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authorLukas Larsson <[email protected]>2018-08-03 09:41:25 +0200
committerLukas Larsson <[email protected]>2018-08-03 09:41:25 +0200
commitc33d4c7539a1681cfbc024d8637e204c0a05fd1a (patch)
treef6e41b31137f3c5fc2657a2016ea5caf3f5cbc8d
parent795d6ea47785a4e833e8c7829e67f48816f6372a (diff)
parenta9d361b4be7d6329bedd7b37d454c1abf4f27233 (diff)
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Merge branch 'lukas/erts/fix_udp_realloc_bug' into maint
* lukas/erts/fix_udp_realloc_bug: erts: Limit the automatic max buffer for UDP to 2^16 erts: Free udp buffer when getting EAGAIN
-rw-r--r--erts/emulator/drivers/common/inet_drv.c39
-rw-r--r--lib/kernel/doc/src/inet.xml19
-rw-r--r--lib/kernel/test/gen_udp_SUITE.erl12
3 files changed, 50 insertions, 20 deletions
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 5e9afdc5ca..2048d0f625 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -1549,6 +1549,8 @@ static void *realloc_wrapper(void *current, ErlDrvSizeT size){
# define LOAD_ASSOC_ID LOAD_UINT
# define LOAD_ASSOC_ID_CNT LOAD_UINT_CNT
# define SCTP_ANC_BUFF_SIZE INET_DEF_BUFFER/2 /* XXX: not very good... */
+#else
+# define IS_SCTP(desc) 0
#endif
#ifdef HAVE_UDP
@@ -1785,6 +1787,7 @@ static void release_buffer(ErlDrvBinary* buf)
#ifdef HAVE_UDP
static ErlDrvBinary* realloc_buffer(ErlDrvBinary* buf, ErlDrvSizeT newsz)
{
+ DEBUGF(("realloc_buffer: %ld -> %ld\r\n", (buf==NULL) ? 0 : buf->orig_size, newsz));
return driver_realloc_binary(buf, newsz);
}
#endif
@@ -6435,7 +6438,12 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
(long)desc->port, desc->s, res));
if (type == SO_RCVBUF) {
/* make sure we have desc->bufsz >= SO_RCVBUF */
- if (ival > desc->bufsz)
+ if (ival > (1 << 16) && desc->stype == SOCK_DGRAM && !IS_SCTP(desc))
+ /* For UDP we don't want to automatically
+ set the buffer size to be larger than
+ the theoretical max MTU */
+ desc->bufsz = 1 << 16;
+ else if (ival > desc->bufsz)
desc->bufsz = ival;
}
}
@@ -12042,15 +12050,11 @@ static int packet_inet_input(udp_descriptor* udesc, HANDLE event)
sys_memzero((char *) &other, sizeof(other));
/* udesc->i_buf is only kept between SCTP fragments */
- if (udesc->i_buf == NULL) {
- udesc->i_bufsz = desc->bufsz + len;
- if ((udesc->i_buf = alloc_buffer(udesc->i_bufsz)) == NULL)
- return packet_error(udesc, ENOMEM);
- /* pointer to message start */
- udesc->i_ptr = udesc->i_buf->orig_bytes + len;
- } else {
- ErlDrvBinary* tmp;
+#ifdef HAVE_SCTP
+ if (udesc->i_buf != NULL) {
+ ErlDrvBinary* tmp;
int bufsz;
+ ASSERT(IS_SCTP(desc));
bufsz = desc->bufsz + (udesc->i_ptr - udesc->i_buf->orig_bytes);
if ((tmp = realloc_buffer(udesc->i_buf, bufsz)) == NULL) {
release_buffer(udesc->i_buf);
@@ -12062,6 +12066,15 @@ static int packet_inet_input(udp_descriptor* udesc, HANDLE event)
udesc->i_buf = tmp;
udesc->i_bufsz = bufsz;
}
+ } else
+#endif
+ {
+ ASSERT(udesc->i_buf == NULL);
+ udesc->i_bufsz = desc->bufsz + len;
+ if ((udesc->i_buf = alloc_buffer(udesc->i_bufsz)) == NULL)
+ return packet_error(udesc, ENOMEM);
+ /* pointer to message start */
+ udesc->i_ptr = udesc->i_buf->orig_bytes + len;
}
/* Note: On Windows NT, recvfrom() fails if the socket is connected. */
@@ -12120,6 +12133,14 @@ static int packet_inet_input(udp_descriptor* udesc, HANDLE event)
) {
sock_select(desc,FD_READ,1);
}
+#ifdef HAVE_SCTP
+ if (!short_recv) {
+#endif
+ release_buffer(udesc->i_buf);
+ udesc->i_buf = NULL;
+#ifdef HAVE_SCTP
+ }
+#endif
return count; /* strange, not ready */
}
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml
index e6a7962c5a..f281d61459 100644
--- a/lib/kernel/doc/src/inet.xml
+++ b/lib/kernel/doc/src/inet.xml
@@ -734,22 +734,23 @@ get_tcpi_sacked(Sock) ->
</item>
<tag><c>{buffer, Size}</c></tag>
<item>
- <p>The size of the user-level software buffer used by
- the driver.
