The explanation of the error message is as follows:
%SYS-2-MALLOCFAIL: Memory allocation of [X] bytes failed from
0x6015EC84, pool [Pool], alignment 0 -Process=
"[Process]" ipl= 6, pid=5
[X] = the number of bytes the router tried to allocate, but could not find enough free memory to do so
[Pool] indicates whether the processor memory ('Pool Processor') or the packet memory ('pool I/O') is affected. High end routers (7000, 7500 series) have their buffers in main dynamic random-access memory (DRAM), so a lack of packet memory will be reported as "pool processor". 7200 series and Versatile Interface Processor (VIP) cards may also report errors in pool Protocol Control Information ('pool PCI')" for the packet memory.
[Process] is the process that was affected by the lack of memory.