With the new Linux Kernel Crypto API User Space Interface and its underlying AF_ALG socket, the current default value for `net.core.optmem_max` can be exhausted pretty quick when using asynchronous IO; on 32 bit systems it is not even enough for sending about 10 IOVECs at once to the socket interface. To provide consumers of this new user space interface a well sufficient and reasonable maximum ancillary buffer size per socket by default, the limit is increased to four times of the previous setting: * 32 bit systems: from 10240 bytes to 40960 bytes * 64 bit systems: from 20480 bytes to 81920 bytes This allows for sending 32/64 (32/64 bit) parallel IOVECs at once to the socket interface, which should be enough for use in real world applications. Signed-off-by: Björn Esser <besser82@xxxxxxxxxxxxxxxxx> --- net/core/sock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/sock.c b/net/core/sock.c index c0b5b2f17412..de00c571c933 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -316,7 +316,7 @@ __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX; __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX; /* Maximal space eaten by iovec or ancillary data plus some space */ -int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512); +int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*4*(2*UIO_MAXIOV+512); EXPORT_SYMBOL(sysctl_optmem_max); int sysctl_tstamp_allow_data __read_mostly = 1;
