Messages in this thread | | | Date | Thu, 10 Oct 2002 13:50:43 -0400 | From | Mark Mielke <> | Subject | Re: [PATCH] O_STREAMING - flag for optimal streaming I/O |
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On Thu, Oct 10, 2002 at 12:55:08PM +0200, Helge Hafting wrote: > Mark Mielke wrote: > > I might be wrong, but it seems to me that O_STREAMING isn't the answer > > to everything. The primary benefactors of O_STREAMING would be > > applications that read very large files that do not fit into RAM, from > > start to finish. > It don't have to be a file that don't fit into RAM. Remember, other > running apps wants memory and cache too, so the "fair share" of memory > for _this_ process is much smaller than all of RAM. > So, O_STREAMING makes sense for all files where we know that we're going > sequentially and that caching this for long won't help. > (Because the contents likely will be pushed out before we need > them again anyway (DVD case) or we know were going to delete > the file, or we simply don't want to push anything else > out even if we could cache this.)
Then perhaps O_STREAMING should be called O_EXTENDEDSTREAMING.
If you overload O_STREAMING to contain all possibile uses for sequential reads, you end up hurting yourself.
Small files are different beasts from large files. If you want O_STREAMING to work in all cases, you really want standard mode to work in all cases, and O_STREAMING is not for you.
mark
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