From: Wei Wang <wvw@xxxxxxxxxx> Change VM_MAX_READAHEAD value from the default 128KB to a configurable value. This will allow the readahead window to grow to a maximum size bigger than 128KB during boot, which could benefit to sequential read throughput and thus boot performance. Signed-off-by: Wei Wang <wvw@xxxxxxxxxx> --- include/linux/mm.h | 2 +- mm/Kconfig | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index ad06d42adb1a..d7dc6125833e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2291,7 +2291,7 @@ int __must_check write_one_page(struct page *page); void task_dirty_inc(struct task_struct *tsk); /* readahead.c */ -#define VM_MAX_READAHEAD 128 /* kbytes */ +#define VM_MAX_READAHEAD CONFIG_VM_MAX_READAHEAD_KB #define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */ int force_page_cache_readahead(struct address_space *mapping, struct file *filp, diff --git a/mm/Kconfig b/mm/Kconfig index c782e8fb7235..da9ff543bdb9 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -760,3 +760,11 @@ config GUP_BENCHMARK performance of get_user_pages_fast(). See tools/testing/selftests/vm/gup_benchmark.c + +config VM_MAX_READAHEAD_KB + int "Default max readahead window size in Kilobytes" + default 128 + help + This sets the VM_MAX_READAHEAD value to allow the readahead window + to grow to a maximum size of configured. Increasing this value will + benefit sequential read throughput. -- 2.16.2.804.g6dcf76e118-goog
