Re: File copy system call proposal

From: Ton Hospel (
Date: Sat Dec 08 2001 - 18:11:13 EST

In article <>,
        Quinn Harris <> writes:
> I wasn't aware of the sendfile system call. But it apears that just
> like the mmap, write method suggested by H. Peter Anvin a memory copy is
> still performed when copying files from discs to duplicate the data for
> the buffer cache. This would undoubtedly be faster than repeatedly
> calling read and write as it avoids one mem copy. Yet GNU
> fileutils-4.1, that cp and install are part of, uses the read/write
> method. I expect this is primarily because of portability issues but I
> wouldn't think the use of mmap would cause portability issues.

It does in fact. On some systems locks and mmaps are mutually exclusive.
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This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:13 EST