Application-friendly kernel interfaces [LWN.net]

Application-friendly kernel interfaces

Posted Mar 29, 2007 3:07 UTC (Thu) by jreiser (subscriber, #11027)
Parent article: Application-friendly kernel interfaces

It's not possible to do normal reads and writes from this filesystem [hugetlbfs] ...

and that makes hugetlbfs less than a filesystem. Hugetlbfs is a hack, and it is hard to use. Hugetlbfs is so hard to use that our editor could not find an actual working example to cite. Show me the code!

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Application-friendly kernel interfaces

Posted Mar 29, 2007 6:02 UTC (Thu) by ebiederm (subscriber, #35028) [Link]

Huh?

#define PATH_TO_HUGETLBFS "/dev/hshm"

void *map_anon_hugetlb(size_t size)
{
char buffer[PATH_MAX];
int fd;
snprintf(buffer, "%s/XXXXXX", PATH_TO_HUGETLBFS);
fd = mkstemp(buffer);
if (fd < 0)
return MAP_FAILED;
unlink(buffer);
ftruncate(fd, size);
return mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
}

Application-friendly kernel interfaces

Posted Mar 29, 2007 15:16 UTC (Thu) by vmole (guest, #111) [Link]

snprintf(buffer, "%s/XXXXXX", PATH_TO_HUGETLBFS);

So much for working code... ;-)

Application-friendly kernel interfaces

Posted Mar 29, 2007 15:38 UTC (Thu) by ebiederm (subscriber, #35028) [Link]

Yea yea.

snprintf(buffer, sizoef(buffer), ....);

Application-friendly kernel interfaces

Posted Mar 29, 2007 16:02 UTC (Thu) by vmole (guest, #111) [Link]

Strike 2! [Steve readies for the next pitch.]

Yeah yeah, I know that code written for forums like this is at best psuedo-code. Hell, I blew it just the other day, so I'm hardly the one to be picking on you, but I was amused by the "Show me the code" - "huh?" sequence.

Perhaps we can get away with claiming "Well, it was a actually a debugging test for the reader". Right, that's it.