Re: 'disposable' dirty pages [was: Out Of Memory in v. 2.1]

Brandon S. Allbery KF8NH (allbery@kf8nh.apk.net)
Thu, 08 Oct 1998 17:52:04 -0300


In message <Pine.LNX.3.95.981008084640.1111A-100000@chaos.analogic.com>,
"Richa
rd B. Johnson" writes:
+-----
| On Thu, 8 Oct 1998, Cameron Simpson wrote:
| > On 7 Oct 1998, in message <Pine.GSO.3.96.981007120041.28599A-100000@ultra5>
| > Ely Wilson <plexus@ionet.net> wrote:
| > | Hmm, I'm wondering. I haev this application, it allocates 10 blocks each
| > | 1 megs in size. Then I free() 5 of those blocks, but the program is stil
| > | eating 10 megs of memory.
| > | Is this right?
| >
| > Well, it's "normal". UNIX processes generally only grow.
|
| glibc seems to give back memory. Here I allocate some memory, I don't
+--->8

That's why glibc uses mmap() for large pages. All it has to do when they're
freed is undo the mmap(), and the memory goes straight back to the OS.

-- 
brandon s. allbery	[os/2][linux][solaris][japh]	 allbery@kf8nh.apk.net
system administrator	     [WAY too many hats]	   allbery@ece.cmu.edu
electrical and computer engineering					 KF8NH
carnegie mellon university

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/