lib: Memory spike reduction for sh cmds at scale #16672
Merged
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The output buffer vty->obuf is a linked list where each element is of 4KB.
Currently, when a huge sh command like is executed on a large scale, all the vty_outs are processed and the entire data is accumulated.
After the entire vty execution, vtysh_flush proceeses and puts this data in the socket (131KB at a time).
Problem here is the memory spike for such heavy duty show commands.
The fix here is to chunkify the output on VTY shell by flushing it intermediately for every 128 KB of output accumulated and free the memory allocated for the buffer data.
This way, we achieve ~25-30% reduction in the memory spike.
Fixes: #16498
Note: This is a continuation of MR #16498