Split seglist allocation heuristic from actual allocation

src/fellow_cache.c

@@ -2212,35 +2212,26 @@ fellow_busy_region_free(struct fellow_busy *fbo, struct buddy_off_extent *fdr)
 static uint16_t XXX_LIMIT_LDSEGS = 0;
 #endif
 
+static struct fellow_cache_res
+fellow_disk_seglist_alloc(struct fellow_busy *fbo,
+    struct fellow_cache_seglist *ofcsl, uint16_t ldsegs, uint8_t fht);
+
 static struct fellow_cache_res
 fellow_busy_body_seglist_alloc(struct fellow_busy *fbo,
     struct fellow_cache_seglist *ofcsl)
 {
-	struct fellow_disk_seglist *ofdsl, *fdsl;
-	struct fellow_cache_seglist *fcsl;
 	struct fellow_cache *fc;
-	struct buddy_off_extent *fdr;
-	struct buddy_ptr_extent fdsl_mem, fcsl_mem;
-	struct buddy_reqs *reqs;
-	unsigned chunk_exponent, u;
+	unsigned chunk_exponent;
 	uint16_t ldsegs;
 	size_t sz;
 
 	CHECK_OBJ_NOTNULL(fbo, FELLOW_BUSY_MAGIC);
 
-	CHECK_OBJ_NOTNULL(ofcsl, FELLOW_CACHE_SEGLIST_MAGIC);
-	AZ(ofcsl->next);
-
-	ofdsl = ofcsl->fdsl;
-	AZ(ofdsl->next.off);
-	AZ(ofdsl->next.size);
-
 	fc = fbo->fc;
 	CHECK_OBJ_NOTNULL(fc, FELLOW_CACHE_MAGIC);
 	CHECK_OBJ_NOTNULL(fc->tune, STVFE_TUNE_MAGIC);
 	chunk_exponent = fc->tune->chunk_exponent;
 
-
 	assert(fbo->sz_estimate > fbo->sz_returned);
 
 	if (fbo->grown) {
@@ -2259,6 +2250,32 @@ fellow_busy_body_seglist_alloc(struct fellow_busy *fbo,
 		ldsegs = XXX_LIMIT_LDSEGS;
 #endif
 
+	return (
+	    fellow_disk_seglist_alloc(fbo, ofcsl,
+	      ldsegs, fc->tune->hash_obj));
+}
+
+static struct fellow_cache_res
+fellow_disk_seglist_alloc(struct fellow_busy *fbo,
+    struct fellow_cache_seglist *ofcsl, uint16_t ldsegs, uint8_t fht)
+{
+	struct fellow_cache_seglist *fcsl;
+	struct fellow_disk_seglist *ofdsl, *fdsl;
+	struct buddy_off_extent *fdr;
+	struct buddy_ptr_extent fdsl_mem, fcsl_mem;
+	struct buddy_reqs *reqs;
+	unsigned u;
+	size_t sz;
+
+	CHECK_OBJ_NOTNULL(fbo, FELLOW_BUSY_MAGIC);
+
+	CHECK_OBJ_NOTNULL(ofcsl, FELLOW_CACHE_SEGLIST_MAGIC);
+	AZ(ofcsl->next);
+
+	ofdsl = ofcsl->fdsl;
+	AZ(ofdsl->next.off);
+	AZ(ofdsl->next.size);
+
 	sz = fellow_disk_seglist_size(fdsl, ldsegs);
 
 	fdr = fellow_busy_region_alloc(fbo, sz, 0);
@@ -2293,7 +2310,7 @@ fellow_busy_body_seglist_alloc(struct fellow_busy *fbo,
 	fdsl = fdsl_mem.ptr;
 	AN(fdsl);
 	assert(fdsl_mem.size == fdr->size);
-	fellow_disk_seglist_init(fdsl, ldsegs, fc->tune->hash_obj);
+	fellow_disk_seglist_init(fdsl, ldsegs, fht);
 
 	fcsl = fcsl_mem.ptr;
 	AN(fcsl);