From: Antoine Tenart Date: Thu, 7 Jul 2022 08:02:45 +0000 (+0200) Subject: Documentation: add a description for net.core.high_order_alloc_disable X-Git-Tag: baikal/aarch64/sdk6.1~3391^2~170 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=ed19ce159488e606561a8cf6740a997e601f820f;p=kernel.git Documentation: add a description for net.core.high_order_alloc_disable 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 8973faec3a91 ("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. Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220707080245.180525-1-atenart@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index fcd650bdbc7e2..805f2281e000a 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 ----------------------------------------------------------