As what Pavel Machek reported [1], some userspace applications depend on bogomips showed by /proc/cpuinfo.
Although there is much less legacy impact on aarch64 than arm, but it does break libvirt.
Basically, this patch reverts commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with some tweak due to context change.
[1] https://lkml.org/lkml/2015/1/4/132
Acked-by: Will Deacon will.deacon@arm.com Cc: stable@vger.kernel.org #3.12+ Signed-off-by: Yang Shi yang.shi@linaro.org --- V2 --> V1: * Remove double new line and unnecessary bogomips sum info
arch/arm64/kernel/cpuinfo.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 706679d..212ae63 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -30,6 +30,7 @@ #include <linux/seq_file.h> #include <linux/sched.h> #include <linux/smp.h> +#include <linux/delay.h>
/* * In case the boot CPU is hotpluggable, we record its initial state and @@ -112,6 +113,10 @@ static int c_show(struct seq_file *m, void *v) */ seq_printf(m, "processor\t: %d\n", i);
+ seq_printf(m, "BogoMIPS\t: %lu.%02lu\n", + loops_per_jiffy / (500000UL/HZ), + loops_per_jiffy / (5000UL/HZ) % 100); + /* * Dump out the common processor features in a single line. * Userspace should read the hwcaps with getauxval(AT_HWCAP)
On Wed, Nov 18, 2015 at 10:48:55AM -0800, Yang Shi wrote:
As what Pavel Machek reported [1], some userspace applications depend on bogomips showed by /proc/cpuinfo.
Although there is much less legacy impact on aarch64 than arm, but it does break libvirt.
Basically, this patch reverts commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with some tweak due to context change.
[1] https://lkml.org/lkml/2015/1/4/132
Acked-by: Will Deacon will.deacon@arm.com Cc: stable@vger.kernel.org #3.12+ Signed-off-by: Yang Shi yang.shi@linaro.org
Patch applied as a fix for stable, basically returning back to the pre-3.12 behaviour. If there is a need for some more useful information here, it can be done as an additional patch, though without cc: stable.
Thanks.
On 11/19/2015 9:59 AM, Catalin Marinas wrote:
On Wed, Nov 18, 2015 at 10:48:55AM -0800, Yang Shi wrote:
As what Pavel Machek reported [1], some userspace applications depend on bogomips showed by /proc/cpuinfo.
Although there is much less legacy impact on aarch64 than arm, but it does break libvirt.
Basically, this patch reverts commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with some tweak due to context change.
[1] https://lkml.org/lkml/2015/1/4/132
Acked-by: Will Deacon will.deacon@arm.com Cc: stable@vger.kernel.org #3.12+ Signed-off-by: Yang Shi yang.shi@linaro.org
Patch applied as a fix for stable, basically returning back to the pre-3.12 behaviour. If there is a need for some more useful information here, it can be done as an additional patch, though without cc: stable.
Thanks. This approach sounds safer to usersapce.
Yang
Thanks.
linaro-kernel@lists.linaro.org
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Catalin Marinas -
Shi, Yang -
Yang Shi