On Thu, Oct 22, 2020 at 12:39:14AM +0100, Al Viro wrote:
On Wed, Oct 21, 2020 at 06:13:01PM +0200, Greg KH wrote:
quoted
On Fri, Sep 25, 2020 at 06:51:39AM +0200, Christoph Hellwig wrote:
quoted
From: David Laight <redacted>
This lets the compiler inline it into import_iovec() generating
much better code.
Signed-off-by: David Laight <redacted>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 179 ------------------------------------------------
lib/iov_iter.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 176 insertions(+), 179 deletions(-)
Strangely, this commit causes a regression in Linus's tree right now.
I can't really figure out what the regression is, only that this commit
triggers a "large Android system binary" from working properly. There's
no kernel log messages anywhere, and I don't have any way to strace the
thing in the testing framework, so any hints that people can provide
would be most appreciated.
It's a pure move - modulo changed line breaks in the argument lists
the functions involved are identical before and after that (just checked
that directly, by checking out the trees before and after, extracting two
functions in question from fs/read_write.c and lib/iov_iter.c (before and
after, resp.) and checking the diff between those.
How certain is your bisection?
The bisection is very reproducable.
But, this looks now to be a compiler bug. I'm using the latest version
of clang and if I put "noinline" at the front of the function,
everything works.
Nick, any ideas here as to who I should report this to?
I'll work on a fixup patch for the Android kernel tree to see if I can
work around it there, but others will hit this in Linus's tree sooner or
later...
thanks,
greg k-h