ASUSwrt dnsmasq addn-hosts entry limit

[pseu_asus]

Hi, Seems on my ASUSwrt, the dnsmasq addn-hosts entries are limited.
I have the following config on the dnsmasq user conf file:

addn-hosts=/jffs/hosts.

Then I download multiple ad-block and malware-block hosts file from Internet and put to the directory /jffs/hosts. The total entries in multiple files are nearly 1.2M. There are 37 txt files in it.

The DNSMASQ picks up it but seems it exceeds the limit, here is the dnsmasq log output:

Oct 24 16:39:21 dnsmasq[27166]: started, version 2.84 cachesize 1500
Oct 24 16:39:21 dnsmasq[27166]: compile time options: IPv6 GNU-getopt no-RTC no-DBus no-UBus no-i18n no-IDN DHCP DHCPv6 no-Lua no-TFTP no-conntrack ipset no-auth no-cryptohash no-DNSSEC no-ID no-loop-detect no-inotify no-dumpfile
Oct 24 16:39:21 dnsmasq[27166]: warning: interface br2 does not currently exist
Oct 24 16:39:21 dnsmasq[27166]: warning: interface br1 does not currently exist
Oct 24 16:39:21 dnsmasq[27166]: warning: interface pptp* does not currently exist
Oct 24 16:39:21 dnsmasq-dhcp[27166]: DHCP, IP range 10.10.10.50 -- 10.10.10.199, lease time 4h
Oct 24 16:39:21 dnsmasq[27166]: read /etc/hosts - 6 addresses
Oct 24 16:39:21 dnsmasq[27166]: read /tmp/hosts/2Step_amazon_disconnectme_simple_malvertising.txt - 2736 addresses
Oct 24 16:39:21 dnsmasq[27166]: read /tmp/hosts/2Step_amazon_disconnectme_simplead.txt - 2701 addresses
Oct 24 16:39:21 dnsmasq[27166]: read /tmp/hosts/2Step_bitbucket_Mandiant_APT1_Report_AppendixD.txt - 2046 addresses
Oct 24 16:39:21 dnsmasq[27166]: read /tmp/hosts/2Step_digitalside_threat_intel.txt - 58 addresses
Oct 24 16:39:23 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_RPiList-Malware.txt - 180217 addresses
Oct 24 16:39:26 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_RPiList-Phishing.txt - 260230 addresses
Oct 24 16:39:27 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_adguarddns.txt - 56793 addresses
Oct 24 16:39:27 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_admiral.txt - 1014 addresses
Oct 24 16:39:27 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_easylist.txt - 31553 addresses
Oct 24 16:39:27 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_easyprivacy.txt - 21601 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_prigent-crypto.txt - 16015 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_prigent_ads.txt - 3686 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /tmp/hosts/2Step_firebog_w2kbl.txt - 356 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /tmp/hosts/2Step_git_AssoEchap_stalkerware-indicators.txt - 851 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /tmp/hosts/2Step_git_notrack-malware.txt - 1141 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /jffs/hosts/2Step_git_porn_top1m.txt - 11868 addresses
Oct 24 16:39:28 dnsmasq[27166]: read /jffs/hosts/2Step_git_spam404_main-blacklist.txt - 8143 addresses
Oct 24 16:39:29 dnsmasq[27166]: read /jffs/hosts/2Step_hole_cert_pl_domains.txt - 149695 addresses
Oct 24 16:39:30 dnsmasq[27166]: read /jffs/hosts/2Step_phishing_army_blocklist_extended.txt - 146006 addresses
Oct 24 16:39:30 dnsmasq[27166]: read /jffs/hosts/dhcp.cfg01411c - 0 addresses
Oct 24 16:39:30 dnsmasq[27166]: read /jffs/hosts/file_adaway_hosts.txt - 6542 addresses
Oct 24 16:39:31 dnsmasq[27166]: read /jffs/hosts/file_frogeye_firstparty_trackers.txt - 14144 addresses
Oct 24 16:39:31 dnsmasq[27166]: read /jffs/hosts/file_git_CoinBlockerLists.txt - 3496 addresses
Oct 24 16:39:32 dnsmasq[27166]: read /jffs/hosts/file_git_StevenBlack_master_hosts.txt - 146531 addresses
Oct 24 16:39:32 dnsmasq[27166]: read /jffs/hosts/file_git_anudeepnd_adservers.txt - 42536 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_bigdargon_hostvn.txt - 19918 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_crazymax_spy.txt - 347 addresses
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 62 bytes
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_dandelionsprout_antimalware.txt - 22009 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_fademind_addrisk.txt - 2189 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_fademind_addspam_hosts.txt - 57 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_fademind_hosts_extras.txt - 2030 addresses
Oct 24 16:39:33 dnsmasq[27166]: read /jffs/hosts/file_git_fademind_uncheckads.txt - 9 addresses
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 105 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 115 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 66 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 64 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 65 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 64 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 80 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 77 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 79 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 63 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 63 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 63 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 62 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 63 bytes
Oct 24 16:39:33 dnsmasq[27166]: failed to allocate 61 bytes

Here is the syslog output:

Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]
Oct 24 16:39:35 out of memory [27166]

But the router's memory usage is still healthy:

binlocal@PSU-AX56U-1:/tmp# free
total used free shared buffers cached
Mem: 510384 375176 135208 60408 5048 88244
-/+ buffers/cache: 281884 228500
Swap: 0 0 0

Here is the top -m output:

Mem total:510384 anon:107480 map:9172 free:134264
slab:135132 buf:5048 cache:88256 dirty:0 write:0
Swap total:0 free:0
PID VSZ^VSZRW RSS (SHR) DIRTY (SHR) STACK COMMAND
30844 66516 64604 65852 1584 64420 152 132 dnsmasq --log-async
1297 13276 3044 3784 3284 500 0 132 conn_diag
1154 13276 3044 3836 3348 488 0 132 /sbin/netool
1 12844 2616 5728 3744 1972 0 824 /sbin/init
1152 12812 2844 2500 2112 380 0 132 nt_monitor
1269 12260 4628 7216 2680 4472 0 132 networkmap --bootwait
1232 11228 1000 4148 3588 560 0 132 watchdog
1290 11228 1000 3812 3288 524 0 132 pctime
1565 11228 1000 3872 3352 520 0 132 ntp
1140 11228 1000 4048 3532 516 0 132 /sbin/wanduck
1233 11228 1000 3780 3272 508 0 132 check_watchdog
7475 11228 1000 3768 3276 492 0 132 amas_lib
11148 11228 1000 3844 3260 492 0 132 dhcpc_lease old 3c:28:b7:eb:80:89 10.10.10.51
1158 11228 1000 3784 3304 480 0 132 roamast
1205 11228 1000 3668 3192 476 0 132 wpsaide
1273 11228 1000 3704 3228 476 0 132 bwdpi_check
1086 11228 1000 3576 3104 472 0 132 console
1094 11228 1000 3620 3148 472 0 132 /sbin/PS_pod
1197 10992 1896 3416 2276 660 0 132 nt_center

Would anyone let me know the limit of addn-hosts limit in dnsmasq? I can't find the answer on Google search.

Thanks.