FPU state load until return to userspace

gned-off-by: Sebastian Andrzej Siewior --- arch/x86/entry/common.c | 8 +++ arch/x86/include/asm/fpu/api.h | 22 +- arch/x86/include/asm/fpu/internal.h | 27 --- arch/x86/include/asm/trace/fpu.h| 5 +- arch/x86/kernel/fpu/core.c |

[PATCH 25/27] x86/fpu: Add a fastpath to copy_fpstate_to_sigframe()

which can handle faults. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 34 ++ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index f20e1d1fffa29

[PATCH 21/27] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory

rror value and the caller handles it. copy_user_to_fpregs_zeroing() and its helpers remain and will be used later for a fastpath optimisation. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/internal.h | 43 arch/x86/kernel/fpu/signal.c

[PATCH 26/27] x86/fpu: Restore FPU register in copy_fpstate_to_sigframe() in order to use the fastpath

mpt to save them directly. The direct save may fail but should only happen on the first invocation or after fork() while the page is RO. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 25 + 1 file changed, 13 insertions(+), 12 deletions(-) diff --

[PATCH 11/27] x86/fpu: Make get_xsave_field_ptr() and get_xsave_addr() use feature number instead of mask

ature_mask consistently. This results in changes to the kvm code as: feature -> xfeature_mask index -> xfeature_nr Suggested-by: Dave Hansen Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/xstate.h | 4 ++-- arch/x86/kernel/fpu/xstate.c | 22 ++--

[PATCH 24/27] x86/fpu: Add a fastpath to __fpu__restore_sig()

the slowpath which can handle pagefaults. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 16 ++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index a5b086ec426a5..f20e1d1fffa29 100644

[PATCH 27/27] x86/pkeys: add PKRU value to init_fpstate

`init_fpstate' and initialize the PKRU value to 0. Add the `init_pkru_value' to `init_fpstate' so it is set to the init value in such a case. In theory we could drop copy_init_pkru_to_fpregs() because restoring the PKRU at return-to-userland should be enough. Signed-off-by: Sebastian Andrzej Siewior

[PATCH 15/27] x86/fpu: Eager switch PKRU state

it the kernel thread would end up with a random value which it inherited from the previous user task. Signed-off-by: Rik van Riel [bigeasy: save pkru to xstate, no cache, don't use __raw_xsave_addr()] Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm

[PATCH 09/27] x86/fpu: Add (__)make_fpregs_active helpers

From: Rik van Riel Add helper function that ensures the floating point registers for the current task are active. Use with preemption disabled. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/api.h | 11 +++ arch/x86/include/asm

Re: [PATCH 18/24] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD

On 2019-03-31 20:20:25 [+0200], Thomas Gleixner wrote: > > I think this should do the following: > > fpregs_lock(); > if (!test_thread_flag(TIF_NEED_FPU_LOAD)) { > pagefault_disable(); > ret = copy_fpu_to_user(...); > pagefault_enable(); >

[ANNOUNCE] v5.0.5-rt3

Dear RT folks! I'm pleased to announce the v5.0.5-rt3 patch set. Changes since v5.0.5-rt2: - Multiple fixes for build failures introduced by the printk series. Reported by the kbuild test robot, patched by John Ogness. - Various powerpc fixes: - Reorder TIF bits so the assembly

Re: [RT WARNING] DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current) with fsfreeze (4.19.25-rt16)

On 2019-03-26 10:34:21 [+0100], Juri Lelli wrote: > Hi, Hi, … > # for I in `seq 10`; do fsfreeze -f ./testmount; sleep 1; fsfreeze -u > ./testmount; done > > [ cut here ] > DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current) > WARNING: CPU: 10 PID: 1226 at

[PATCH 2/4] powerpc/stackprotector: work around stack-guard init from atomic

This is invoked from the secondary CPU in atomic context. On x86 we use tsc instead. On Power we XOR it against mftb() so lets use stack address as the initial value. Signed-off-by: Sebastian Andrzej Siewior --- arch/powerpc/include/asm/stackprotector.h | 4 1 file changed, 4 insertions

[PATCH 1/4] printk: An all-in-one commit to fix build failures

From: John Ogness This commit contains addresses several build failures which were reported by the kbuild test robot. The fixes were folded into the original commits. Reported-by: kbuild test robot Signed-off-by: John Ogness Signed-off-by: Sebastian Andrzej Siewior --- arch/powerpc/kernel

[PATCH 4/4] powerpc: reshuffle TIF bits

immediates. Signed-off-by: Sebastian Andrzej Siewior --- arch/powerpc/include/asm/thread_info.h | 13 - arch/powerpc/kernel/entry_32.S | 12 +++- arch/powerpc/kernel/entry_64.S | 12 +++- 3 files changed, 22 insertions(+), 15 deletions(-) diff --git

