Messages in this thread | | | From | Mike Harrold <> | Subject | Re: Is swap == 2 * RAM a permanent thing? | Date | Thu, 15 Mar 2001 09:24:28 -0500 (EST) |
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> The reason is that the Linux 2.4 kernel no longer reclaims swap > space on swapin (2.2 reclaimed swap space on write access, which > lead to fragmented swap space in lots of workloads). > > This means that a lot of memory ends up "duplicated" in RAM and > in swap. > > I plan on doing some code to reclaim swap space when we run out, > but Linus doesn't seem to like that idea very much. His argument > (when you're OOM, you should just fail instead of limp along) > makes a lot of sense, however, and the reclaiming of swap space > isn't really high on my TODO list ... > > OTOH, for people who have swap < RAM and use it just as a small > overflow area, Linus' argument falls short, so I guess some time > in the future we will have code to reclaim swap space when needed.
I have some questions on this.
1) If a process uses swap space and then later (after being paged into memory -- or even not) it completes, is killed, etc., is the swap space reclaimed then?
2) If a process uses swap, is paged into memory, and is then swapped out again, does it re-use the same swap as before?
If the answer to either question is no, then IMHO, that's a pretty serious design flaw.
Regards,
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