On Mon, Mar 25, 2024 at 08:40:08AM +0200, Adrian Hunter wrote:
> Put together declaration and initialization of local variables.
>
> Suggested-by: Thomas Gleixner
> Signed-off-by: Adrian Hunter
> ---
Nothing wrong with this patch, but it is highly unlikely this code is
actually tested much.
On Mon, Apr 15, 2024 at 08:00:26PM +0300, Mike Rapoport wrote:
> On Mon, Apr 15, 2024 at 12:47:50PM +0200, Peter Zijlstra wrote:
> > On Thu, Apr 11, 2024 at 07:05:25PM +0300, Mike Rapoport wrote:
> >
> > > To populate the cache, a writable large page i
On Thu, Apr 11, 2024 at 07:05:25PM +0300, Mike Rapoport wrote:
> To populate the cache, a writable large page is allocated from vmalloc with
> VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then remapped as
> ROX.
> +static void execmem_invalidate(void *ptr, size_t size, bool writable)
On Thu, Apr 11, 2024 at 07:05:24PM +0300, Mike Rapoport wrote:
> diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
> index 45a280f2161c..b4d6868df573 100644
> --- a/arch/x86/kernel/alternative.c
> +++ b/arch/x86/kernel/alternative.c
> @@ -504,17 +513,17 @@ void
On Thu, Apr 11, 2024 at 07:00:43PM +0300, Mike Rapoport wrote:
> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .flags = EXECMEM_KASAN_SHADOW,
> + .alignment = MODULE_ALIGN,
> +
On Thu, Apr 11, 2024 at 07:00:42PM +0300, Mike Rapoport wrote:
> +static struct execmem_info execmem_info __ro_after_init = {
> + .ranges = {
> + [EXECMEM_DEFAULT] = {
> + .start = MODULES_VADDR,
> + .end = MODULES_END,
> +
On Thu, Apr 11, 2024 at 07:00:41PM +0300, Mike Rapoport wrote:
> +/**
> + * enum execmem_type - types of executable memory ranges
> + *
> + * There are several subsystems that allocate executable memory.
> + * Architectures define different restrictions on placement,
> + * permissions, alignment
On Wed, Oct 18, 2023 at 10:07:45PM +0530, Srikar Dronamraju wrote:
> There are some variables that are only updated at boot time.
> So add read_mostly attribute to such variables
You don't have __ro_after_init ?
On Thu, Oct 19, 2023 at 03:48:48PM +1100, Michael Ellerman wrote:
> Srikar Dronamraju writes:
> > Like L2-cache info, coregroup information which is used to determine MC
> > sched domains is only present on dedicated LPARs. i.e PowerVM doesn't
> > export coregroup information for shared processor
On Thu, Oct 19, 2023 at 03:38:40PM +1100, Michael Ellerman wrote:
> Srikar Dronamraju writes:
> > If there are shared processor LPARs, underlying Hypervisor can have more
> > virtual cores to handle than actual physical cores.
> >
> > Starting with Power 9, a core has 2 nearly independent thread
On Wed, Aug 30, 2023 at 05:56:14PM +0530, Srikar Dronamraju wrote:
> Currently there are four powerpc specific sched topologies. These are
> all statically defined. However not all these topologies are used by
> all powerpc systems.
>
> To avoid unnecessary degenerations by the scheduler ,
On Mon, Jul 17, 2023 at 03:51:25PM +0200, Vincent Guittot wrote:
> On Wed, 12 Jul 2023 at 16:11, Peter Zijlstra wrote:
> >
> > Hi
> >
> > Thomas just tripped over the x86 topology setup creating a 'DIE' domain
> > for the package mask :-)
>
> May be a link
On Wed, Jul 12, 2023 at 04:02:38PM +0100, Valentin Schneider wrote:
> On 12/07/23 16:10, Peter Zijlstra wrote:
> > Hi
> >
> > Thomas just tripped over the x86 topology setup creating a 'DIE' domain
> > for the package mask :-)
> >
> > Since these names a
On Tue, Jul 11, 2023 at 06:08:26PM +0200, Christophe Leroy wrote:
> This series adds UACCESS validation for PPC32. It includes
> a dozen of changes to objtool core.