[PATCH 3/4] powerpc/pseries/iommu: Use a locallock instead local_irq_save()

The locallock protects the per-CPU variable tce_page. The function attempts to allocate memory while tce_page is protected (by disabling interrupts). Use local_irq_save() instead of local_irq_disable(). Signed-off-by: Sebastian Andrzej Siewior --- arch/powerpc/platforms/pseries/iommu.c | 16

Re: [PATCH 1/2] workqueue: Use normal rcu

On 2019-03-22 10:43:34 [-0700], Tejun Heo wrote: > Hello, Hi, > We can switch but it doesn't really say why we'd want to. Can you > please explain why this is better? there is this undocumented part. Avoiding the sched RCU means also we are more preemptible which is good :) Especially on -RT

Re: [PATCH 21/24] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory

On 2019-03-21 21:26:29 [+0100], To linux-kernel@vger.kernel.org wrote: > diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c > index 5a467a381245c..052a16c96218f 100644 > --- a/arch/x86/kernel/fpu/signal.c > +++ b/arch/x86/kernel/fpu/signal.c > @@ -297,28 +298,63 @@ static int

Re: [PATCH RT 4.19] rcutorture: Fix oops when selecting non-default torture_type

On 2019-03-21 22:21:21 [-0500], Scott Wood wrote: > rcu_bh is disabled on PREEMPT_RT via a stub ops that has no name. Thus, > if a torture_type other than "rcu" is used, rcu_torture_init() will > pass NULL to strcmp() when iterating over torture_ops[], and oops. > > Signed-off-by: Scott Wood >

Re: [PATCH 1/2] workqueue: Use normal rcu

Thomas Gleixner > [bigeasy: mangle changelog a little] > Signed-off-by: Sebastian Andrzej Siewior A gentle ping. Sebastian

[PATCH 08/24] x86/fpu: Remove user_fpu_begin()

_begin() block could set fpu_fpregs_owner_ctx to NULL but a kernel thread does not use user_fpu_begin(). This is a leftover from the lazy-FPU time. Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's content. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- ar

[PATCH 12/24] x86/pkru: Provide .*_pkru_ins() functions

() suffix. __write_pkru() will just invoke __write_pkru_isn() but in a flowup patch will also read back the value. Suggested-by: Dave Hansen Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/pgtable.h | 2 +- arch/x86/include/asm/special_insns.h | 12 +--- arch/x86/kvm

[PATCH 04/24] x86/fpu: Always init the `state' in fpu__clear()

ime an opcode is emulated. It makes the removal of ->initialized easier if the struct is also initialized in the FPU-less case at the same time. Move fpu__initialize() before the FPU check so it is also performed in the FPU-less case. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav

[PATCH 09/24] x86/fpu: Add (__)make_fpregs_active helpers

From: Rik van Riel Add helper function that ensures the floating point registers for the current task are active. Use with preemption disabled. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/api.h | 11 +++ arch/x86/include/asm

[PATCH 14/24] x86/pkeys: Don't check if PKRU is zero before writting it

Andrzej Siewior --- arch/x86/mm/pkeys.c | 7 --- 1 file changed, 7 deletions(-) diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index 05bb9a44eb1c3..50f65fc1b9a3f 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -142,13 +142,6 @@ u32 init_pkru_value = PKRU_AD_KEY( 1

[PATCH 16/24] x86/entry: Add TIF_NEED_FPU_LOAD

-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/internal.h | 6 ++ arch/x86/include/asm/thread_info.h | 2 ++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 82ff84a4c4ab7..b12874b7cf0cf 100644 --- a/arch/x86

[PATCH 13/24] x86/fpu: Only write PKRU if it is different from current

Dave Hansen says that the `wrpkru' is more expensive than `rdpkru'. It has a higher cycle cost and it's also practically a (light) speculation barrier. As an optimisation read the current PKRU value and only write the new one if it is different. Signed-off-by: Sebastian Andrzej Siewior

[PATCH 19/24] x86/fpu: Update xstate's PKRU value on write_pkru()

During the context switch the xstate is loaded which also includes the PKRU value. If xstate is restored on return to userland it is required that the PKRU value in xstate is the same as the one in the CPU. Save the PKRU in xstate during modification. Signed-off-by: Sebastian Andrzej Siewior

[PATCH 02/24] x86/fpu: Remove fpu__restore()

There are no users of fpu__restore() so it is time to remove it. The comment regarding fpu__restore() and TS bit is stale since commit b3b0870ef3ffe ("i387: do not preload FPU state at task switch time") and has no meaning since. Signed-off-by: Sebastian Andrzej Siewior --- Doc

