RCU
A synchronization mechanism in the Linux kernel known for zero overhead on the read side. Read operations take no locks; write operations create a new copy and defer reclamation of the old data until all readers have left the critical section before freeing it.
Timeline (last 90 days)
In provisioned mode, 1 RCU represents one strongly consistent read per second of a 4 KB item, or two eventually consistent reads per second; 1 WCU represents 1 KB written per second; when an item exceeds the threshold it rounds up and consumes multiple units.
The new approach bypasses reference counting with the RCU mechanism, folios leaving the cache are returned to the page allocator only after a grace period, and readers can copy data directly from the page without touching the reference count.
Two of the eight patches add safety valves: when a CPU queues more than 1024 pages, an accelerated grace period is forcibly triggered.
All Facts (3)
In provisioned mode, 1 RCU represents one strongly consistent read per second of a 4 KB item, or two eventually consistent reads per second; 1 WCU represents 1 KB written per second; when an item exceeds the threshold it rounds up and consumes multiple units.
50%UnverifiedThe new approach bypasses reference counting with the RCU mechanism, folios leaving the cache are returned to the page allocator only after a grace period, and readers can copy data directly from the page without touching the reference count.
50%UnverifiedTwo of the eight patches add safety valves: when a CPU queues more than 1024 pages, an accelerated grace period is forcibly triggered.
50%