Re: Be more careful about updating refs

"Shawn O. Pearce" [off-list ref] wrote:

"Shawn O. Pearce" [off-list ref] wrote:

quoted

"Shawn O. Pearce" [off-list ref] wrote:

quoted

Junio C Hamano [off-list ref] wrote:

quoted

Especially, I am not sure if the issue only exists at the
end_packfile() boundary.  Don't we have the same issue reading
from the packfile being built, and isn't the only reason my hack
works it around is because access patterns of the testsuite
happens to not trigger it?

Yes, that's my take on it as well (see my other email).  The
testsuite must just be really lucky that its not hitting the
boundary condition.

I almost said gfi_unpack_entry() was immune from this bug, but
I went back and read the code again and determined that it does
in fact suffer from this under NO_MMAP, and we're just really
damn lucky nobody has caused it.

I think this solves the problem.  Its based on your first patch, but
would replace it.  The trick here is we close the cached windows if
we are accessing data from the packfile we are appending into and we
have increased the file length.  This way we don't blow away windows
during high read/low write periods, like during branch cache reloads.

Junio pointed out my first attempt at this didn't update the
memory pressure values, so we could "run out of memory" even
if we had plenty free.

Try #2...

OK, that was crap.  Don't even try it.

I'm holding off sending anything more until I get the test suite
to actually run without telling me the bus crashed into the wall.

-- 
Shawn.