netdev - Re: [PATCH net-next 2/5] ionic: smaller coalesce default

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:   Mon, 31 Aug 2020 17:16:13 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     kuba@...nel.org
Cc:     snelson@...sando.io, netdev@...r.kernel.org
Subject: Re: [PATCH net-next 2/5] ionic: smaller coalesce default

From: Jakub Kicinski <kuba@...nel.org>
Date: Mon, 31 Aug 2020 16:50:54 -0700

> On Mon, 31 Aug 2020 16:35:55 -0700 Shannon Nelson wrote:
>> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
>> index 9e2ac2b8a082..2b2eb5f2a0e5 100644
>> --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
>> +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
>> @@ -16,7 +16,7 @@
>>  #define IONIC_DEF_TXRX_DESC		4096
>>  #define IONIC_LIFS_MAX			1024
>>  #define IONIC_WATCHDOG_SECS		5
>> -#define IONIC_ITR_COAL_USEC_DEFAULT	64
>> +#define IONIC_ITR_COAL_USEC_DEFAULT	8
> 
> 8 us interrupt coalescing does not hurt general operations?! No way.
> 
> It's your customers who'll get hurt here, so your call, but I seriously
> doubt this. Unless the unit is not usec?

Agreed, 8usec is really really low.  You won't get much coalescing during
bulk transfers with a value like that, eliminating the gain from coalescing
in the first place.