Displaying 20 results from an estimated 253 matches for "local_irq_sav".
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local_irq_save
2012 Dec 06
1
Question on local_irq_save/local_irq_retore
Hi, I have some confusion on local_irq_save() and local_irq_restore(). From
the definitions, you can see that local_irq_save() calls local_irq_disable().
But why there is no local_irq_enable() in local_irq_restore?
#define local_irq_save(x)
({
local_save_flags(x);
local_irq_disable();
})
#define local_irq_restore(x)
({
BUILD_B...
2020 Aug 11
3
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...he more
> problems I keep finding... bah bah bah.
That is, most of these irq-tracking problem are new because commit:
859d069ee1dd ("lockdep: Prepare for NMI IRQ state tracking")
changed irq-tracking to ignore the lockdep recursion count.
This then allows:
lock_acquire()
raw_local_irq_save();
current->lockdep_recursion++;
trace_lock_acquire()
... tracing ...
#PF under raw_local_irq_*()
__lock_acquire()
arch_spin_lock(&graph_lock)
pv-spinlock-wait()
local_irq_save() under raw_local_irq_*()
However afaict that just made a bad situation...
2020 Aug 11
3
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...he more
> problems I keep finding... bah bah bah.
That is, most of these irq-tracking problem are new because commit:
859d069ee1dd ("lockdep: Prepare for NMI IRQ state tracking")
changed irq-tracking to ignore the lockdep recursion count.
This then allows:
lock_acquire()
raw_local_irq_save();
current->lockdep_recursion++;
trace_lock_acquire()
... tracing ...
#PF under raw_local_irq_*()
__lock_acquire()
arch_spin_lock(&graph_lock)
pv-spinlock-wait()
local_irq_save() under raw_local_irq_*()
However afaict that just made a bad situation...
2007 Nov 26
0
[PATCH] [Mini-OS] Make gnttab allocation/free safe
...h>
#define NR_RESERVED_ENTRIES 8
@@ -31,20 +32,29 @@
static grant_entry_t *gnttab_table;
static grant_ref_t gnttab_list[NR_GRANT_ENTRIES];
+static __DECLARE_SEMAPHORE_GENERIC(gnttab_sem, NR_GRANT_ENTRIES);
static void
put_free_entry(grant_ref_t ref)
{
+ unsigned long flags;
+ local_irq_save(flags);
gnttab_list[ref] = gnttab_list[0];
gnttab_list[0] = ref;
-
+ local_irq_restore(flags);
+ up(&gnttab_sem);
}
static grant_ref_t
get_free_entry(void)
{
- unsigned int ref = gnttab_list[0];
+ unsigned int ref;
+ unsigned long flags;
+ down(&gnttab_se...
2020 Aug 05
9
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
On Wed, Aug 05, 2020 at 03:59:40PM +0200, Marco Elver wrote:
> On Wed, Aug 05, 2020 at 03:42PM +0200, peterz at infradead.org wrote:
> > Shouldn't we __always_inline those? They're going to be really small.
>
> I can send a v2, and you can choose. For reference, though:
>
> ffffffff86271ee0 <arch_local_save_flags>:
> ffffffff86271ee0: 0f 1f 44 00 00
2020 Aug 05
9
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
On Wed, Aug 05, 2020 at 03:59:40PM +0200, Marco Elver wrote:
> On Wed, Aug 05, 2020 at 03:42PM +0200, peterz at infradead.org wrote:
> > Shouldn't we __always_inline those? They're going to be really small.
>
> I can send a v2, and you can choose. For reference, though:
>
> ffffffff86271ee0 <arch_local_save_flags>:
> ffffffff86271ee0: 0f 1f 44 00 00
2020 Aug 06
0
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
On Thu, Aug 06, 2020 at 09:47:23AM +0200, Marco Elver wrote:
> Testing my hypothesis that raw then nested non-raw
> local_irq_save/restore() breaks IRQ state tracking -- see the reproducer
> below. This is at least 1 case I can think of that we're bound to hit.
Aaargh!
> diff --git a/init/main.c b/init/main.c
> index 15bd0efff3df..0873319dcff4 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -1041,6...
2020 Aug 12
0
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...200, peterz at infradead.org wrote:
> >
> > > So let me once again see if I can't find a better solution for this all.
