assign_irq_vector will stop before first_system_vector.
also it will not vector that is set in used_vectors.
used_vectors is used to track non per_cpu irq_vector in vector_irq.
It include first 32 exception [0,1f) and system vector near 0xfe.
and IA32_SYSCALL_VECTOR (0x80), IRQ_MOVE_CLEANUP_VECTOR (0x20).
So add checking for them for counting avaiable vectors.
-v2: fix compiling problem.
Signed-off-by: Yinghai Lu <[email protected]>
---
arch/x86/kernel/irq.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
Index: linux-2.6/arch/x86/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/irq.c
+++ linux-2.6/arch/x86/kernel/irq.c
@@ -17,6 +17,7 @@
#include <asm/idle.h>
#include <asm/mce.h>
#include <asm/hw_irq.h>
+#include <asm/desc.h>
#define CREATE_TRACE_POINTS
#include <asm/trace/irq_vectors.h>
@@ -321,8 +322,19 @@ int check_irq_vectors_for_cpu_disable(vo
for_each_online_cpu(cpu) {
if (cpu == this_cpu)
continue;
- for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
- vector++) {
+
+ /*
+ * assign_irq_vector() only use vector under
+ * first_system_vector and not set in used_vectors bitmask.
+ * used_vectors could have bits set for
+ * IA32_SYSCALL_VECTOR (0x80)
+ * IRQ_MOVE_CLEANUP_VECTOR (0x20)
+ */
+ for (vector = FIRST_EXTERNAL_VECTOR;
+ vector < first_system_vector; vector++) {
+ if (test_bit(vector, used_vectors))
+ continue;
+
if (per_cpu(vector_irq, cpu)[vector] < 0)
count++;
}
On 01/26/2014 03:50 PM, Yinghai Lu wrote:
> assign_irq_vector will stop before first_system_vector.
> also it will not vector that is set in used_vectors.
>
> used_vectors is used to track non per_cpu irq_vector in vector_irq.
> It include first 32 exception [0,1f) and system vector near 0xfe.
> and IA32_SYSCALL_VECTOR (0x80), IRQ_MOVE_CLEANUP_VECTOR (0x20).
>
> So add checking for them for counting avaiable vectors.
>
Yinghai, no objection to the patch ... but how about
used_vectors is a bitmap for global irqs; it tracks the non per_cpu
irq_vectors in vector_irq. used_vectors contains information on the first 32
exceptions (0 to 0x1f), the system vectors near the first system vector
(0xfe), the IA32_SYSCALL_VECTOR (0x80), and the IRQ_MOVE_CLEANUP_VECTOR (0x20)
assign_irq_vectors() assigns vectors up to first_system_vector (0xfe) and
sets the used_vectors bit for each assigned vector. Currently, the
IRQ checking code only scans from the FIRST_EXTERNAL_VECTOR to the end of
the vectors. This patch modifies the code to scan to first_system_vector
and do a test on the used_vectors bitmap.
... and ...
> -v2: fix compiling problem.
>
> Signed-off-by: Yinghai Lu <[email protected]>
>
> ---
> arch/x86/kernel/irq.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> Index: linux-2.6/arch/x86/kernel/irq.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/kernel/irq.c
> +++ linux-2.6/arch/x86/kernel/irq.c
> @@ -17,6 +17,7 @@
> #include <asm/idle.h>
> #include <asm/mce.h>
> #include <asm/hw_irq.h>
> +#include <asm/desc.h>
>
> #define CREATE_TRACE_POINTS
> #include <asm/trace/irq_vectors.h>
> @@ -321,8 +322,19 @@ int check_irq_vectors_for_cpu_disable(vo
> for_each_online_cpu(cpu) {
> if (cpu == this_cpu)
> continue;
> - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
> - vector++) {
> +
> + /*
> + * assign_irq_vector() only use vector under
> + * first_system_vector and not set in used_vectors bitmask.
