hi again Apple Experts..I was just reading a PDF document, no more, and the problem appeared again... again my logs...
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x1760f4 on MAIN ring: called from
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x1760f2
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0ed58, wrap count = 1742
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x0000f320
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x1760f2
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x1760f2
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f401 still waiting
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x176104 on MAIN ring: called from
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x1760f3
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0eda8, wrap count = 1742
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x0000f320
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x1760f3
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x1760f3
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:14 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x176110 on MAIN ring: called from
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x1760fc
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0f140, wrap count = 1742
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x000009d0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x1760fc
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x1760fc
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x1760fe
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0f1c8, wrap count = 1742
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x000009d0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x1760fe
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x1760fe
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:19 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x176105
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0f3f4, wrap count = 1742
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x000009d0
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x176105
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x176105
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:24 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x17610f
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0f718, wrap count = 1742
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x00000e10
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x17610f
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x17610f
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:29 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x176116
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0fa2c, wrap count = 1742
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x00000e10
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x176116
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x176116
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:34 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x176118
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0fab8, wrap count = 1742
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x00000e10
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x176118
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x176118
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:39 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x17611a
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0fb40, wrap count = 1742
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x00000e10
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x17611a
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x17611a
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: trying to clear semaphore wait on MAIN ring
Aug 28 01:26:44 MacBook-Pro-de-Andres-2 kernel[0]: After attempt to clear semaphore wait = 0x0000f001 no longer waiting
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: stampWait: Overflowed checking for stamp 0x17614f on MAIN ring: called from
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: timestamp = 0x17611c
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in MAIN graphics engine ****
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xd9c0fbc8, wrap count = 1742
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x00000e10
Aug 28 01:26:49 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f401 enabled, auto report disabled, not waiting, semaphore is waiting, length = 0x010 4KB pages
ONE MORE TIME REBOOTING MY MBP...
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: **** Debug info for *possible* hang in BLT graphics engine ****
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: ring head = 0xbea0a788, wrap count = 1525
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: ring tail = 0x0000f020
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: ring control = 0x0000f001 enabled, auto report disabled, not waiting, semaphore not waiting, length = 0x010 4KB pages
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: timestamps = 0x64875
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: Semaphore register values:
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: VRSYNC: (0x12044) = 0x17612a
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: BRSYNC: (0x22040) = 0x1
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: RVSYNC: (0x 2040) = 0x0
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: BVSYNC: (0x22044) = 0x0
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: RBSYNC: (0x 2044) = 0x0
Aug 28 01:28:34 MacBook-Pro-de-Andres-2 kernel[0]: VBSYNC: (0x12040) = 0x0
Aug 28 01:29:21 localhost bootlog[0]: BOOT_TIME 1346135361 0
Aug 28 01:29:48 localhost kernel[0]: PMAP: PCID enabled
Aug 28 01:29:48 localhost kernel[0]: Darwin Kernel Version 12.1.0: Tue Aug 14 13:29:55 PDT 2012; root:xnu-2050.9.2~1/RELEASE_X86_64
maybe, Have you identified this problem?..this happens randomly, at this time I have not a kind of pattern in order to understand this behavior...If you need more information about my MB I could post it again.