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author | mav <mav@FreeBSD.org> | 2008-02-01 11:01:15 +0000 |
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committer | mav <mav@FreeBSD.org> | 2008-02-01 11:01:15 +0000 |
commit | 49092fb3fc0e8e52a381c2a4d5f8fddf6e5b1b1e (patch) | |
tree | 046b65347477fa717b0dd934ff88f5aafb0ef814 | |
parent | 7e0b4128cbb5e697e9bb8b7926e9129aeea3c4e2 (diff) | |
download | FreeBSD-src-49092fb3fc0e8e52a381c2a4d5f8fddf6e5b1b1e.zip FreeBSD-src-49092fb3fc0e8e52a381c2a4d5f8fddf6e5b1b1e.tar.gz |
Add comments about stack protection mechanism.
-rw-r--r-- | sys/netgraph/ng_base.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sys/netgraph/ng_base.c b/sys/netgraph/ng_base.c index 2bf6508..8bb4382 100644 --- a/sys/netgraph/ng_base.c +++ b/sys/netgraph/ng_base.c @@ -2372,6 +2372,14 @@ ng_snd_item(item_p item, int flags) } #ifdef GET_STACK_USAGE else { + /* + * Most of netgraph nodes has small stack consumption and + * for them it is more then enogh 20% of free stack. + * Nodes/hooks with higher stack usage should be marked as + * HI_STACK. For them 50% of stack will be guarantied. + * XXX: Values 50% (64/128) and 80% (100/128) are completely + * empirical. + */ size_t st, su; GET_STACK_USAGE(st, su); su = (su * 128) / st; |