- Not to be confused with options <c>sndbuf</c>
+ <p>The size of the user-level buffer used by
+ the driver. Not to be confused with options <c>sndbuf</c>
and <c>recbuf</c>, which correspond to the
- Kernel socket buffers. It is recommended
- to have <c>val(buffer) &gt;= max(val(sndbuf),val(recbuf))</c> to
+ Kernel socket buffers. For TCP it is recommended
+ to have <c>val(buffer) &gt;= val(recbuf)</c> to
avoid performance issues because of unnecessary copying.
+ For UDP the same recommendation applies, but the max should
+ not be larger than the MTU of the network path.
<c>val(buffer)</c> is automatically set to the above
- maximum when values <c>sndbuf</c> or <c>recbuf</c> are set.
- However, as the sizes set for <c>sndbuf</c> and <c>recbuf</c>
+ maximum when <c>recbuf</c> is set.
+ However, as the size set for <c>recbuf</c>
usually become larger, you are encouraged to use
<seealso marker="#getopts/2"><c>getopts/2</c></seealso>
to analyze the behavior of your operating system.</p>
<p>Note that this is also the maximum amount of data that can be
- received from a single recv call. If you are using higher than
- normal MTU consider setting buffer higher.</p>
+ received from a single recv call. If you are using higher than
+ normal MTU consider setting buffer higher.</p>
</item>
<tag><c>{delay_send, Boolean}</c></tag>
<item>
diff --git a/lib/kernel/test/gen_udp_SUITE.erl b/lib/kernel/test/gen_udp_SUITE.erl
index b39399b18a..3acfff929e 100644
--- a/lib/kernel/test/gen_udp_SUITE.erl
+++ b/lib/kernel/test/gen_udp_SUITE.erl
@@ -34,7 +34,7 @@
-export([init_per_testcase/2, end_per_testcase/2]).
-export([send_to_closed/1, active_n/1,
- buffer_size/1, binary_passive_recv/1, bad_address/1,
+ buffer_size/1, binary_passive_recv/1, max_buffer_size/1, bad_address/1,
read_packets/1, open_fd/1, connect/1, implicit_inet6/1,
local_basic/1, local_unbound/1,
local_fdopen/1, local_fdopen_unbound/1, local_abstract/1]).
@@ -44,7 +44,7 @@ suite() ->
{timetrap,{minutes,1}}].
all() ->
- [send_to_closed, buffer_size, binary_passive_recv,
+ [send_to_closed, buffer_size, binary_passive_recv, max_buffer_size,
bad_address, read_packets, open_fd, connect,
implicit_inet6, active_n,
{group, local}].
@@ -237,6 +237,14 @@ buffer_size_server_recv(Socket, IP, Port, Cnt) ->
end.
+%%-------------------------------------------------------------
+%% OTP-15206: Keep buffer small for udp
+%%-------------------------------------------------------------
+max_buffer_size(Config) when is_list(Config) ->
+ {ok, Socket} = gen_udp:open(0, [binary]),
+ ok = inet:setopts(Socket,[{recbuf, 1 bsl 20}]),
+ {ok, [{buffer, 65536}]} = inet:getopts(Socket,[buffer]),
+ gen_udp:close(Socket).
%%-------------------------------------------------------------
%% OTP-3823 gen_udp:recv does not return address in binary mode