From: Roland Dreier <rdreier@cisco.com>
To: Joachim Fenkes <fenkes@de.ibm.com>
Cc: LinuxPPC-Dev <linuxppc-dev@ozlabs.org>,
LKML <linux-kernel@vger.kernel.org>,
OF-General <general@lists.openfabrics.org>
Subject: Re: [PATCH] eHCA: Add "Modify Port" verb
Date: Mon, 23 Apr 2007 12:20:14 -0700 [thread overview]
Message-ID: <ada3b2q7v9t.fsf@cisco.com> (raw)
In-Reply-To: <200704231823.48723.fenkes@de.ibm.com> (Joachim Fenkes's message of "Mon, 23 Apr 2007 18:23:48 +0200")
> + if (hipz_h_query_port(shca->ipz_hca_handle, port, rblock) != H_SUCCESS) {
> + ehca_err(&shca->ib_device, "Can't query port properties");
> + ret = -EINVAL;
> + goto modify_port1;
> + }
> +
> + cap = (rblock->capability_mask | props->set_port_cap_mask)
> + & ~props->clr_port_cap_mask;
> +
> + hret = hipz_h_modify_port(shca->ipz_hca_handle, port,
> + cap, props->init_type, port_modify_mask);
Is this thread-safe? What if two different bits are set at the same
time from two different threads? It seems that both calls could get
the same result from hipz_h_query_port(), and then the second call to
hipz_h_modify_port() would overwrite the first call.
You could look at the implementation in mthca to see the locking I
used there.
- R.
WARNING: multiple messages have this Message-ID (diff)
From: Roland Dreier <rdreier@cisco.com>
To: Joachim Fenkes <fenkes@de.ibm.com>
Cc: "LinuxPPC-Dev" <linuxppc-dev@ozlabs.org>,
LKML <linux-kernel@vger.kernel.org>,
"OF-General" <general@lists.openfabrics.org>,
Roland Dreier <rolandd@cisco.com>,
"Hoang-Nam Nguyen" <hnguyen@de.ibm.com>
Subject: Re: [PATCH] eHCA: Add "Modify Port" verb
Date: Mon, 23 Apr 2007 12:20:14 -0700 [thread overview]
Message-ID: <ada3b2q7v9t.fsf@cisco.com> (raw)
In-Reply-To: <200704231823.48723.fenkes@de.ibm.com> (Joachim Fenkes's message of "Mon, 23 Apr 2007 18:23:48 +0200")
> + if (hipz_h_query_port(shca->ipz_hca_handle, port, rblock) != H_SUCCESS) {
> + ehca_err(&shca->ib_device, "Can't query port properties");
> + ret = -EINVAL;
> + goto modify_port1;
> + }
> +
> + cap = (rblock->capability_mask | props->set_port_cap_mask)
> + & ~props->clr_port_cap_mask;
> +
> + hret = hipz_h_modify_port(shca->ipz_hca_handle, port,
> + cap, props->init_type, port_modify_mask);
Is this thread-safe? What if two different bits are set at the same
time from two different threads? It seems that both calls could get
the same result from hipz_h_query_port(), and then the second call to
hipz_h_modify_port() would overwrite the first call.
You could look at the implementation in mthca to see the locking I
used there.
- R.
next prev parent reply other threads:[~2007-04-23 19:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-23 16:23 [PATCH] eHCA: Add "Modify Port" verb Joachim Fenkes
2007-04-23 16:23 ` Joachim Fenkes
2007-04-23 16:55 ` [ofa-general] " Hal Rosenstock
2007-04-23 16:55 ` Hal Rosenstock
2007-04-24 21:48 ` Christoph Raisch
2007-04-24 21:48 ` Christoph Raisch
2007-04-23 19:20 ` Roland Dreier [this message]
2007-04-23 19:20 ` Roland Dreier
2007-04-24 12:25 ` Joachim Fenkes
2007-04-24 12:25 ` Joachim Fenkes
-- strict thread matches above, loose matches on Subject: below --
2007-04-24 15:44 Joachim Fenkes
2007-04-24 15:44 ` Joachim Fenkes
2007-04-24 17:52 ` Roland Dreier
2007-04-24 17:52 ` Roland Dreier
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