On Wed, Jan 13, 2021 at 1:33 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
>
> Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE.
> We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom
> call in do_tcp_getsockopt using the on-stack data. This removes
> 3% overhead for locking/unlocking the socket.
>
> Without this patch:
> 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt
> |
> --3.30%--__cgroup_bpf_run_filter_getsockopt
> |
> --0.81%--__kmalloc
>
> With the patch applied:
> 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern
>
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> Cc: Martin KaFai Lau <kafai@xxxxxx>
> Cc: Song Liu <songliubraving@xxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Acked-by: Martin KaFai Lau <kafai@xxxxxx>
Few issues in this patch and the patch 2 doesn't apply:
Switched to a new branch 'tmp'
Applying: bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE
.git/rebase-apply/patch:295: trailing whitespace.
#endif
.git/rebase-apply/patch:306: trailing whitespace.
union tcp_word_hdr {
.git/rebase-apply/patch:309: trailing whitespace.
};
.git/rebase-apply/patch:311: trailing whitespace.
#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
.git/rebase-apply/patch:313: trailing whitespace.
enum {
warning: squelched 1 whitespace error
warning: 6 lines add whitespace errors.
Applying: bpf: Try to avoid kzalloc in cgroup/{s,g}etsockopt
error: patch failed: kernel/bpf/cgroup.c:1390
error: kernel/bpf/cgroup.c: patch does not apply
Patch failed at 0002 bpf: Try to avoid kzalloc in cgroup/{s,g}etsockopt
