README VERSION : 1.1 README CREATION DATE : 2014-07-10 PATCH-ID : VRTSllt-6.1.1.000 PATCH NAME : VRTSllt 6.1.1.000 BASE PACKAGE NAME : VRTSllt BASE PACKAGE VERSION : 6.1.0.000 SUPERSEDED PATCHES : NONE REQUIRED PATCHES : NONE INCOMPATIBLE PATCHES : NONE SUPPORTED PADV : rhel6_x86_64 (P-PLATFORM , A-ARCHITECTURE , D-DISTRIBUTION , V-VERSION) PATCH CATEGORY : PANIC PATCH CRITICALITY : CRITICAL HAS KERNEL COMPONENT : YES ID : NONE REBOOT REQUIRED : NO REQUIRE APPLICATION DOWNTIME : YES PATCH INSTALLATION INSTRUCTIONS: -------------------------------- Please refer to Install Guide for install instructions and Release Notes for other information. PATCH UNINSTALLATION INSTRUCTIONS: ---------------------------------- Please refer to Install Guide for uninstall instructions and Release Notes for other information. SPECIAL INSTRUCTIONS: ----------------------------- NONE SUMMARY OF FIXED ISSUES: ----------------------------------------- PATCH ID:VRTSllt-6.1.1.000 3376505 (3410309) The LLT driver fails to load and logs a message in the syslog. 3458677 (3460985) The system panics and logs an error message in the syslog. SUMMARY OF KNOWN ISSUES: ----------------------------------------- NONE KNOWN ISSUES : -------------- NONE FIXED INCIDENTS: ---------------- PATCH ID:VRTSllt-6.1.1.000 * INCIDENT NO:3376505 TRACKING ID:3410309 SYMPTOM: The Low Latency Transport (LLT) driver fails to load and logs the following message in the syslog when a mismatch is observed in the RDMA-specific symbols. llt: disagrees about version of symbol rdma_connect llt: Unknown symbol rdma_connect llt: disagrees about version of symbol rdma_destroy_id llt: Unknown symbol rdma_destroy_id DESCRIPTION: The LLT driver fails to load when an external Open Fabrics Enterprise Distribution (OFED) (OFA or MLNX_OFED) stack is installed on a system. The OFED replaces the native RDMA-related drivers (shipped with the OS) with the external OFED drivers. Since LLT is built against the native RDMA drivers, LLT fails due to a symbol mismatch when the startup script tries to load LLT. RESOLUTION: The code is modified in the LLT startup script to detect if any external OFED is installed on the system. If the script detects an external OFED, then it loads an LLT driver (without the RDMA symbols) of a non-RDMA version. Since this LLT does not contain RDMA-specific symbols, the LLT driver successfully loads. However, the LLT driver does not have the RDMA functionality. In this case, LLT can be used either in Ethernet or in a UDP mode. * INCIDENT NO:3458677 TRACKING ID:3460985 SYMPTOM: The system panics and logs the following error message in the syslog: kernel:BUG: soft lockup - CPU#8 stuck for 67s! [llt_rfreem:7125] DESCRIPTION: With the LLT-RDMA feature, Low Latency Transport (LLT) threads can be busy for a longer period of time without scheduling out of CPU depending on workload. The Linux kernel may falsely detect this activity as an unresponsive task or a soft lockup, thus causing the panic. This issue is observed in the LLT threads, such as lltd, llt_rdlv and llt_rfreem. RESOLUTION: The code is modified in order to avoid false alarms for soft lockups. The LLT threads now schedule themselves out of the CPU after the specified time, which is configured by default based on the watchdog_threshold/softlockup_threshold value in the system configuration. The default value can be changed using the lltconfig utility (lltconfig -T yieldthresh:value). This value decides when the LLT threads schedule themselves out. INCIDENTS FROM OLD PATCHES: --------------------------- NONE