evie/android_kernel_oneplus_msm8998
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ANDROID: mm: add config for default readahead size

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Change the 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, which greatly benefits to sequential
read throughput and thus boot performance.

Bug: 62413151
Test: boot walleye 100ms faster
Change-Id: Iad448cf1198056de46654dcb409466802b3b908d
Signed-off-by: Wei Wang <wvw@google.com>
This commit is contained in:
Wei Wang 2018-02-28 13:34:22 -08:00 • committed by codeworkx
parent 7cd83df04f
commit 4d467694ff
2 changed files with 9 additions and 1 deletions
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2
include/linux/mm.h
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@ -1989,7 +1989,7 @@ int write_one_page(struct page *page, int wait);
void task_dirty_inc(struct task_struct *tsk);
/* readahead.c */
#define VM_MAX_READAHEAD 512 /* kbytes */
#define VM_MAX_READAHEAD CONFIG_VM_MAX_READAHEAD /* kbytes */
#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */
int force_page_cache_readahead(struct address_space *mapping, struct file *filp,

8
mm/Kconfig
View file

@ -743,3 +743,11 @@ config PROCESS_RECLAIM
(addr, addr + size-bytes) of the process.
Any other vaule is ignored.
config VM_MAX_READAHEAD
int "default max readahead window size"
default 128
help
This sets the VM_MAX_READAHEAD value to allow the readahead window
to grow to a maximum size of configured. This will benefit sequential
read throughput and thus early boot performance.