Callers already verify that they are calling ashmem API on a valid fd by
calling ashmem_valid first. Lets make the fstat syscall only if the
ioctl returns -ENOTTY. This means in the regular case, only 1 syscall is
needed (ioctl) vs the current 2 (fstat+ioctl).
Some data to show improvements in reduction of vfs_getattr calls in the
kernel by 10x when doing a camera.
Test: Boot and camera CTS
Bug: 111418894
Change-Id: I992620bbe44355e54ba19eeac81da586c5e5a6e0
Signed-off-by: Joel Fernandes <joelaf@google.com>
Just the minimial changes to get this to actually build, because otherwise
we always bog down trying to rewrite everything (when the real answer
is usually "stop using libcutils, it's awful").
This doesn't move a handful of files: two are basically just BSD libc
source, a couple have outstanding code reviews, and one can be deleted
(but I'll do that in a separate change).
I'm also skipping the presubmit hooks because otherwise clang-format
wants to reformat everything. I'll follow up with that...
Bug: N/A
Test: builds
Change-Id: I06403f465b67c8e493bad466dd76b1151eed5993
