Linux Virtualization - May 2016 - [PATCH] tools/virtio/ringtest: fix run-on-all.sh to work without /dev/cpu

Having typical usage example in the README file is more convinient than in
the git history...

Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
---
 tools/virtio/ringtest/README | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/virtio/ringtest/README b/tools/virtio/ringtest/README
index 34e94c4..d83707a 100644
--- a/tools/virtio/ringtest/README
+++ b/tools/virtio/ringtest/README
@@ -1,2 +1,6 @@
 Partial implementation of various ring layouts, useful to tune virtio design.
 Uses shared memory heavily.
+
+Typical use:
+
+# sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring
-- 
1.9.1

/dev/cpu is only available on x86 with certain modules (e.g. msr) enabled.
Using /proc/cpuinfo to get processors count is more portable.

Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
---
 tools/virtio/ringtest/run-on-all.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/virtio/ringtest/run-on-all.sh
b/tools/virtio/ringtest/run-on-all.sh
index 52b0f71..38ccfa3 100755
--- a/tools/virtio/ringtest/run-on-all.sh
+++ b/tools/virtio/ringtest/run-on-all.sh
@@ -3,10 +3,10 @@
 #use last CPU for host. Why not the first?
 #many devices tend to use cpu0 by default so
 #it tends to be busier
-HOST_AFFINITY=$(cd /dev/cpu; ls|grep -v '[a-z]'|sort -n|tail -1)
+HOST_AFFINITY=$(($(grep -c processor /proc/cpuinfo) - 1))
 
 #run command on all cpus
-for cpu in $(cd /dev/cpu; ls|grep -v '[a-z]'|sort -n);
+for cpu in $(seq 0 $HOST_AFFINITY)
 do
 	#Don't run guest and host on same CPU
 	#It actually works ok if using signalling
-- 
1.9.1

On Wed,  4 May 2016 09:12:56 +0300
Mike Rapoport <rppt at linux.vnet.ibm.com> wrote:
> /dev/cpu is only available on x86 with certain modules (e.g. msr) enabled.
> Using /proc/cpuinfo to get processors count is more portable.
> 
> Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> ---
>  tools/virtio/ringtest/run-on-all.sh | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/virtio/ringtest/run-on-all.sh
b/tools/virtio/ringtest/run-on-all.sh
> index 52b0f71..38ccfa3 100755
> --- a/tools/virtio/ringtest/run-on-all.sh
> +++ b/tools/virtio/ringtest/run-on-all.sh
> @@ -3,10 +3,10 @@
>  #use last CPU for host. Why not the first?
>  #many devices tend to use cpu0 by default so
>  #it tends to be busier
> -HOST_AFFINITY=$(cd /dev/cpu; ls|grep -v '[a-z]'|sort -n|tail -1)
> +HOST_AFFINITY=$(($(grep -c processor /proc/cpuinfo) - 1))
>  
>  #run command on all cpus
> -for cpu in $(cd /dev/cpu; ls|grep -v '[a-z]'|sort -n);
> +for cpu in $(seq 0 $HOST_AFFINITY)
>  do
>  	#Don't run guest and host on same CPU
>  	#It actually works ok if using signalling
As you're touching this anyway: Is there any way to avoid the
architecture-specific /proc/cpuinfo and do whatever lscpu does?

Michael,

Any updates on this?

On Wed, May 04, 2016 at 09:12:55AM +0300, Mike Rapoport
wrote:
> Having typical usage example in the README file is more convinient than in
> the git history...
> 
> Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> ---
>  tools/virtio/ringtest/README | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/virtio/ringtest/README b/tools/virtio/ringtest/README
> index 34e94c4..d83707a 100644
> --- a/tools/virtio/ringtest/README
> +++ b/tools/virtio/ringtest/README
> @@ -1,2 +1,6 @@
>  Partial implementation of various ring layouts, useful to tune virtio
design.
>  Uses shared memory heavily.
> +
> +Typical use:
> +
> +# sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring
> -- 
> 1.9.1
>

Ping?

On Tue, May 24, 2016 at 03:41:04PM +0300, Mike Rapoport
wrote:
> Michael,
> 
> Any updates on this?
> 
> On Wed, May 04, 2016 at 09:12:55AM +0300, Mike Rapoport wrote:
> > Having typical usage example in the README file is more convinient
than in
> > the git history...
> > 
> > Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> > ---
> >  tools/virtio/ringtest/README | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/tools/virtio/ringtest/README
b/tools/virtio/ringtest/README
> > index 34e94c4..d83707a 100644
> > --- a/tools/virtio/ringtest/README
> > +++ b/tools/virtio/ringtest/README
> > @@ -1,2 +1,6 @@
> >  Partial implementation of various ring layouts, useful to tune virtio
design.
> >  Uses shared memory heavily.
> > +
> > +Typical use:
> > +
> > +# sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring
> > -- 
> > 1.9.1
> > 
> 
> --
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