Searched hist:10325 (Results 1 - 1 of 1) sorted by relevance
| /gem5/src/mem/ | ||
| H A D | packet.cc | 10325:7aacec2a247d Wed Sep 03 07:42:00 EDT 2014 Geoffrey Blake <geoffrey.blake@arm.com> cache: Fix handling of LL/SC requests under contention If a set of LL/SC requests contend on the same cache block we can get into a situation where CPUs will deadlock if they expect a failed SC to supply them data. This case happens where 3 or more cores are contending for a cache block using LL/SC and the system is configured where 2 cores are connected to a local bus and the third is connected to a remote bus. If a core on the local bus sends an SCUpgrade and the core on the remote bus sends and SCUpgrade they will race to see who will win the SC access. In the meantime if the other core appends a read to one of the SCUpgrades it will expect to be supplied data by that SCUpgrade transaction. If it happens that the SCUpgrade that was picked to supply the data is failed, it will drop the appended request for data and never respond, leaving the requesting core to deadlock. This patch makes all SC's behave as normal stores to prevent this case but still makes sure to check whether it can perform the update. |
Completed in 23 milliseconds