>
> It applies on top of series "Cleanup/Optimise KUAP (v3)"
>
Hi
Thomas just tripped over the x86 topology setup creating a 'DIE' domain
for the package mask :-)
Since these names are SCHED_DEBUG only, rename them.
I don't think anybody *should* be relying on this, but who knows.
Signed-off-by: Peter Zijlstra (Intel)
---
arch/powerpc/kernel/smp.c | 2
On Mon, May 15, 2023 at 01:46:01PM +0200, Tobias Huschle wrote:
> The current load balancer implementation implies that scheduler groups,
> within the same domain, all host the same number of CPUs. This is
> reflected in the condition, that a scheduler group, which is load
> balancing and
On Thu, Jun 22, 2023 at 09:47:22AM -0300, Marcelo Tosatti wrote:
> > there's patches that cure the thp abuse of this.
>
> The other case where the IPI can happen is:
>
> CPU-0 CPU-1
>
> tlb_remove_table
> tlb_remove_table_sync_one
> IPI
>
On Tue, Jun 20, 2023 at 05:46:18PM +0300, Yair Podemsky wrote:
> @@ -191,7 +191,13 @@ static void tlb_remove_table_smp_sync(void *arg)
> /* Simply deliver the interrupt */
> }
>
> -void tlb_remove_table_sync_one(void)
> +#ifdef CONFIG_ARCH_HAS_CPUMASK_BITS
> +#define REMOVE_TABLE_IPI_MASK
On Sat, Jun 24, 2023 at 10:06:23AM +, Christophe Leroy wrote:
> Hello Josh and Peter,
>
> As mentionned in the cover letter of my series "powerpc/objtool: uaccess
> validation for PPC32 (v3)" [1], a few switch table lookup fail, and it
> would help if you had ideas on how to handle them.
>
On Thu, Jun 22, 2023 at 12:54:36PM +0200, Christophe Leroy wrote:
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index f850ab892ad5..8ac5711a055f 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -218,6 +218,7 @@ static bool __dead_end_function(struct
On Thu, Jun 22, 2023 at 12:54:34PM +0200, Christophe Leroy wrote:
> On x86, UACCESS is controlled by two instructions: STAC and CLAC.
> STAC instruction enables UACCESS while CLAC disables UACCESS.
> This is simple enough for objtool to locate UACCESS enable and
> disable.
>
> But on powerpc it
On Thu, Jun 22, 2023 at 12:54:33PM +0200, Christophe Leroy wrote:
> In code there is often a pattern like:
>
> load jump table address
> do some test
> conditional jump to label1:
> do something
> unconditional jump to label2:
> label1:
> do something else
>
On Thu, Jun 22, 2023 at 12:54:32PM +0200, Christophe Leroy wrote:
> On powerpc, switch tables are relative, than means the address of the
> table is added to the value of the entry in order to get the pointed
> address: (r10 is the table address, r4 the index in the table)
>
> lis r10,0
rn is dead.
>
> To overcome this situation, introduce INSN_RETURN_CONDITIONAL which
> is taken as a confirmation that a function is not noreturn but still
> sees following code as reachable.
>
> Signed-off-by: Christophe Leroy
Acked-by: Peter Zijlstra (Intel)
> ---
> tools/objto
ing a 32 bits or 64 bits kernel.
>
> Therefore JUMP_ENTRY_SIZE must depend on elf_class_addrsize(elf).
>
> To allow that, entries[] table must be initialised at runtime. This is
> easily done by moving it into its only user which is special_get_alts().
>
> Signed-off-by: Chris
text_tracking in the kernel space, this was removed due to race
> condition concerns.
> - for archs that do not maintain mm_cpumask the mask used should be
> cpu_online_mask (Peter Zijlstra).
>
Would it not be much better to fix the root cause? As per the last time,
there's patches that cure the thp abuse of this.
On Tue, Jun 20, 2023 at 10:51:25AM +0530, Naveen N Rao wrote:
> Christophe Leroy wrote:
> > This reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.
> >
> > That commit aimed at optimising the code around generation of
> > WARN_ON/BUG_ON but this leads to a lot of dead code erroneously
> >
Few comments..