> > > Clearly it needs one :/
> >
> > So the below boots without triggering the debug code from Marco -- it
> > should allow nesting local_irq_save/restore under raw_local_irq_*().
> >
> > I tried unconditional counting, but there's some _reallly_ wonky /
> > asymmetric code that wrecks that and I've not been able to come up with
> > anything useful.
> >
> > This one starts counting when local_irq...
2013 Aug 20
5
[PATCH-v3 1/4] idr: Percpu ida
...39;t passed
> + * __GFP_WAIT, of course).
> + *
> + * Will not fail if passed __GFP_WAIT.
> + */
> +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
> +{
> + DEFINE_WAIT(wait);
> + struct percpu_ida_cpu *tags;
> + unsigned long flags;
> + int tag;
> +
> + local_irq_save(flags);
> + tags = this_cpu_ptr(pool->tag_cpu);
> +
> + /* Fastpath */
> + tag = alloc_local_tag(pool, tags);
> + if (likely(tag >= 0)) {
> + local_irq_restore(flags);
> + return tag;
> + }
> +
> + while (1) {
> + spin_lock(&pool->lock);
> +
>...
2013 Aug 20
5
[PATCH-v3 1/4] idr: Percpu ida
...39;t passed
> + * __GFP_WAIT, of course).
> + *
> + * Will not fail if passed __GFP_WAIT.
> + */
> +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
> +{
> + DEFINE_WAIT(wait);
> + struct percpu_ida_cpu *tags;
> + unsigned long flags;
> + int tag;
> +
> + local_irq_save(flags);
> + tags = this_cpu_ptr(pool->tag_cpu);
> +
> + /* Fastpath */
> + tag = alloc_local_tag(pool, tags);
> + if (likely(tag >= 0)) {
> + local_irq_restore(flags);
> + return tag;
> + }
> +
> + while (1) {
> + spin_lock(&pool->lock);
> +
>...
2020 Aug 11
0
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...RAVIRT_SPINLOCKS, however, the warnings go away.
>>>>
>>>> Thanks for testing!
>>>>
>>>> I take it you are doing the tests in a KVM guest?
>>>
>>> Yes, correct.
>>>
>>>> If so I have a gut feeling that the use of local_irq_save() and
>>>> local_irq_restore() in kvm_wait() might be fishy. I might be completely
>>>> wrong here, though.
>>>
>>> Happy to help debug more, although I might need patches or pointers
>>> what to play with.
>>>
>>>> BTW, I thi...
2013 Aug 21
1
[PATCH-v3 1/4] idr: Percpu ida
...39;t passed
> + * __GFP_WAIT, of course).
> + *
> + * Will not fail if passed __GFP_WAIT.
> + */
> +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
> +{
> + DEFINE_WAIT(wait);
> + struct percpu_ida_cpu *tags;
> + unsigned long flags;
> + int tag;
> +
> + local_irq_save(flags);
> + tags = this_cpu_ptr(pool->tag_cpu);
You could drop this_cpu_ptr if you pass pool->tag_cpu to alloc_local_tag.
> +/**
> + * percpu_ida_free - free a tag
> + * @pool: pool @tag was allocated from
> + * @tag: a tag previously allocated with percpu_ida_alloc()
> +...
2013 Aug 21
1
[PATCH-v3 1/4] idr: Percpu ida
...39;t passed
> + * __GFP_WAIT, of course).
> + *
> + * Will not fail if passed __GFP_WAIT.
> + */
> +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
> +{
> + DEFINE_WAIT(wait);
> + struct percpu_ida_cpu *tags;
> + unsigned long flags;
> + int tag;
> +
> + local_irq_save(flags);
> + tags = this_cpu_ptr(pool->tag_cpu);
You could drop this_cpu_ptr if you pass pool->tag_cpu to alloc_local_tag.
> +/**
> + * percpu_ida_free - free a tag
> + * @pool: pool @tag was allocated from
> + * @tag: a tag previously allocated with percpu_ida_alloc()
> +...
