commit c55e633f7446fea7b73be75f6713fad6493edf05 Author: David Goulet dgoulet@torproject.org Date: Mon Jun 22 15:28:47 2020 -0400

kist: Document a magic value in channel_should_write_to_kernel()

Closes #40008

Signed-off-by: David Goulet dgoulet@torproject.org --- src/core/or/scheduler_kist.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/src/core/or/scheduler_kist.c b/src/core/or/scheduler_kist.c index c73d768f8..5c1922847 100644 --- a/src/core/or/scheduler_kist.c +++ b/src/core/or/scheduler_kist.c @@ -445,6 +445,11 @@ update_socket_written(socket_table_t *table, channel_t *chan, size_t bytes) * one cell for each and bouncing back and forth. This KIST impl avoids that * by only writing a channel's outbuf to the kernel if it has 8 cells or more * in it. + * + * Note: The number 8 has been picked for no particular reasons except that it + * is 4096 bytes which is a common number for buffering. A TLS record can hold + * up to 16KiB thus using 8 cells means that a relay will at most send a TLS + * record of 4KiB or 1/4 of the maximum capacity of a TLS record. */ MOCK_IMPL(int, channel_should_write_to_kernel, (outbuf_table_t *table, channel_t *chan))