On Fri, Jun 16, 2023 at 03:47:52PM +0200, Christophe Leroy wrote:
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 0fcf99c91400..f945fe271706 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -236,6 +236,7 @@ static bool
On Thu, Jun 01, 2023 at 01:12:56PM +0300, Mike Rapoport wrote:
> +static void __init_or_module do_text_poke(void *addr, const void *opcode,
> size_t len)
> +{
> + if (system_state < SYSTEM_RUNNING) {
> + text_poke_early(addr, opcode, len);
> + } else {
> +
On Wed, May 24, 2023 at 03:44:59PM +1000, Stephen Rothwell wrote:
> Hi all,
>
> After merging the tip tree, today's linux-next build (powerpc
> pseries_le_defconfig) failed to boot like this:
>
> Built 1 zonelists, mobility grouping on. Total pages: 32736
> Policy zone: Normal
> mem
On Thu, May 11, 2023 at 03:02:55PM +0100, Matthew Wilcox wrote:
> We also talked about moving x86 to always RCU-free page tables in
> order to make accessing /proc/$pid/smaps lockless. I believe Michel
> is going to take a swing at this project.
Shouldn't be too controversial I think --
On Wed, May 10, 2023 at 08:16:34PM -0700, Hugh Dickins wrote:
> Thanks for looking so quickly, Peter: I didn't Cc you on this particular
> series, but shall certainly be doing so on the ones that follow, because
> a few of those patches go into interesting pmdp_get_lockless() territory.
I'm in
On Tue, May 09, 2023 at 10:08:37PM -0700, Hugh Dickins wrote:
> In rare transient cases, not yet made possible, pte_offset_map() and
> pte_offset_map_lock() may not find a page table: handle appropriately.
>
> Signed-off-by: Hugh Dickins
> ---
> arch/x86/kernel/ldt.c | 6 --
> 1 file
On Wed, Apr 26, 2023 at 09:44:22AM -0400, Joel Fernandes wrote:
> How could you control which code paths don't have the stack protector?
> Just curious.
https://lkml.kernel.org/r/20230412-no_stackp-v2-0-116f9fe4b...@google.com
On Tue, Apr 25, 2023 at 06:59:29AM -0400, Joel Fernandes wrote:
> > I'm a little confused; the way I understand the whole stack protector
> > thing to work is that we push a canary on the stack at call and on
> > return check it is still valid. Since in general tasks randomly migrate,
> > the
a new CPU.
>
> Did I get that right?
>
> IMO, even without a reproducer, gcc on PPC should just not do that,
> that feels terribly broken for the kernel. I wonder what clang does,
> I'll go poke around with compilerexplorer after lunch.
>
> Adding +Peter Zijlstra
Other than that,
Acked-by: Peter Zijlstra (Intel)
On Wed, Apr 12, 2023 at 03:37:50PM +0200, Uros Bizjak wrote:
> On Wed, Apr 12, 2023 at 1:33 PM Peter Zijlstra wrote:
> >
> > On Wed, Apr 05, 2023 at 04:17:08PM +0200, Uros Bizjak wrote:
> > > diff --git a/arch/powerpc/include/asm/local.h
> > > b/arch/powerp
On Wed, Apr 05, 2023 at 04:17:08PM +0200, Uros Bizjak wrote:
> diff --git a/arch/powerpc/include/asm/local.h
> b/arch/powerpc/include/asm/local.h
> index bc4bd19b7fc2..45492fb5bf22 100644
> --- a/arch/powerpc/include/asm/local.h
> +++ b/arch/powerpc/include/asm/local.h
> @@ -90,6 +90,17 @@ static
On Thu, Apr 06, 2023 at 05:51:52PM +0200, David Hildenbrand wrote:
> On 06.04.23 17:02, Peter Zijlstra wrote:
> > DavidH, what do you thikn about reviving Jann's patches here:
> >
> >https://bugs.chromium.org/p/project-zero/issues/detail?id=2365#c1
> >
>
On Thu, Apr 06, 2023 at 04:42:02PM +0200, David Hildenbrand wrote:
> On 06.04.23 16:04, Peter Zijlstra wrote:
> > On Thu, Apr 06, 2023 at 03:29:28PM +0200, Peter Zijlstra wrote:
> > > On Thu, Apr 06, 2023 at 09:38:50AM -0300, Marcelo Tosatti wrote:
> > >
> > >
On Thu, Apr 06, 2023 at 04:04:23PM +0200, Peter Zijlstra wrote:
> On Thu, Apr 06, 2023 at 03:29:28PM +0200, Peter Zijlstra wrote:
> > On Thu, Apr 06, 2023 at 09:38:50AM -0300, Marcelo Tosatti wrote:
> >
> > > > To actually hit this path you're doing something really dod
On Thu, Apr 06, 2023 at 03:11:52PM +0100, Valentin Schneider wrote:
> On 06/04/23 15:38, Peter Zijlstra wrote:
> > On Wed, Apr 05, 2023 at 01:45:02PM +0100, Valentin Schneider wrote:
> >>
> >> I've been hacking on something like this (CSD deferral for NOHZ-full),
>
On Thu, Apr 06, 2023 at 03:29:28PM +0200, Peter Zijlstra wrote:
> On Thu, Apr 06, 2023 at 09:38:50AM -0300, Marcelo Tosatti wrote:
>
> > > To actually hit this path you're doing something really dodgy.