[PATCH 11/24] x86/fpu: Make get_xsave_field_ptr() and get_xsave_addr() use feature number instead of mask

ature_mask consistently. This results in changes to the kvm code as: feature -> xfeature_mask index -> xfeature_nr Suggested-by: Dave Hansen Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/xstate.h | 4 ++-- arch/x86/kernel/fpu/xstate.c | 22 ++--

[PATCH 05/24] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()

pdate the comment to reflect that the "state is always live". Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 35 --- 1 file changed, 8 insertions(+), 27 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/k

[PATCH 10/24] x86/fpu: Make __raw_xsave_addr() use feature number instead of mask

Most users of __raw_xsave_addr() use a feature number, shift it to a mask and then __raw_xsave_addr() shifts it back to the feature number. Make __raw_xsave_addr() use the feature number as an argument. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- arch/x86/kernel

[PATCH 20/24] x86/fpu: Inline copy_user_to_fpregs_zeroing()

Start refactoring __fpu__restore_sig() by inlining copy_user_to_fpregs_zeroing(). Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 42 1 file changed, 19 insertions(+), 23 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b

[PATCH 21/24] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory

rror value and the caller handles it. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/internal.h | 33 ++- arch/x86/kernel/fpu/signal.c| 62 +++-- 2 files changed, 72 insertions(+), 23 deletions(-) diff --git a/arch/x86/include/asm/fpu/int

[PATCH 22/24] x86/fpu: Merge the two code paths in __fpu__restore_sig()

s and keep the !ia32_fxstate version. Copy only the user_i387_ia32_struct data structure in the ia32_fxstate. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 146 ++- 1 file changed, 57 insertions(+), 89 deletions(-) diff --git a/arch/x86/

[PATCH 03/24] x86/fpu: Remove preempt_disable() in fpu__clear()

_fpu_begin() could also force to save FPU's registers after fpu__initialize() without changing the outcome here. Remove the preempt_disable() section in fpu__clear(), preemption here does not hurt. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Borislav Petkov --- arch/x86/kernel/fpu/core.c

[PATCH 17/24] x86/fpu: Always store the registers in copy_fpstate_to_sigframe()

an earlier version of the patchset while there still was lazy-FPU on x86. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/internal.h | 43 - arch/x86/kernel/fpu/signal.c| 34 +-- 2 files changed

[PATCH 01/24] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig()

ered okay, load it. Should something go wrong, return with an error and without altering the original FPU registers. The removal of "fpu__initialize()" is a nop because fpu->initialized is already set for the user task. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Borislav Petkov -

[PATCH 23/24] x86/fpu: Defer FPU state load until return to userspace

gned-off-by: Sebastian Andrzej Siewior --- arch/x86/entry/common.c | 8 +++ arch/x86/include/asm/fpu/api.h | 22 +- arch/x86/include/asm/fpu/internal.h | 27 --- arch/x86/include/asm/trace/fpu.h| 5 +- arch/x86/kernel/fpu/core.c |

[PATCH 06/24] x86/fpu: Don't save fxregs for ia32 frames in copy_fpstate_to_sigframe()

fpu__clear(). Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 4 1 file changed, 4 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index de83d0ed9e14e..2f044021fde2b 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/ker

[PATCH 18/24] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD

From: Rik van Riel The FPU registers need only to be saved if TIF_NEED_FPU_LOAD is not set. Otherwise this has been already done and can be skipped. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/kernel/fpu/signal.c | 11 ++- 1 file changed, 10

[PATCH 07/24] x86/fpu: Remove fpu->initialized

lid before switch_fpu_finish() is invoked so ->mm is seen of the new task instead the old one. Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/ia32/ia32_signal.c | 17 +++ arch/x86/include/asm/fpu/internal.h | 18 arch/x86/include/asm/fpu/types.h| 9 arch/x86/incl

[PATCH 15/24] x86/fpu: Eager switch PKRU state

it the kernel thread would end up with a random value which it inherited from the previous user task. Signed-off-by: Rik van Riel [bigeasy: save pkru to xstate, no cache, don't use __raw_xsave_addr()] Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm

[PATCH 24/24] x86/pkeys: add PKRU value to init_fpstate

`init_fpstate' and initialize the PKRU value to 0. Add the `init_pkru_value' to `init_fpstate' so it is set to the init value in such a case. In theory we could drop copy_init_pkru_to_fpregs() because restoring the PKRU at return-to-userland should be enough. Signed-off-by: Sebastian Andrzej Siewior

