Messages in this thread | | | Date | Sat, 29 Jan 2005 14:35:51 +0300 | From | Oleg Nesterov <> | Subject | Re: [PATCH 3/4] readahead: factor out duplicated code |
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> This patch introduces make_ahead_window() function for > simplification of page_cache_readahead.
If you will count this patch acceptable, I'll rediff it against next mm iteration.
For your convenience here is the code with the patch applied.
int make_ahead_window(mapping, filp, ra, int force) { int block, ret;
ra->ahead_size = get_next_ra_size(ra); ra->ahead_start = ra->start + ra->size;
block = force || (ra->prev_page >= ra->ahead_start); ret = blockable_page_cache_readahead(mapping, filp, ra->ahead_start, ra->ahead_size, ra, block);
if (!ret && !force) { ra->ahead_start = 0; ra->ahead_size = 0; }
return ret; }
unsigned long page_cache_readahead(mapping, ra, filp, offset, req_size) { unsigned long max, newsize = req_size; int sequential = (offset == ra->prev_page + 1);
if (offset == ra->prev_page && req_size == 1 && ra->size != 0) goto out;
ra->prev_page = offset; max = get_max_readahead(ra); newsize = min(req_size, max);
if (newsize == 0 || (ra->flags & RA_FLAG_INCACHE)) { newsize = 1; goto out; }
ra->prev_page += newsize - 1;
if ((ra->size == 0 && offset == 0) || (ra->size == -1 && sequential)) { ra->size = get_init_ra_size(newsize, max); ra->start = offset; if (!blockable_page_cache_readahead(mapping, filp, offset, ra->size, ra, 1)) goto out;
if (req_size >= max) make_ahead_window(mapping, filp, ra, 1);
goto out; }
if (!sequential || (ra->size == 0)) { ra_off(ra); blockable_page_cache_readahead(mapping, filp, offset, newsize, ra, 1); goto out; }
if (ra->ahead_start == 0) { if (!make_ahead_window(mapping, filp, ra, 0)) goto out; }
if (ra->prev_page >= ra->ahead_start) { ra->start = ra->ahead_start; ra->size = ra->ahead_size; make_ahead_window(mapping, filp, ra, 0); } out: return newsize; } - 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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