Re: [PATCH v2] net/core: Increase default optmem_max limit

[Stephan Mueller]

Am Dienstag, 16. Januar 2018, 18:16:43 CET schrieb Björn 'besser82' Esser:

Hi Björn,

> 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>

Considering NR_FILE defining the default maximum number of file descriptors, 
at max 335 MB of RAM (32 bit) or 670 MB (64 bit) could be allocated which I 
would assume to be ok in current systems.

Reviewed-by: Stephan Mueller <smueller@xxxxxxxxxx>

Ciao
Stephan