Messages in this thread | | | Date | Thu, 30 Mar 2006 18:59:56 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] splice: add support for SPLICE_F_MOVE flag |
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Andrew Morton <akpm@osdl.org> wrote: > > static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, > > struct pipe_buffer *buf) > > { > > - unlock_page(buf->page); > > + if (!buf->stolen) > > + unlock_page(buf->page); > > kunmap(buf->page); > > } > > There go our chances of ever getting rid of kmap(). Is it not feasible to > use atomic kmaps throughout this code?
What are the kmaps for, anyway? afaict they're doing the kmap-the-page-while-we-run-some-a_ops thing which ceased being a requirement 3-4 years ago.
The general approach we should take is that the code which actually modifies a page's contents is the code which is responsible for kmapping that page. Use an atomic kmap, memcpy-or-memset, atomic kunmap. Just four or five lines.
If we can do that, pipe_buf_operations.map/unmap can be removed. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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