Messages in this thread | | | Date | Tue, 8 Oct 2002 22:34:34 +0200 | From | Matthias Schniedermeyer <> | Subject | Re: [PATCH] O_STREAMING - flag for optimal streaming I/O |
| |
On Tue, Oct 08, 2002 at 01:03:11PM -0700, Andrew Morton wrote: > Matthias Schniedermeyer wrote: > > > > ... > > I only have 3 GB of RAM, and creating and writing trashes the whole > > cache twice. > > That's actually something completely dumb and irritating which > Linux has done for ever ;) > > What we need is to detect the situation where someone is linearly > walking through a file which is preposterously too large to cache, > and just start dropping it. > > It's not hard to implement the lower machinery to do that - it would > basically be an internal call to posix_fadvise(), which we don't > have but could and perhaps should... > > The tricky part is designing the algorithm which decides when to > pull the trigger.
I have more of this cases.
I use a program called VDR. This is for recording digital-TV-program from satallite.
After a recording is finished i cut the recordings. I my case i "stream" the input-data via NFS from the recording machine(s) through a converter into the local temporary directory. After i have enough files i create ISO-images of the files. When i create an ISO-images i "stream" the files from HDD1 to HDD2 because otherwise it would completly kill the performance. Then i burn the ISO-Image onto a DVD-R.
Every single part in the whole process trashes the cache.
Bis denn
-- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |