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dc.contributor.advisorGopinath, Kanchi
dc.contributor.authorDubey, Abhishek
dc.date.accessioned2020-06-04T06:51:28Z
dc.date.available2020-06-04T06:51:28Z
dc.date.submitted2020
dc.identifier.urihttp://etd.iisc.ac.in/handle/2005/4433
dc.description.abstractDeferred freeing is the fundamental technique used in Read-Copy-Update (RCU) synchronization technique where reclamation of resources is deferred until the completion of all active RCU read-side critical sections. We observe that faults inside an RCU read-side critical section can indefinitely block writers that are waiting for the completion of RCU readers and also lead to system failures by preventing the reclamation of deferred resources. We show that the impact of such faults in the Linux kernel is global; a fault in one subsystem can propagate and exhaust critical resources in other unrelated subsystems opening a window of opportunity for DoS-based attacks. For example, a fault in a filesystem can exhaust the process ulimit resulting in fork failures. Since, guaranteeing the absence of faults is practically impossible, it is imperative to harden RCU to tolerate faults. We first study the impact of mitigating lockup by termination of the faulty thread, as thread termination is standard approach used by Linux as recovery strategy. Whereas, another solution is stack based and do not require termination of faulty thread. We demonstrate the impact of faults in RCU read-side critical sections and present RCU recovery techniques that use novel approaches to detect and isolate effect of such faults. We also discuss system consistency once the fault is handled by our approaches. Timely recovery results in a usable system, preserving the user application state and increasing the system’s availability. Our evaluation in the Linux kernel shows that our solution can prevent resource exhaustion in the presence of faults with no additional overhead in the absence of faults.en_US
dc.language.isoen_USen_US
dc.rightsI grant Indian Institute of Science the right to archive and to make available my thesis or dissertation in whole or in part in all forms of media, now hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertationen_US
dc.subjectRCUen_US
dc.subjectOSen_US
dc.subjectOperating Systemen_US
dc.subjectLinuxen_US
dc.subject.classificationResearch Subject Categories::TECHNOLOGY::Information technology::Computer science::Computer scienceen_US
dc.titleFA RCU: Fault Aware Read-Copy-Updateen_US
dc.typeThesisen_US
dc.degree.nameMTech(Res)en_US
dc.degree.levelMastersen_US
dc.degree.grantorIndian Institute of Scienceen_US
dc.degree.disciplineEngineeringen_US


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