git: ad2cca48ed53 - stable/13 - [fib algo][dxr] Optimize trie updating.

[Marko Zec]

The branch stable/13 has been updated by zec:

URL: https://cgit.FreeBSD.org/src/commit/?id=ad2cca48ed53e3282e9bc490074e75ccb50bffb9

commit ad2cca48ed53e3282e9bc490074e75ccb50bffb9
Author:     Marko Zec <zec at FreeBSD.org>
AuthorDate: 2021-09-15 20:36:59 +0000
Commit:     Marko Zec <zec at FreeBSD.org>
CommitDate: 2021-09-18 17:37:35 +0000

    [fib algo][dxr] Optimize trie updating.
    
    Don't rebuild in vain trie parts unaffected by accumulated incremental
    RIB updates.
    
    PR:             257965
    Tested by:      Konrad Kreciwilk
    MFC after:      3 days
    
    (cherry picked from commit b51f8bae570b4e908191a1dae9da38aacf8c0fab)
---
 sys/netinet/in_fib_dxr.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/in_fib_dxr.c b/sys/netinet/in_fib_dxr.c
index 7afe2a3da024..3c4e5700cd6c 100644
--- a/sys/netinet/in_fib_dxr.c
+++ b/sys/netinet/in_fib_dxr.c
@@ -915,7 +915,14 @@ dxr2_try_squeeze:
 
 	for (i = da->updates_low >> dxr_x; i <= da->updates_high >> dxr_x;
 	    i++) {
-		trie_unref(da, i);
+		if (!trie_rebuild) {
+			m = 0;
+			for (int j = 0; j < (1 << dxr_x); j += 32)
+				m |= da->updates_mask[((i << dxr_x) + j) >> 5];
+			if (m == 0)
+				continue;
+			trie_unref(da, i);
+		}
 		ti = trie_ref(da, i);
 		if (ti < 0)
 			return;