Messages in this thread | | | Date | Mon, 23 Jul 2007 20:55:35 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 03/10] readahead: combine file_ra_state.prev_index/prev_offset into prev_pos |
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On Tue, 24 Jul 2007 10:00:12 +0800 Fengguang Wu <wfg@mail.ustc.edu.cn> wrote:
> @@ -342,11 +342,9 @@ ondemand_readahead(struct address_space > bool hit_readahead_marker, pgoff_t offset, > unsigned long req_size) > { > - int max; /* max readahead pages */ > - int sequential; > - > - max = ra->ra_pages; > - sequential = (offset - ra->prev_index <= 1UL) || (req_size > max); > + int max = ra->ra_pages; /* max readahead pages */ > + pgoff_t prev_offset; > + int sequential; > > /* > * It's the expected callback offset, assume sequential access. > @@ -360,6 +358,9 @@ ondemand_readahead(struct address_space > goto readit; > } > > + prev_offset = ra->prev_pos >> PAGE_CACHE_SHIFT; > + sequential = offset - prev_offset <= 1UL || req_size > max;
It's a bit pointless using an opaque type for prev_offset here, and then encoding the knowledge that it is implemented as "unsigned long".
It's a minor thing, but perhaps just "<= 1" would make more sense here. - 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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