As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com --- include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask, * cover a worst-case of every other cpu being on one of two nodes for a * very large NR_CPUS. * - * Use PAGE_SIZE as a minimum for smaller configurations. + * Use PAGE_SIZE as a minimum for smaller configurations while avoiding + * unsigned comparison to -1. */ -#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE) #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE)
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus
Yeah, lots of CPUs! :)
-r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE) #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) -- 2.31.1
Nice catch. What type of systems did you run this on to verify it will work?
thanks,
greg k-h
On Tue, Sep 06, 2022 at 07:02:37PM +0200 Greg Kroah-Hartman wrote:
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus
Yeah, lots of CPUs! :)
Yep, apparently things like lscpu fail with this size.
-r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE) #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) -- 2.31.1
Nice catch. What type of systems did you run this on to verify it will work?
Feng ran it on his 2 cpu laptop. I ran it on my usual test bed (80 cpus) but configured both with NR_CPUS at 8192 and at 2.
It's not really dependent on the actual system. It's a compile time config option. I failed to set it small when testing the first one.
The fix here is just maths :)
With NR_CPUS == 2:
# ls -l /sys/devices/system/cpu/cpu0/topology/ total 0 -r--r--r--. 1 root root 4096 Sep 6 11:40 cluster_cpus -r--r--r--. 1 root root 4096 Sep 6 11:40 cluster_cpus_list -r--r--r--. 1 root root 4096 Sep 6 11:40 cluster_id -r--r--r--. 1 root root 4096 Sep 6 11:40 core_cpus -r--r--r--. 1 root root 4096 Sep 6 11:40 core_cpus_list -r--r--r--. 1 root root 4096 Sep 6 11:40 core_id -r--r--r--. 1 root root 4096 Sep 6 11:29 core_siblings -r--r--r--. 1 root root 4096 Sep 6 11:40 core_siblings_list ...
Cheers, Phil
thanks,
greg k-h
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \
Maybe it would be easier to read with less braces and '>=' instead of '>'? #define CPUMAP_FILE_MAX_BYTES \ (NR_CPUS * 9 / 32 >= PAGE_SIZE ? NR_CPUS * 9 / 32 - 1 : PAGE_SIZE)
Anyways, this is a good catch. If you think it doesn't worth an update, I can take it in bitmap-for-next as-is.
? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)#define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) -- 2.31.1
On Tue, Sep 06, 2022 at 11:09:54AM -0700, Yury Norov wrote:
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \
Maybe it would be easier to read with less braces and '>=' instead of '>'? #define CPUMAP_FILE_MAX_BYTES \ (NR_CPUS * 9 / 32 >= PAGE_SIZE ? NR_CPUS * 9 / 32 - 1 : PAGE_SIZE)
Anyways, this is a good catch. If you think it doesn't worth an update, I can take it in bitmap-for-next as-is.
Ah, I screwed in math. '>=' wouldn't work of course...
On Tue, Sep 06, 2022 at 11:09:53AM -0700 Yury Norov wrote:
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \
Maybe it would be easier to read with less braces and '>=' instead of '>'? #define CPUMAP_FILE_MAX_BYTES \ (NR_CPUS * 9 / 32 >= PAGE_SIZE ? NR_CPUS * 9 / 32 - 1 : PAGE_SIZE)
Anyways, this is a good catch. If you think it doesn't worth an update, I can take it in bitmap-for-next as-is.
It would work as #define CPUMAP_FILE_MAX_BYTES (((NR_CPUS * 9)/32 > PAGE_SIZE) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)
Since 4097 > PAGE_SIZE and then you'd get PAGE_SIZE anyway. That is we could just leave the 1 out of the inequality completely.
If I recall at least some of the parens are needed to make the compiler happy.
I can resend with the above if you want.
Cheers, Phil
? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)#define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) -- 2.31.1
On Tue, Sep 06, 2022 at 02:57:41PM -0400, Phil Auld wrote:
On Tue, Sep 06, 2022 at 11:09:53AM -0700 Yury Norov wrote:
On Tue, Sep 06, 2022 at 12:04:30PM -0400, Phil Auld wrote:
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3. This leads to very large file sizes:
topology$ ls -l total 0 -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 core_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list -r--r--r-- 1 root root 4096 Sep 5 11:59 die_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus -r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list -r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id -r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings -r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured to a small value.
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist") Reported-by: feng xiangjun fengxj325@gmail.com Signed-off-by: Phil Auld pauld@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: Yury Norov yury.norov@gmail.com Cc: stable@vger.kernel.org Cc: feng xiangjun fengxj325@gmail.com
include/linux/cpumask.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..7b1349612d6d 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
- cover a worst-case of every other cpu being on one of two nodes for a
- very large NR_CPUS.
- Use PAGE_SIZE as a minimum for smaller configurations.
- Use PAGE_SIZE as a minimum for smaller configurations while avoiding
*/
- unsigned comparison to -1.
-#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32) > PAGE_SIZE + 1) \
Maybe it would be easier to read with less braces and '>=' instead of '>'? #define CPUMAP_FILE_MAX_BYTES \ (NR_CPUS * 9 / 32 >= PAGE_SIZE ? NR_CPUS * 9 / 32 - 1 : PAGE_SIZE)
Anyways, this is a good catch. If you think it doesn't worth an update, I can take it in bitmap-for-next as-is.
It would work as #define CPUMAP_FILE_MAX_BYTES (((NR_CPUS * 9)/32 > PAGE_SIZE) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)
Since 4097 > PAGE_SIZE and then you'd get PAGE_SIZE anyway. That is we could just leave the 1 out of the inequality completely.
If I recall at least some of the parens are needed to make the compiler happy.
I can resend with the above if you want.
Yes, please
linux-stable-mirror@lists.linaro.org
-
Greg Kroah-Hartman -
Phil Auld -
Yury Norov