> >
> > Apparently khugepaged is using the same infr
On Wed, Apr 05, 2023 at 01:45:02PM +0100, Valentin Schneider wrote:
> On 05/04/23 14:05, Frederic Weisbecker wrote:
> > static void smp_call_function_many_cond(const struct cpumask *mask,
> > smp_call_func_t func, void *info,
> > @@ -946,10 +948,13 @@ static
On Thu, Apr 06, 2023 at 09:49:22AM -0300, Marcelo Tosatti wrote:
> > > 2) Depends on the application and the definition of "occasional".
> > >
> > > For certain types of applications (for example PLC software or
> > > RAN processing), upon occurrence of an event, it is necessary to
> > >
On Thu, Apr 06, 2023 at 09:38:50AM -0300, Marcelo Tosatti wrote:
> > To actually hit this path you're doing something really dodgy.
>
> Apparently khugepaged is using the same infrastructure:
>
> $ grep tlb_remove_table khugepaged.c
> tlb_remove_table_sync_one();
>
On Wed, Apr 05, 2023 at 04:43:14PM -0300, Marcelo Tosatti wrote:
> Two points:
>
> 1) For a virtualized system, the overhead is not only of executing the
> IPI but:
>
> VM-exit
> run VM-exit code in host
> handle IPI
> run VM-entry code in host
> VM-entry
I
On Wed, Apr 05, 2023 at 04:45:32PM -0300, Marcelo Tosatti wrote:
> On Wed, Apr 05, 2023 at 01:10:07PM +0200, Frederic Weisbecker wrote:
> > On Wed, Apr 05, 2023 at 12:44:04PM +0200, Frederic Weisbecker wrote:
> > > On Tue, Apr 04, 2023 at 04:42:24PM +0300, Yair Podemsky wrote:
> > > > + int
On Wed, Apr 05, 2023 at 01:10:07PM +0200, Frederic Weisbecker wrote:
> On Wed, Apr 05, 2023 at 12:44:04PM +0200, Frederic Weisbecker wrote:
> > On Tue, Apr 04, 2023 at 04:42:24PM +0300, Yair Podemsky wrote:
> > > + int state = atomic_read(>state);
> > > + /* will return true only for cpus in
On Tue, Apr 04, 2023 at 05:12:17PM +0200, Peter Zijlstra wrote:
> > case 2:
> > CPU-A CPU-B
> >
> > modify pagetables
> > tlb_flush (memory barrier)
> > state == CONT
On Tue, Apr 04, 2023 at 04:42:24PM +0300, Yair Podemsky wrote:
> The tlb_remove_table_smp_sync IPI is used to ensure the outdated tlb page
> is not currently being accessed and can be cleared.
> This occurs once all CPUs have left the lockless gup code section.