[PATCH v8] x86: load FPU registers on return to userland

x86/fpu: Always store the registers in copy_fpstate_to_sigframe() x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD x86/fpu: Defer FPU state load until return to userspace Sebastian Andrzej Siewior (19): x86/fpu: Remove fpu->initialized usage in __fpu__restore_s

Re: [PATCH 14/22] x86/fpu: Eager switch PKRU state

On 2019-03-12 17:06:18 [-0700], Dave Hansen wrote: > Thanks for doing this. I'll see if I can dig into the test case and > figure out why it's not doing what I expected. It might be that the CPU > _could_ go back to the init state but chooses not to, or that something > else is taking us out of

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-20 16:46:01 [-0700], Paul E. McKenney wrote: > Thank you! I reverted v2 and applied this one with the same sort of > update. Testing is going well thus far aside from my failing to add > the required "=0" after the rcutree.use_softirq. I will probably not > be the only one who will

[PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

. Reported-by: Thomas Gleixner Tested-by: Mike Galbraith Signed-off-by: Sebastian Andrzej Siewior --- v2…v3: - Ensure that with RCU_BOOST=y the callback is invoked in thread context. Pointed out by Joel Fernandes. - Swap the init logic so it initializes the rcuc thread

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-20 11:12:10 [-0700], Paul E. McKenney wrote: > We could name it something like "use_softirq" and initialize it to true. > I am OK either way. I had to add one hunk to get it compiled. It worked then. Let me swap the logic as you suggested and then I repost the whole thing. This will

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-20 10:30:01 [-0700], Paul E. McKenney wrote: > On Wed, Mar 20, 2019 at 05:35:32PM +0100, Sebastian Andrzej Siewior wrote: > > On 2019-03-20 09:15:00 [-0700], Paul E. McKenney wrote: > > > I am considering making it a module_param() to avoid namespace pollution, > &

[ANNOUNCE] v5.0.3-rt1

Dear RT folks! I'm pleased to announce the v5.0.3-rt1 patch set. Changes since v4.19.25-rt16: - rebase to v5.0 - Several ARM architectures have a so called "boot_lock" in their SMP bring up code. In previous releases the boot_lock was converted to to a raw_spinlock in order to get

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-20 09:15:00 [-0700], Paul E. McKenney wrote: > I am considering making it a module_param() to avoid namespace pollution, > as it would become something like rcutree.nosoftirq. > > Thoughts? nope, perfect. > Thanx, Paul Sebastian

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-20 08:44:40 [-0700], Paul E. McKenney wrote: > > And it does seem to work better. I will give it more intense testing > later on, but in the meantime I have merged this change into your > earlier patch. thanks. > We will see whether or not I am able summon up the courage to push it

Re: [RFC PATCH RT] x86/tsc: Add option to disable tsc clocksource watchdog

On 2019-03-14 08:09:51 [+0100], Juri Lelli wrote: > Hi, > > On 07/03/19 13:09, Juri Lelli wrote: > > Clocksource watchdog has been found responsible for generating latency > > spikes (in the 10-20 us range) when woken up to check for TSC stability. > > > > Add an option to disable it at boot. >

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-19 12:44:19 [+0100], To Paul E. McKenney wrote: > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 0f31b79eb6761..0a719f726e149 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c … > +/* > + * Spawn per-CPU RCU core processing kthreads. > + */ > +static int __init

Re: [PATCH] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-19 20:26:13 [-0400], Joel Fernandes wrote: > > @@ -2769,19 +2782,121 @@ static void invoke_rcu_callbacks(struct rcu_data > > *rdp) > > { > > if (unlikely(!READ_ONCE(rcu_scheduler_fully_active))) > > return; > > - if (likely(!rcu_state.boost)) { > > -

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-19 09:50:07 [-0700], Paul E. McKenney wrote: > Besides, it looks very weird for me to have two Signed-off-by lines. ;-) See commit 602cae04c4864 ("perf/x86/intel: Delay memory deallocation until x86_pmu_dead_cpu()") > In theory, the trace_rcu_utilization() should be added, just like

Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

On 2019-03-19 08:59:23 [-0700], Paul E. McKenney wrote: > I doubt that there is any code left from my original, so I set you as > author. I always forward ported it the patch over the years. So if it is no longer what it was once so be it. > I queued this and am starting tests without setting

[PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

at the RCU-boosting priority. Reported-by: Thomas Gleixner Tested-by: Mike Galbraith Signed-off-by: Paul E. McKenney [bigeasy: add rcunosoftirq option] Signed-off-by: Sebastian Andrzej Siewior --- v1…v2: - rebased to Paul's rcu/dev tree/branch - Replaced Mike's email with @gm

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