git: 42b3c16e3051 - main - fib_dxr: code hygiene, prune old code, no functional changes
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Date: Fri, 17 May 2024 17:05:29 UTC
The branch main has been updated by zec:
URL: https://cgit.FreeBSD.org/src/commit/?id=42b3c16e3051fdc04acc6276dd5d97dbe80ae7eb
commit 42b3c16e3051fdc04acc6276dd5d97dbe80ae7eb
Author: Marko Zec <zec@FreeBSD.org>
AuthorDate: 2024-05-17 16:57:25 +0000
Commit: Marko Zec <zec@FreeBSD.org>
CommitDate: 2024-05-17 16:57:25 +0000
fib_dxr: code hygiene, prune old code, no functional changes
The !DXR2 code corresponds to the original DXR encoding proposal from
2012 with a single direct-lookup stage, which is inferior to the more
recent (DXR2) variant with two-stage trie both in terms of memory
footprint of the lookup structures, and in terms of overall lookup
througput.
I'm axing the old code chunks to (hopefully) somewhat improve readability,
as well as to simplify future maintenance and updates.
MFC after: 1 week
---
sys/netinet/in_fib_dxr.c | 43 +------------------------------------------
1 file changed, 1 insertion(+), 42 deletions(-)
diff --git a/sys/netinet/in_fib_dxr.c b/sys/netinet/in_fib_dxr.c
index 326710cc4c45..b889131b544b 100644
--- a/sys/netinet/in_fib_dxr.c
+++ b/sys/netinet/in_fib_dxr.c
@@ -1,7 +1,7 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
- * Copyright (c) 2012-2022 Marko Zec
+ * Copyright (c) 2012-2024 Marko Zec
* Copyright (c) 2005, 2018 University of Zagreb
* Copyright (c) 2005 International Computer Science Institute
*
@@ -68,9 +68,6 @@
CTASSERT(DXR_TRIE_BITS >= 16 && DXR_TRIE_BITS <= 24);
-/* DXR2: two-stage primary trie, instead of a single direct lookup table */
-#define DXR2
-
#if DXR_TRIE_BITS > 16
#define DXR_D 16
#else
@@ -317,7 +314,6 @@ range_lookup(struct range_entry_long *rt, struct direct_entry de, uint32_t dst)
ntohl(key.addr4.s_addr))]); \
}
-#ifdef DXR2
#if DXR_TRIE_BITS > 16
DXR_LOOKUP_DEFINE(16)
#endif
@@ -328,23 +324,16 @@ DXR_LOOKUP_DEFINE(12)
DXR_LOOKUP_DEFINE(11)
DXR_LOOKUP_DEFINE(10)
DXR_LOOKUP_DEFINE(9)
-#endif /* DXR2 */
static int inline
dxr_lookup(struct dxr *dxr, uint32_t dst)
{
struct direct_entry de;
-#ifdef DXR2
uint16_t *dt = dxr->d;
struct direct_entry *xt = dxr->x;
de = xt[(dt[dst >> dxr->d_shift] << dxr->x_shift) +
((dst >> DXR_RANGE_SHIFT) & dxr->x_mask)];
-#else /* !DXR2 */
- struct direct_entry *dt = dxr->d;
-
- de = dt[dst >> DXR_RANGE_SHIFT];
-#endif /* !DXR2 */
if (__predict_true(de.fragments == FRAGS_MARK_HIT))
return (de.base);
return (range_lookup(dxr->r, de, dst));
@@ -571,7 +560,6 @@ chunk_unref(struct dxr_aux *da, uint32_t chunk)
LIST_INSERT_HEAD(&da->unused_chunks[i], cdp, cd_hash_le);
}
-#ifdef DXR2
static uint32_t
trie_hash(struct dxr_aux *da, uint32_t dxr_x, uint32_t index)
{
@@ -670,7 +658,6 @@ trie_unref(struct dxr_aux *da, uint32_t index)
}
} while (tp != NULL);
}
-#endif
static void
heap_inject(struct dxr_aux *da, uint32_t start, uint32_t end, uint32_t preflen,
@@ -864,12 +851,10 @@ dxr_build(struct dxr *dxr)
uint32_t r_size, dxr_tot_size;
uint32_t i, m, range_rebuild = 0;
uint32_t range_frag;
-#ifdef DXR2
