[EMAIL PROTECTED] wrote on Tue, 25 Jul 2006 15:20 -0400:
> /*
> + * Hopefully we don't need to define O_DIRECT on special machines (?)
> + *
> +#if defined(__linux__)
> +#include <asm/page.h>
> +# if !defined(O_DIRECT) && (defined(__alpha__) || defined(__i386__))
> +# define O_DIRECT 040000
> +# endif
> +#endif
[..]
> #define PREAD pread64
> -#define PWRITE pwrite64
> +#define PWRITE pwrite64
> +*/
> +
> +#define PREAD pread
> +#define PWRITE pwrite
I would prefer to see this handled by the configure script, if
possible. No O_DIRECT in fcntl.h => no support in pvfs2; we
shouldn't get in the business of defining these constants if
possible to avoid it.
> + /*
> + * use tmp buffer in case data is not aligned to pagesize and
> + * do a read modify write for writes or read more data than
> + * necessary (for reads).
> + * Problem: files have to be a size * 512 resp. mem_pagesize.
> + */
Where is 512 enforced? How do you know it is exactly 512? Do all
FSes support O_DIRECT at a 512-byte granularity? How can you detect
this at runtime?
> + bzero( odirectbuf + end_offset, physical_startPos +
> end_offset );
Use memset. bzero is deprecated, non-posix.
> + buff_real = (unsigned char *)(((unsigned long)odirectBuffAlloc +
> + mem_pagesize - 1) & (~(mem_pagesize - 1)));
Use uintptr_t for this sort of calculation. ulong is not guaranteed
to hold a pointer.
Great to see you've gotten O_DIRECT to work!
-- Pete
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