Commit 8f6a00c3efbfedfe0792464726c08ffe2bffdcd0 - nginx - Klaus Demo

Klaus Demo nginx / 8f6a00c

fix comment Igor Sysoev 15 years ago

1 changed file(s) with 3 addition(s) and 3 deletion(s). Raw diff Collapse all Expand all

+3

-3

src/core/ngx_crc32.c less more

12	12	* described at http://www.w3.org/TR/PNG/
13	13	*
14	14	* The 256 element lookup table takes 1024 bytes, and it may be completely
15		* cached after processing about 30-60 bytes. So for short messages
	15	* cached after processing about 30-60 bytes of data. So for short data
16	16	* we use the 16 element lookup table that takes only 64 bytes and align it
17	17	* to CPU cache line size. Of course, the small table adds code inside
18		* CRC32 cycle, but cache misses overhead is bigger than overhead of
19		* the additional code. For example, ngx_crc32_short() of 16 byte message
	18	* CRC32 loop, but the cache misses overhead is bigger than overhead of
	19	* the additional code. For example, ngx_crc32_short() of 16 bytes of data
20	20	* takes half as much CPU clocks than ngx_crc32_long().
21	21	*/
22	22