| Message ID | 20231128080033.288050-4-urezki@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Reduce synchronize_rcu() latency(V3) | expand |
On Tue, Nov 28, 2023 at 09:00:29AM +0100, Uladzislau Rezki (Sony) wrote: > This commit adds rcutree.rcu_normal_wake_from_gp description > to the kernel-parameters.txt file. > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Very good, but could you please fold this into the first patch, which is the one that adds this kernel parameter? Thanx, Paul > --- > Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 0a1731a0f0ef..65bfbfb09522 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4944,6 +4944,20 @@ > this kernel boot parameter, forcibly setting it > to zero. > > + rcutree.rcu_normal_wake_from_gp= [KNL] > + Reduces a latency of synchronize_rcu() call. This approach > + maintains its own track of synchronize_rcu() callers, so it > + does not interact with regular callbacks because it does not > + use a call_rcu[_hurry]() path. Please note, this is for a > + normal grace period. > + > + How to enable it: > + > + echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp > + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1" > + > + Default is 0. > + > rcuscale.gp_async= [KNL] > Measure performance of asynchronous > grace-period primitives such as call_rcu(). > -- > 2.39.2 >
On Tue, Dec 19, 2023 at 05:17:19PM -0800, Paul E. McKenney wrote: > On Tue, Nov 28, 2023 at 09:00:29AM +0100, Uladzislau Rezki (Sony) wrote: > > This commit adds rcutree.rcu_normal_wake_from_gp description > > to the kernel-parameters.txt file. > > > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > > Very good, but could you please fold this into the first patch, which > is the one that adds this kernel parameter? > No problem :) -- Uladzislau Rezki
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0a1731a0f0ef..65bfbfb09522 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4944,6 +4944,20 @@ this kernel boot parameter, forcibly setting it to zero. + rcutree.rcu_normal_wake_from_gp= [KNL] + Reduces a latency of synchronize_rcu() call. This approach + maintains its own track of synchronize_rcu() callers, so it + does not interact with regular callbacks because it does not + use a call_rcu[_hurry]() path. Please note, this is for a + normal grace period. + + How to enable it: + + echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1" + + Default is 0. + rcuscale.gp_async= [KNL] Measure performance of asynchronous grace-period primitives such as call_rcu().
This commit adds rcutree.rcu_normal_wake_from_gp description to the kernel-parameters.txt file. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> --- Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+)