struct trie_desc *tp;
uint32_t d_tbl_size, dxr_x, d_size, x_size;
uint32_t ti, trie_rebuild = 0, prev_size = 0;
uint32_t trie_frag;
-#endif
MPASS(dxr->d == NULL);
@@ -907,7 +892,6 @@ dxr_build(struct dxr *dxr)
}
range_rebuild = 1;
}
-#ifdef DXR2
if (da->x_tbl == NULL) {
da->x_tbl = malloc(sizeof(*da->x_tbl) * da->xtbl_size,
M_DXRAUX, M_NOWAIT);
@@ -918,7 +902,6 @@ dxr_build(struct dxr *dxr)
}
trie_rebuild = 1;
}
-#endif
microuptime(&t0);
@@ -970,7 +953,6 @@ range_build:
r_size = sizeof(*da->range_tbl) * da->rtbl_top;
microuptime(&t1);
-#ifdef DXR2
if (range_rebuild ||
abs(fls(da->prefixes) - fls(da->trie_rebuilt_prefixes)) > 1)
trie_rebuild = 1;
@@ -1044,10 +1026,6 @@ dxr2_try_squeeze:
goto dxr2_try_squeeze;
}
microuptime(&t2);
-#else /* !DXR2 */
- dxr_tot_size = sizeof(da->direct_tbl) + r_size;
- t2 = t1;
-#endif
dxr->d = malloc(dxr_tot_size, M_DXRLPM, M_NOWAIT);
if (dxr->d == NULL) {
@@ -1055,7 +1033,6 @@ dxr2_try_squeeze:
"Unable to allocate DXR lookup table");
return;
}
-#ifdef DXR2
memcpy(dxr->d, da->d_tbl, d_size);
dxr->x = ((char *) dxr->d) + d_size;
memcpy(dxr->x, da->x_tbl, x_size);
@@ -1063,10 +1040,6 @@ dxr2_try_squeeze:
dxr->d_shift = 32 - da->d_bits;
dxr->x_shift = dxr_x;
dxr->x_mask = 0xffffffffU >> (32 - dxr_x);
-#else /* !DXR2 */
- memcpy(dxr->d, da->direct_tbl, sizeof(da->direct_tbl));
- dxr->r = ((char *) dxr->d) + sizeof(da->direct_tbl);
-#endif
memcpy(dxr->r, da->range_tbl, r_size);
if (da->updates_low <= da->updates_high)
@@ -1076,36 +1049,24 @@ dxr2_try_squeeze:
da->updates_high = 0;
microuptime(&t3);
-#ifdef DXR2
FIB_PRINTF(LOG_INFO, da->fd, "D%dX%dR, %d prefixes, %d nhops (max)",
da->d_bits, dxr_x, rinfo.num_prefixes, rinfo.num_nhops);
-#else
- FIB_PRINTF(LOG_INFO, da->fd, "D%dR, %d prefixes, %d nhops (max)",
- DXR_D, rinfo.num_prefixes, rinfo.num_nhops);
-#endif
i = dxr_tot_size * 100;
if (rinfo.num_prefixes)
i /= rinfo.num_prefixes;
FIB_PRINTF(LOG_INFO, da->fd, "%d.%02d KBytes, %d.%02d Bytes/prefix",
dxr_tot_size / 1024, dxr_tot_size * 100 / 1024 % 100,
i / 100, i % 100);
-#ifdef DXR2
FIB_PRINTF(LOG_INFO, da->fd,
"%d.%02d%% trie, %d.%02d%% range fragmentation",
trie_frag / 100, trie_frag % 100,
range_frag / 100, range_frag % 100);
-#else
- FIB_PRINTF(LOG_INFO, da->fd, "%d.%01d%% range fragmentation",
- range_frag / 100, range_frag % 100);
-#endif
i = (t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec;
FIB_PRINTF(LOG_INFO, da->fd, "range table %s in %u.%03u ms",
range_rebuild ? "rebuilt" : "updated", i / 1000, i % 1000);
-#ifdef DXR2
i = (t2.tv_sec - t1.tv_sec) * 1000000 + t2.tv_usec - t1.tv_usec;
FIB_PRINTF(LOG_INFO, da->fd, "trie %s in %u.%03u ms",
trie_rebuild ? "rebuilt" : "updated", i / 1000, i % 1000);
-#endif
i = (t3.tv_sec - t2.tv_sec) * 1000000 + t3.tv_usec - t2.tv_usec;
FIB_PRINTF(LOG_INFO, da->fd, "snapshot forked in %u.%03u ms",
i / 1000, i % 1000);
@@ -1194,7 +1155,6 @@ static void *
choose_lookup_fn(struct dxr_aux *da)
{
-#ifdef DXR2
switch (da->d_bits) {
#if DXR_TRIE_BITS > 16
case 16:
@@ -1215,7 +1175,6 @@ choose_lookup_fn(struct dxr_aux *da)
case 9:
return (dxr_fib_lookup_9);
}
-#endif /* DXR2 */
return (dxr_fib_lookup);
}