From 8c7f01025f7becd577bed9af93f974fc6798c5a3 Mon Sep 17 00:00:00 2001 From: "karam.lee" Date: Fri, 12 Dec 2014 16:56:53 -0800 Subject: [PATCH] zram: implement rw_page operation of zram This patch implements rw_page operation for zram block device. I implemented the feature in zram and tested it. Test bed was the G2, LG electronic mobile device, whtich has msm8974 processor and 2GB memory. With a memory allocation test program consuming memory, the system generates swap. Operating time of swap_write_page() was measured. -------------------------------------------------- | | operating time | improvement | | | (20 runs average) | | -------------------------------------------------- |with patch | 1061.15 us | +2.4% | -------------------------------------------------- |without patch| 1087.35 us | | -------------------------------------------------- Each test(with paged_io,with BIO) result set shows normal distribution and has equal variance. I mean the two values are valid result to compare. I can say operation with paged I/O(without BIO) is faster 2.4% with confidence level 95%. [minchan@kernel.org: make rw_page opeartion return 0] [minchan@kernel.org: rely on the bi_end_io for zram_rw_page fails] [sergey.senozhatsky@gmail.com: code cleanup] [minchan@kernel.org: add comment] Signed-off-by: karam.lee Acked-by: Minchan Kim Acked-by: Jerome Marchand Cc: Matthew Wilcox Cc: Nitin Gupta Cc: Signed-off-by: Minchan Kim Signed-off-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed