- offset &= chanb->buf_size - 1;
- sbidx = offset >> chanb->subbuf_size_order;
- id = shmp_index(handle, bufb->buf_wsb, sbidx)->id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = shmp_index(handle, bufb->array, sb_bindex);
- if (caa_unlikely(!rpages))
- return;
- CHAN_WARN_ON(ctx->chan,
- config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));