Configure test for BG/P fails to identify need for _FILE_OFFSET_BITS.

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:24

The configure test on BG will result in the _LARGEFILE64_SOURCE macro being set but not the _FILE_OFFSET_BITS=64 macro. This results in off_t being defined as 32 bits instead of 64. This means the CP_MAX_BYTE_WRITTEN and CP_MAX_BYTE_READ can not be larger than 32 bits.

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:24

I think we need to leave the file_offset_bits undefined so that we can still support 32 bit applications that aren't promoting off_t. The 64 bit wrappers use explicit off64_t types so that we can handle both cases.

The main problem is probably just that we have used the wrong type in the CP_RECORD_READ and CP_RECORD_WRITE macros? I'll make a test case to confirm and work on a fix.

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:24

Confirmed MAX_BYTE_WRITTEN counter problem using the existing darshan-test/seek-test.c program (compiled with -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE).

Those macros use one variable local to the macro, and several variables stored in the runtime file record struct. The latter variables are all int64_t, while the former is an off_t. We can probably just change the local variable to an int64_t as well to fix the problem. Will confirm and test.

[shanedsnyder]

In GitLab by @shanedsnyder on Sep 24, 2015, 16:24

Fixed in r483.