> + * used_vectors could have bits set for
> + * IA32_SYSCALL_VECTOR (0x80)
> + * IRQ_MOVE_CLEANUP_VECTOR (0x20)
> + */
+ /*
+ * assign_irq_vector() will only scan non per_cpu vectors from
+ * FIRST_EXTERNAL_VECTOR to first_system_vector (0xfe) and not
+ * set in used_vectors bitmask. This takes into account
+ * the IA32_SYSCALL_VECTOR and the IRQ_MOVE_CLEANUP_VECTOR,
+ * which should not be counted.
+ */
... what do you think?
P.
> + for (vector = FIRST_EXTERNAL_VECTOR;
> + vector < first_system_vector; vector++) {
> + if (test_bit(vector, used_vectors))
> + continue;
> +
> if (per_cpu(vector_irq, cpu)[vector] < 0)
> count++;
> }
On Tue, Jan 28, 2014 at 10:43 AM, Prarit Bhargava <[email protected]> wrote:
>
>
> On 01/26/2014 03:50 PM, Yinghai Lu wrote:
>> assign_irq_vector will stop before first_system_vector.
>> also it will not vector that is set in used_vectors.
>>
>> used_vectors is used to track non per_cpu irq_vector in vector_irq.
>> It include first 32 exception [0,1f) and system vector near 0xfe.
>> and IA32_SYSCALL_VECTOR (0x80), IRQ_MOVE_CLEANUP_VECTOR (0x20).
>>
>> So add checking for them for counting avaiable vectors.
>>
>
> Yinghai, no objection to the patch ... but how about
>
>
> used_vectors is a bitmap for global irqs; it tracks the non per_cpu
> irq_vectors in vector_irq. used_vectors contains information on the first 32
> exceptions (0 to 0x1f), the system vectors near the first system vector
> (0xfe), the IA32_SYSCALL_VECTOR (0x80), and the IRQ_MOVE_CLEANUP_VECTOR (0x20)
>
> assign_irq_vectors() assigns vectors up to first_system_vector (0xfe) and
> sets the used_vectors bit for each assigned vector.
No, assign_irq_vectors will not touch used_vectors.
> Currently, the
> IRQ checking code only scans from the FIRST_EXTERNAL_VECTOR to the end of
> the vectors. This patch modifies the code to scan to first_system_vector
> and do a test on the used_vectors bitmap.
first_system_vector start from 0xfe, and will be updated ....would end up with
0xf7.
>
>
> ... and ...
>
>> -v2: fix compiling problem.
>>
>> Signed-off-by: Yinghai Lu <[email protected]>
>>
>> ---
>> arch/x86/kernel/irq.c | 16 ++++++++++++++--
>> 1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> Index: linux-2.6/arch/x86/kernel/irq.c
>> ===================================================================
>> --- linux-2.6.orig/arch/x86/kernel/irq.c
>> +++ linux-2.6/arch/x86/kernel/irq.c
>> @@ -17,6 +17,7 @@
>> #include <asm/idle.h>
>> #include <asm/mce.h>
>> #include <asm/hw_irq.h>
>> +#include <asm/desc.h>
>>
>> #define CREATE_TRACE_POINTS
>> #include <asm/trace/irq_vectors.h>
>> @@ -321,8 +322,19 @@ int check_irq_vectors_for_cpu_disable(vo
>> for_each_online_cpu(cpu) {
>> if (cpu == this_cpu)
>> continue;
>> - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
>> - vector++) {
>> +
>> + /*
>> + * assign_irq_vector() only use vector under
>> + * first_system_vector and not set in used_vectors bitmask.
>> + * used_vectors could have bits set for
>> + * IA32_SYSCALL_VECTOR (0x80)
>> + * IRQ_MOVE_CLEANUP_VECTOR (0x20)
>> + */
>
>
> + /*
> + * assign_irq_vector() will only scan non per_cpu vectors from
> + * FIRST_EXTERNAL_VECTOR to first_system_vector (0xfe) and not
> + * set in used_vectors bitmask. This takes into account
> + * the IA32_SYSCALL_VECTOR and the IRQ_MOVE_CLEANUP_VECTOR,
> + * which should not be counted.
> + */
>
> ... what do you think?
>
will send updated version.
Thanks
Yinghai