netdev - Re: TCP_DEFER_ACCEPT is missing counter update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 16 Oct 2009 05:51:16 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Julian Anastasov <ja@....bg>
CC:	Willy Tarreau <w@....eu>, David Miller <davem@...emloft.net>,
	netdev@...r.kernel.org
Subject: Re: TCP_DEFER_ACCEPT is missing counter update

Julian Anastasov a écrit :
> 	Sorry for the long mail ...
> 
> 	I was not clear enough in previous email. Your goal
> is to decrease period per client while the actually decreased
> threshold is on the listener's socket. 256 conns will be enough
> to completely disable TCP_DEFER_ACCEPT on the listener (u8). I'm not
> sure that you tested what happens after Nth client (where
> N matches your TCP_DEFER_ACCEPT value as retransmissions), do you
> still see accept deferring for next clients? Now if your patch
> is applied the deferring will be disabled soon after server start.


So, it appears defer_accept value is not an inherited attribute,
but shared by all embryons. Therefore we should not touch it.

No need to type so much text Julian.

Of course it should be done, or add a new connection field to count number
of pure ACKS received on each SYN_RECV embryon.

Do you volunter for this patch ?
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html