Re: [PATCH] tcp: restore correct limit

[Michal Simek <monstr@monstr.eu>]

On 04/10/2012 12:29 PM, Jason Wang wrote:
> On 04/10/2012 06:14 PM, Michal Simek wrote:
>> On 04/10/2012 12:03 PM, Eric Dumazet wrote:
>>> Commit c43b874d5d714f (tcp: properly initialize tcp memory limits)
>>> added a regression on machines with low amount of memory, since sockets
>>> cant use 1/128 of memory but 1/1024
>>>
>>> Fix this to match comment and previous behavior.
>>>
>>> Signed-off-by: Eric Dumazet<eric.dumazet@gmail.com>
>>> Cc: Jason Wang<jasowang@redhat.com>
>>> Cc: Glauber Costa<glommer@parallels.com>
>>> ---
>>> net/ipv4/tcp.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
>>> index 5d54ed3..67d726e 100644
>>> --- a/net/ipv4/tcp.c
>>> +++ b/net/ipv4/tcp.c
>>> @@ -3302,7 +3302,7 @@ void __init tcp_init(void)
>>>
>>> tcp_init_mem(&init_net);
>>> /* Set per-socket limits to no more than 1/128 the pressure threshold */
>>> - limit = nr_free_buffer_pages()<< (PAGE_SHIFT - 10);
>>> + limit = nr_free_buffer_pages()<< (PAGE_SHIFT - 7);
>>> limit = max(limit, 128UL);
>>> max_share = min(4UL*1024*1024, limit);
>>>
>>
>> hw design with csum is also much better.
>> Tested-by: Michal Simek <monstr@monstr.eu>
>>
>> Thanks for help,
>> Michal
>>
>>
>>
>>
>>
> Hi Michal and Eric:
>
> Which version of kernel did you test, did you try the newest kernel? The reason I use (PAGE_SHIFT - 10) is in the commit before 3dc43e3, the limit were calculated with:

I have tested it on 3.4.0-rc2.

Michal

-- 
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
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