> If they reenter the page table
On Tue, Apr 04, 2023 at 04:42:23PM +0300, Yair Podemsky wrote:
> diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
> index 2b93cf6ac9ae..5ea9be6fb87c 100644
> --- a/mm/mmu_gather.c
> +++ b/mm/mmu_gather.c
> @@ -191,7 +191,13 @@ static void tlb_remove_table_smp_sync(void *arg)
> /* Simply
On Thu, Mar 23, 2023 at 04:25:25PM +, Valentin Schneider wrote:
> On 22/03/23 15:04, Peter Zijlstra wrote:
> > @@ -798,14 +794,20 @@ static void smp_call_function_many_cond(
> > }
> >
> > /*
> > +* Trace each smp_functio
On Wed, Mar 22, 2023 at 06:22:28PM +, Valentin Schneider wrote:
> On 22/03/23 18:22, Peter Zijlstra wrote:
> >>hackbench-157 [001]10.894320: ipi_send_cpu: cpu=3
> >> callsite=check_preempt_curr+0x37 callback=0x0
> >
> > Argua
On Wed, Mar 22, 2023 at 05:01:13PM +, Valentin Schneider wrote:
> > So I was thinking something like this:
> Hm, this does get rid of the func being passed down the helpers, but this
> means the trace events are now stateful, i.e. I need the first and last
> events in a CSD stack to figure
On Wed, Mar 22, 2023 at 12:20:28PM +, Valentin Schneider wrote:
> On 22/03/23 10:53, Peter Zijlstra wrote:
> > Hurmph... so we only really consume @func when we IPI. Would it not be
> > more useful to trace this thing for *every* csd enqeued?
>
> It's true that any CSD e
On Wed, Mar 22, 2023 at 10:39:55AM +0100, Peter Zijlstra wrote:
> On Tue, Mar 07, 2023 at 02:35:52PM +, Valentin Schneider wrote:
> > trace_ipi_raise() is unsuitable for generically tracing IPI sources due to
> > its "reason" argument being an uninformative str
On Tue, Mar 07, 2023 at 02:35:58PM +, Valentin Schneider wrote:
> @@ -477,6 +490,25 @@ static __always_inline void csd_unlock(struct
> __call_single_data *csd)
> smp_store_release(>node.u_flags, 0);
> }
>
> +static __always_inline void
> +raw_smp_call_single_queue(int cpu, struct
On Tue, Mar 07, 2023 at 02:35:52PM +, Valentin Schneider wrote:
> trace_ipi_raise() is unsuitable for generically tracing IPI sources due to
> its "reason" argument being an uninformative string (on arm64 all you get
> is "Function call interrupts" for SMP calls).
>
> Add a variant of it that
On Thu, Feb 23, 2023 at 10:24:19PM +0100, Andrzej Hajda wrote:
> On 22.02.2023 18:04, Peter Zijlstra wrote:
> > On Wed, Jan 18, 2023 at 04:35:22PM +0100, Andrzej Hajda wrote:
> >
> > > Andrzej Hajda (7):
> > >arch: rename all internal names __xchg to __arch
On Sun, Feb 26, 2023 at 02:12:38PM -0800, Andrew Morton wrote:
> On Fri, 3 Feb 2023 17:18:37 +1000 Nicholas Piggin wrote:
>
> > On a 16-socket 192-core POWER8 system, the context_switch1_threads
> > benchmark from will-it-scale (see earlier changelog), upstream can
> > achieve a rate of about 1
On Wed, Jan 18, 2023 at 04:35:22PM +0100, Andrzej Hajda wrote:
> Andrzej Hajda (7):
> arch: rename all internal names __xchg to __arch_xchg
> linux/include: add non-atomic version of xchg
> arch/*/uprobes: simplify arch_uretprobe_hijack_return_addr
> llist: simplify __llist_del_all
>
On Thu, Feb 02, 2023 at 01:46:32PM +0530, Sachin Sant wrote:
> Following warning is seen with 6.2.0-rc6-next-20230201 on a
> Power10 server.
>
> [ cut here ]
> RCU not on for: check_return_regs_valid+0xc/0x1e0
> WARNING: CPU: 9 PID: 0 at include/linux/trace_recursion.h:162
On Wed, Jan 25, 2023 at 12:38:46AM -0800, Suren Baghdasaryan wrote:
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 2d6d790d9bed..6c7c70bf50dd 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -491,7 +491,13 @@ struct vm_area_struct {
>
On Thu, Jan 12, 2023 at 08:43:30PM +0100, Peter Zijlstra wrote:
> The __cpuidle functions will become a noinstr class, as such they need
> explicit annotations.
