Messages in this thread | | | Date | Mon, 06 Sep 2004 16:32:06 +0200 | From | Gunnar Ritter <> | Subject | Re: [PATCH 1/3] copyfile: generic_sendpage |
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Jörn Engel <joern@wohnheim.fh-wedel.de> wrote:
> On Mon, 6 September 2004 14:45:38 +0200, Gunnar Ritter wrote: > > It is an even more serious problem in my experience. I have been > > using sendfile() in my cp command at <http://heirloom.sourceforge.net> > > for quite some time, and I quickly decided to send files separated in > > some decently sized blocks. Otherwise if a whole file is sent at once > > and the source file is e.g. on an uncached floppy disk, cp will become > > uninterruptible for about a minute, which is a serious usability flaw. > > The user might discover that he is copying the wrong file, or he might > > simply change his mind and like to abort the copy or whatever. A > > performance gain of only 10 % is neglegible in comparison to this > > problem. Thus I think if copyfile() would not be interruptible by SIGINT > > and friends, its practical value would be quite limited. > > Using a loop of 4k sendfile commands should be easy enough to do.
Heck, guess what I did (although 4k seems a bit small).
> Problem is that copyfile(2) should do some decent cleanup after > receiving a signal. Hans Reiser got it right that all filesystem > operations should be atomic.
Then I don't see the point in having a copyfile system call. In fact, I would consider to deactivate it in every kernel derivative I'm responsible for to prevent hanging applications.
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