Messages in this thread | | | Date | Mon, 2 Jul 2007 16:33:56 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: Concerning a post that you made about expandable anonymous shared mappings |
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On Fri, 29 Jun 2007, William Tambe wrote:
> I read a post that you made about not being able to expand anonymous shared > mapping with mremap(). And I am actually having that issue now.
I guess you're referring to the thread at http://lkml.org/lkml/2004/6/16/155 and you're asking either Stas or me.
> > You made the post in 2004 and we are now in 2007. I would like to know if that > feature was added because the code below always fail with bus error on my > machine. I use glibc 2.5
You've answered your own question: we did not make the change Stas suggested, IIRC because I remained a little uneasy with that change in behaviour, and nobody else spoke up for it.
I haven't given it any thought since then: do you have a good case for us to reconsider it?
Hugh
> > Thank you for helping. > > #define _GNU_SOURCE > #include <sys/mman.h> > #include <unistd.h> > > #include <stdio.h> > > main() { > void *ptr; > if ((ptr=mmap(0, 4096, PROT_READ|PROT_WRITE, > MAP_ANONYMOUS|MAP_SHARED|MAP_GROWSDOWN, 0, 0)) == -1) { > printf("failed to mmap\n"); > return; > } > > if ((ptr=mremap(ptr, 4096, 8192, MREMAP_MAYMOVE)) == -1) { > printf("failed to mremap\n"); > return; > } > > //why does this failed. I am well in the interval [4096, 8192] > *(unsigned int *)(ptr + 4096 + 8)= 10; > } - 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/
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