>
> Signed-off-by: Peter Zijlstra (Intel)
> Reviewed-by: Rafael J. Wysocki
> Acked-by: Frederic Weisbecker
> Tes
On Mon, Jan 16, 2023 at 04:59:04PM +, Mark Rutland wrote:
> I'm sorry to have to bear some bad news on that front. :(
Moo, something had to give..
> IIUC what's happenign here is the PSCI cpuidle driver has entered idle and RCU
> is no longer watching when arm64's cpu_suspend() manipulates
On Tue, Jan 17, 2023 at 01:24:46PM +0900, Masami Hiramatsu wrote:
> Hi Peter,
>
> On Thu, 12 Jan 2023 20:43:49 +0100
> Peter Zijlstra wrote:
>
> > Robot reported that trace_hardirqs_{on,off}() tickle the forbidden
> > _rcuidle() tracepoint through local_irq_{en,dis
On Thu, Jan 12, 2023 at 06:13:16PM -0600, Linus Torvalds wrote:
> On Thu, Jan 12, 2023 at 5:36 PM Mateusz Guzik wrote:
> >
> > To my understanding on said architecture failed cmpxchg still grants you
> > exclusive access to the cacheline, making immediate retry preferable
> > when trying to
OMAP3 uses full SoC suspend modes as idle states, as such it needs the
whole power-domain and clock-domain code from the idle path.
All that code is not suitable to run with RCU disabled, as such push
RCU-idle deeper still.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Tony Lindgren
Acked
OMAP was the one and only user.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Ulf Hansson
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/arm/mach-omap2/powerdomain.c | 10 +-
drivers/base/power/runtime.c
Doing RCU-idle outside the driver, only to then temporarily enable it
again before going idle is daft.
Notably: this converts all dt_init_idle_driver() and
__CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
again.
Signed-off-by: Peter Zijlstra (Intel)
---
kernel/trace/trace_preemptirq.c | 21 +
1 file changed, 13 insertions(+), 8 deletions(-)
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -20,6 +20,15 @@
static DEFINE_PER_CPU(int, tracing_irq_cpu
()
leaves .noinstr.text section
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/x86/include/asm/fpu/xcr.h |4 ++--
arch/x86/include/asm/special_insns.h |2 +-
arch/x86/kernel/fpu
Typical boot time setup; no need to suffer an indirect call for that.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Frederic Weisbecker
Reviewed-by: Rafael J. Wysocki
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/x86/kernel/process.c | 50
Hi All!
The (hopefully) final respin of cpuidle vs rcu cleanup patches. Barring any
objections I'll be queueing these patches in tip/sched/core in the next few
days.
v2: https://lkml.kernel.org/r/20220919095939.761690...@infradead.org
These here patches clean up the mess that is cpuidle vs
Doing RCU-idle outside the driver, only to then teporarily enable it
again before going idle is daft.
Notably the cpu_pm_*() calls implicitly re-enable RCU for a bit.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Frederic Weisbecker
Reviewed-by: Tony Lindgren
Acked-by: Rafael J. Wysocki
The __cpuidle functions will become a noinstr class, as such they need
explicit annotations.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
drivers/cpuidle/poll_state.c |6 +-
1
Add a few words on noinstr / __cpuidle usage.
Signed-off-by: Peter Zijlstra (Intel)
---
drivers/cpuidle/cpuidle.c | 12
include/linux/compiler_types.h | 10 ++
2 files changed, 22 insertions(+)
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.
Add two helpers for the cpuidle case that mirror the entry code.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony
ARCH_WANTS_NO_INSTR (a superset of CONFIG_GENERIC_ENTRY) disallows any
and all tracing when RCU isn't enabled.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
include/linux/tracepoint.h
.noinstr.text section
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/x86/boot/compressed/vmlinux.lds.S |1 +
arch/x86/coco/tdx/tdcall.S |2 ++
arch/x86/coco/tdx/tdx.c
vmlinux.o: warning: objtool: intel_idle_ibrs+0x17: call to spec_ctrl_current()
leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_ibrs+0x27: call to wrmsrl.constprop.0()
leaves .noinstr.text section
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked
Now that arch_cpu_idle() is expected to return with IRQs disabled,
avoid the useless STI/CLI dance.
