From: Miquel van Smoorenburg <mikevs@xs4all.net>
To: linux-nfs@vger.kernel.org
Cc: Trond.Myklebust@netapp.com, bfields@fieldses.org, neilb@suse.de,
mikevs@xs4all.net
Subject: Re: nfs/sunrpc: high CPU usage in rpcauth_lookup_credcache with lots of uids [PATCH]
Date: Mon, 22 Jun 2009 15:09:08 +0200 [thread overview]
Message-ID: <1245676148.5413.1.camel@laptop> (raw)
In-Reply-To: <20090602142933.GA27312@xs4all.net>
On Tue, 2009-06-02 at 16:29 +0200, Miquel van Smoorenburg wrote:
> [repost, with more people in the cc: list]
>
> We run a cluster of POP and IMAP servers that are used by
> hundreds of thousands of different users- we see as much
> as 80.000 different users per server on any given day.
>
> We noticed a high CPU load on these servers, sometimes near
> 100% system time being used on all cores. I used oprofile to
> find out where the CPU was being burned and it turned out to
> be in rpcauth_lookup_credcache(). The credential cache hashtable
> is sized way to small for our purposes- it's just 16 slots,
> and with 100.000 entries in the generic and unix credential
> caches the chainlength goes over 6000.
ping ?
Mike.
next prev parent reply other threads:[~2009-06-22 13:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-02 14:29 nfs/sunrpc: high CPU usage in rpcauth_lookup_credcache with lots of uids [PATCH] Miquel van Smoorenburg
2009-06-22 13:09 ` Miquel van Smoorenburg [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-05-23 17:11 Miquel van Smoorenburg
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