Messages in this thread | | | Date | Thu, 11 Jun 2009 11:25:48 +0800 | From | Lai Jiangshan <> | Subject | Re: [PATCH 1/3] ring-buffer: make the buffer a true circular link list |
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Steven Rostedt wrote: > On Thu, 11 Jun 2009, Lai Jiangshan wrote: > >>> - list_splice(&pages, head); >>> + /* >>> + * The ring buffer page list is a circular list that does not >>> + * start and end with a list head. All page list items point to >>> + * other pages. Remove one of the pages, init its list head, >>> + * and use list splice to move the rest of the pages to it. >>> + */ >>> + bpage = list_entry(pages.next, struct buffer_page, list); >>> + list_del_init(&bpage->list); >>> + cpu_buffer->pages = &bpage->list; >>> + >>> + list_splice(&pages, cpu_buffer->pages); >>> + >> Is it proper? >> >> cpu_buffer->pages = pages.next; >> list_del(&pages); >> > > Not sure what you are asking here? >
I'm not sure whether these 4 lines: bpage = list_entry(pages.next, struct buffer_page, list); list_del_init(&bpage->list); cpu_buffer->pages = &bpage->list;
list_splice(&pages, cpu_buffer->pages); equal to these 2 lines: cpu_buffer->pages = pages.next; list_del(&pages);
If there are equivalent, I think the second one are simpler. It may be not a really necessarily cleanup.
What I asked is: if there are equivalent, could you use these two line: cpu_buffer->pages = pages.next; list_del(&pages);
Lai.
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