Alex Naidis a2f3d3c358 miatoll: Override readahead to 128KiB after post-boot
* Qualcomm decided to increase the read-ahead value to 512KiB [1].

 * This value resulted in frequent cases where read-ahead
   would be waiting for new I/O requests and thus ending
   up being synchronous rather than asynchronous.

 * As result, the main goal of Qualcomm's patch [1] which
   is to increase throughput ends up in a regression where
   read throughput is significantly lower than it ever
   would be with the recommended [2] read-ahead value.

 * This patch uses our existing loop in ramdisk to set
   the read-ahead value to 128KiB.

[1] https://source.codeaurora.org/quic/la/kernel/msm-4.19/commit/include/linux/mm.h?h=LA.UM.9.12.r1-09000-SMxx50.0&id=25d04e4ceb7c067907901842c223d62973d73a75
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/include/linux/mm.h?h=v4.19.160#n2397

Change-Id: I1980d904568fe4f1ce7b676452bcc44e4689f02f
Signed-off-by: Adithya R <gh0strider.2k18.reborn@gmail.com>
2021-04-23 07:15:21 +00:00
..