Re: [PATCH 4/5] Add lock_page_killable

From: Andrew Morton
Date: Thu Oct 25 2007 - 00:11:54 EST


On Wed, 24 Oct 2007 08:24:57 -0400 Matthew Wilcox <matthew@xxxxxx> wrote:

> and associated infrastructure such as sync_page_killable and
> fatal_signal_pending. Use lock_page_killable in do_generic_mapping_read()
> to allow us to kill `cat' of a file on an NFS-mounted filesystem.

whoa, big change.

What exactly are the semantics here? If the process has actually been
killed (ie: we know that userspace won't be running again) then we break
out of a lock_page() and allow the process to exit? ie: it's basically
invisible to userspace?

If so, it sounds OK. I guess. We're still screwed if the process is doing
a synchronous write and lots of other scenarios.

How well has this been tested?

Have the NFS guys had a think about it?

Why does it return -EIO from read() and not -EINTR?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/