Messages in this thread | | | Date | Sat, 20 Dec 2008 17:31:25 +0800 | From | Lai Jiangshan <> | Subject | Re: [PATCH] ring_bufer: fix BUF_PAGE_SIZE |
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Ingo Molnar wrote: > * Lai Jiangshan <laijs@cn.fujitsu.com> wrote: > >> impact: make BUF_PAGE_SIZE changeable. >> >> Except allocating/freeing page and the code using PAGE_MASK, >> all code expect buffer_page's length is BUF_PAGE_SIZE. >> >> This patch make this behavior more concordant. >> [...] > > hm, why? Non-order-0 allocations are pretty evil - why would we ever want > to do them? > > Ingo >
I think since we introduce BUF_PAGE_SIZE instead of PAGE_SIZE for buffer_page, we should make it changeable. We can use Non-order-0 allocations, but it doesn't mean we have to use Non-order-0 allocations.
In the old codes, these lines confuse me: return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); addr &= PAGE_MASK; This patch mostly make the codes concordant.
Lai
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