Messages in this thread Patch in this message | | | Date | Fri, 09 Jun 2006 16:08:04 +0800 | From | Wu Fengguang <> | Subject | [PATCH 3/5] readahead: call scheme - no fastcall for readahead_cache_hit() |
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Remove 'fastcall' directive for readahead_cache_hit().
It leads to unfavorable performance in the following micro benchmark on i386 with CONFIG_REGPARM=n:
Command: time cp cold /dev/null
Summary: user sys cpu total no-fastcall 1.24 24.88 90.9 28.57 fastcall 1.16 25.69 91.5 29.23
Details: without fastcall: cp cold /dev/null 1.27s user 24.63s system 91% cpu 28.348 total cp cold /dev/null 1.17s user 25.09s system 91% cpu 28.653 total cp cold /dev/null 1.24s user 24.75s system 91% cpu 28.448 total cp cold /dev/null 1.20s user 25.04s system 91% cpu 28.614 total cp cold /dev/null 1.31s user 24.67s system 91% cpu 28.499 total cp cold /dev/null 1.30s user 24.87s system 91% cpu 28.530 total cp cold /dev/null 1.26s user 24.84s system 91% cpu 28.542 total cp cold /dev/null 1.16s user 25.15s system 90% cpu 28.925 total
with fastcall: cp cold /dev/null 1.16s user 26.39s system 91% cpu 30.061 total cp cold /dev/null 1.25s user 26.53s system 91% cpu 30.378 total cp cold /dev/null 1.10s user 25.32s system 92% cpu 28.679 total cp cold /dev/null 1.15s user 25.20s system 91% cpu 28.747 total cp cold /dev/null 1.19s user 25.38s system 92% cpu 28.841 total cp cold /dev/null 1.11s user 25.75s system 92% cpu 29.126 total cp cold /dev/null 1.17s user 25.49s system 91% cpu 29.042 total cp cold /dev/null 1.17s user 25.49s system 92% cpu 28.970 total
Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn> ---
--- linux-2.6.17-rc5-mm2.orig/include/linux/mm.h +++ linux-2.6.17-rc5-mm2/include/linux/mm.h @@ -1074,7 +1074,7 @@ page_cache_readahead_adaptive(struct add struct file_ra_state *ra, struct file *filp, struct page *prev_page, struct page *page, pgoff_t first_index, pgoff_t index, pgoff_t last_index); -void fastcall readahead_cache_hit(struct file_ra_state *ra, struct page *page); +void readahead_cache_hit(struct file_ra_state *ra, struct page *page);
#ifdef CONFIG_ADAPTIVE_READAHEAD extern int readahead_ratio; --- linux-2.6.17-rc5-mm2.orig/mm/readahead.c +++ linux-2.6.17-rc5-mm2/mm/readahead.c @@ -1916,7 +1916,7 @@ readit: * readahead_cache_hit() is the feedback route of the adaptive read-ahead * logic. It must be called on every access on the read-ahead pages. */ -void fastcall readahead_cache_hit(struct file_ra_state *ra, struct page *page) +void readahead_cache_hit(struct file_ra_state *ra, struct page *page) { if (PageActive(page) || PageReferenced(page)) return; -- - 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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