2013 Aug 28
2
[PATCH-v3 1/4] idr: Percpu ida
...> > > +
> > > + spin_unlock(&pool->lock);
> > > + local_irq_restore(flags);
> > > +
> > > + if (tag >= 0 || !(gfp & __GFP_WAIT))
> > > + break;
> > > +
> > > + schedule();
> > > +
> > > + local_irq_save(flags);
> > > + tags = this_cpu_ptr(pool->tag_cpu);
> > > + }
> >
> > What guarantees that this wait will terminate?
>
> It seems fairly clear to me from the break statement a couple lines up;
> if we were passed __GFP_WAIT we terminate iff we succesful...
2013 Aug 28
2
[PATCH-v3 1/4] idr: Percpu ida
...> > > +
> > > + spin_unlock(&pool->lock);
> > > + local_irq_restore(flags);
> > > +
> > > + if (tag >= 0 || !(gfp & __GFP_WAIT))
> > > + break;
> > > +
> > > + schedule();
> > > +
> > > + local_irq_save(flags);
> > > + tags = this_cpu_ptr(pool->tag_cpu);
> > > + }
> >
> > What guarantees that this wait will terminate?
>
> It seems fairly clear to me from the break statement a couple lines up;
> if we were passed __GFP_WAIT we terminate iff we succesful...
2020 Aug 07
0
[PATCH] x86/paravirt: Add missing noinstr to arch_local*() helpers
...t;>> On Thu, Aug 06, 2020 at 01:32PM +0200, peterz at infradead.org wrote:
>>>>>>>> On Thu, Aug 06, 2020 at 09:47:23AM +0200, Marco Elver wrote:
>>>>>>>>> Testing my hypothesis that raw then nested non-raw
>>>>>>>>> local_irq_save/restore() breaks IRQ state tracking -- see the reproducer
>>>>>>>>> below. This is at least 1 case I can think of that we're bound to hit.
>>>>>>> ...
>>>>>>>>
>>>>>>>> /me goes ponder things...
>...
2018 Nov 06
0
[PATCH v15 23/26] sched: early boot clock
...; +
> + /*
> + * Set __gtod_offset such that once we mark sched_clock_running,
> + * sched_clock_tick() continues where sched_clock() left off.
> + *
> + * Even if TSC is buggered, we're still UP at this point so it
> + * can't really be out of sync.
> + */
> + local_irq_save(flags);
> + __sched_clock_gtod_offset();
> + local_irq_restore(flags);
> +
> sched_clock_running = 1;
> +
> + /* Now that sched_clock_running is set adjust scd */
> + local_irq_save(flags);
> + sched_clock_tick();
> + local_irq_restore(flags);
> }
> /*
> *...
2013 Aug 16
6
[PATCH-v3 0/4] target/vhost-scsi: Add per-cpu ida tag pre-allocation for v3.12
From: Nicholas Bellinger <nab at linux-iscsi.org>
Hi folks,
This is an updated series for adding tag pre-allocation support of
target fabric descriptor memory, utilizing Kent's latest per-cpu ida
bits here, along with Christoph Lameter's latest comments:
[PATCH 04/10] idr: Percpu ida
http://marc.info/?l=linux-kernel&m=137160026006974&w=2
The first patch is a
2013 Aug 16
6
[PATCH-v3 0/4] target/vhost-scsi: Add per-cpu ida tag pre-allocation for v3.12
From: Nicholas Bellinger <nab at linux-iscsi.org>
Hi folks,
This is an updated series for adding tag pre-allocation support of
target fabric descriptor memory, utilizing Kent's latest per-cpu ida
bits here, along with Christoph Lameter's latest comments:
[PATCH 04/10] idr: Percpu ida
http://marc.info/?l=linux-kernel&m=137160026006974&w=2
The first patch is a
2020 Sep 15
0
[PATCH RFC v1 09/18] x86/hyperv: provide a bunch of helper functions
..._pages -= counts[i];
> + i++;
So here we believe we will never overrun the 2048 bytes we 'allocated'
for 'counts' above. While 'if (num_pages > HV_DEPOSIT_MAX)' presumably
guarantees that, this is not really obvious.
> + num_allocations++;
> + }
> +
> + local_irq_save(flags);
> +
> + input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
> +
> + input_page->partition_id = partition_id;
> +
> + /* Populate gpa_page_list - these will fit on the input page */
> + for (i = 0, page_count = 0; i < num_allocations; ++i) {
> + base_pfn = page...