Per the specs this is supposed to work, but nobody has yet relied up
this behaviour so broken implementations are possible.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
vmlinux.o: warning: objtool: __ct_user_enter+0x72: call to
__kasan_check_write() leaves .noinstr.text section
vmlinux.o: warning: objtool: __ct_user_exit+0x47: call to __kasan_check_write()
leaves .noinstr.text section
Signed-off-by: Peter Zijlstra (Intel)
---
kernel/context_tracking.c | 12
a cpuidle driver; but adding one would be the
recourse to (re)gain the other idle states.
Suggested-by: Tony Lindgren
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/arm/mach-omap2/pm24xx.c
to memcpy() leaves
.noinstr.text section
Remove the weak aliases to ensure nobody hijacks these functions and
add them to the noinstr section.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch
The perf_lopwr_cb() is called from the idle routines; there is no RCU
there, we must not enter tracing.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
arch/x86/events/amd/brs.c
OMAP was the one and only user.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Ulf Hansson
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
drivers/clk/clk.c |8
1 file changed, 4 insertions(+), 4 deletions
sitive RCU splats due to
incorrect hardirqs state")
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
drivers/idle/intel_idle.c |8 +---
1 file changed, 1 insertion(+), 7 deletions(-
No callers left that have already disabled RCU.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Mark Rutland
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
kernel/time/tick-broadcast-hrtimer.c | 29
From: Tony Lindgren
OMAP4 uses full SoC suspend modes as idle states, as such it needs the
whole power-domain and clock-domain code from the idle path.
All that code is not suitable to run with RCU disabled, as such push
RCU-idle deeper still.
Signed-off-by: Tony Lindgren
Signed-off-by: Peter
For all cpuidle drivers that use CPUIDLE_FLAG_RCU_IDLE, ensure that
all functions that call ct_cpuidle_enter() are marked __cpuidle.
( due to lack of noinstr validation on these platforms it is entirely
possible this isn't complete )
Signed-off-by: Peter Zijlstra (Intel)
---
arch/arm/mach
Per commit 56e62a737028 ("s390: convert to generic entry") the last
and only callers of trace_hardirqs_{on,off}_caller() went away, clean
up.
Cc: Sven Schnelle
Signed-off-by: Peter Zijlstra (Intel)
---
kernel/trace/trace_preemptirq.c | 29 -
1 file c
/restore and whitelist the thing.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
lib/ubsan.c |5 -
tools/objtool/check.c |1 +
2 files changed, 5 insertions(+), 1 deletion
Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is daft.
Notably both cpu_pm_enter() and cpu_cluster_pm_enter() implicity
re-enable RCU.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Frederic Weisbecker
Acked-by: Rafael J
The problem, per commit fc98c3c8c9dc ("printk: use rcuidle console
tracepoint"), was printk usage from the cpuidle path where RCU was
already disabled.
Per the patches earlier in this series, this is no longer the case.
Signed-off-by: Peter Zijlstra (Intel)
Reviewed-by: Sergey S
Tracing (kprobes included) and other compiler instrumentation relies
on a normal kernel runtime. Therefore all functions that disable RCU
should be noinstr, as should all functions that are called while RCU
is disabled.
Signed-off-by: Peter Zijlstra (Intel)
---
drivers/cpuidle/cpuidle.c | 37
For testing purposes.
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rafael J. Wysocki
Acked-by: Frederic Weisbecker
Tested-by: Tony Lindgren
Tested-by: Ulf Hansson
---
drivers/idle/intel_idle.c |7 ++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/idle/intel_idle.c
For all cpuidle drivers that do not use CPUIDLE_FLAG_RCU_IDLE (iow,
the simple ones) make sure all the functions are marked __cpuidle.
( due to lack of noinstr validation on these platforms it is entirely
possible this isn't complete )
Signed-off-by: Peter Zijlstra (Intel)
---
arch/arm
1 - 100 of 1076 matches
Mail list logo
