| Message ID | 20220707080245.180525-1-atenart@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 40ad0a52ef5d2c3379bb9b6af06c8029ac6c875d |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] Documentation: add a description for net.core.high_order_alloc_disable | expand |
On Thu, Jul 7, 2022 at 10:02 AM Antoine Tenart <atenart@kernel.org> wrote: > > A description is missing for the net.core.high_order_alloc_disable > option in admin-guide/sysctl/net.rst ; add it. The above sysctl option > was introduced by commit ce27ec60648d ("net: add high_order_alloc_disable > sysctl/static key"). > > Thanks to Eric for running again the benchmark cited in the above > commit, showing this knob is now mostly of historical importance. > > Cc: Eric Dumazet <edumazet@google.com> > Signed-off-by: Antoine Tenart <atenart@kernel.org> > --- Reviewed-by: Eric Dumazet <edumazet@google.com>
Hello: This patch was applied to netdev/net-next.git (master) by Jakub Kicinski <kuba@kernel.org>: On Thu, 7 Jul 2022 10:02:45 +0200 you wrote: > A description is missing for the net.core.high_order_alloc_disable > option in admin-guide/sysctl/net.rst ; add it. The above sysctl option > was introduced by commit ce27ec60648d ("net: add high_order_alloc_disable > sysctl/static key"). > > Thanks to Eric for running again the benchmark cited in the above > commit, showing this knob is now mostly of historical importance. > > [...] Here is the summary with links: - [net-next,v2] Documentation: add a description for net.core.high_order_alloc_disable https://git.kernel.org/netdev/net-next/c/40ad0a52ef5d You are awesome, thank you!
diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index fcd650bdbc7e..805f2281e000 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -391,6 +391,18 @@ GRO has decided not to coalesce, it is placed on a per-NAPI list. This list is then passed to the stack when the number of segments reaches the gro_normal_batch limit. +high_order_alloc_disable +------------------------ + +By default the allocator for page frags tries to use high order pages (order-3 +on x86). While the default behavior gives good results in most cases, some users +might have hit a contention in page allocations/freeing. This was especially +true on older kernels (< 5.14) when high-order pages were not stored on per-cpu +lists. This allows to opt-in for order-0 allocation instead but is now mostly of +historical importance. + +Default: 0 + 2. /proc/sys/net/unix - Parameters for Unix domain sockets ----------------------------------------------------------
A description is missing for the net.core.high_order_alloc_disable option in admin-guide/sysctl/net.rst ; add it. The above sysctl option was introduced by commit ce27ec60648d ("net: add high_order_alloc_disable sysctl/static key"). Thanks to Eric for running again the benchmark cited in the above commit, showing this knob is now mostly of historical importance. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Antoine Tenart <atenart@kernel.org> --- Since v1: - Reworked the documentation to mention this knob is now mostly of historical importance after Eric ran again the benchmark cited in the above commit. Documentation/admin-guide/sysctl/net.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+)