diff options
Diffstat (limited to 'src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c')
| -rw-r--r-- | src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c index dfa1d9e03b2..8db4b254366 100644 --- a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c +++ b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c @@ -106,14 +106,25 @@ extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t); */ uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t) { + static uint32_t (*crc32c_func)(const void *, size_t); #if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE) - unsigned long caps = getauxval(AT_HWCAP); + unsigned long caps; +#endif + + /* + * This function calls slow hardware functions; if the application doesn't realize that, they + * may call it on every request. + */ + if (crc32c_func != NULL) + return (crc32c_func); +#if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE) + caps = getauxval(AT_HWCAP); if (caps & HWCAP_S390_VX) - return (__wt_checksum_hw); + return (crc32c_func = __wt_checksum_hw); else - return (__wt_checksum_sw); + return (crc32c_func = __wt_checksum_sw); #else - return (__wt_checksum_sw); + return (crc32c_func = __wt_checksum_sw); #endif } |