Return-path: Received: from mga09.intel.com ([134.134.136.24]:64952 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751253Ab0FYS5K (ORCPT ); Fri, 25 Jun 2010 14:57:10 -0400 Subject: Re: intel 5100/iwlagn bug in 2.6.35-rc2 during large file transfer From: reinette chatre To: Richard Farina Cc: "linux-wireless@vger.kernel.org" In-Reply-To: <4C24D926.7010806@gmail.com> References: <4C198EF0.5080807@gmail.com> <1277225293.25793.2257.camel@rchatre-DESK> <4C2383E2.8000909@gmail.com> <1277399636.25793.2389.camel@rchatre-DESK> <4C23961D.7050500@gmail.com> <1277401731.25793.2391.camel@rchatre-DESK> <4C24D926.7010806@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 25 Jun 2010 11:57:09 -0700 Message-ID: <1277492229.13673.1297.camel@rchatre-DESK> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2010-06-25 at 09:28 -0700, Richard Farina wrote: > reinette chatre wrote: > > On Thu, 2010-06-24 at 10:30 -0700, Richard Farina wrote: > I've added this patch to my system. I'm about 5GB into a download right > now and here are the issues. First, and relatively quickly this line > showed up in dmesg: > [ 1589.605470] CE: hpet increased min_delta_ns to 7500 nsec I googled a bit for this string and found a few mentions where it is connected to system hangs. I do not know if you are running into the same issue as these people (did not spend much time reading through all the bug reports), but I did notice that sometimes the people were able to work around the issue by booting with a different clock source (eg. clocksource=jiffies) or disabling hpet (eg. hpet=disable). I am very unfamiliar with this aspect so if this is giving you issues I'd propose you go to lkml or kernel.org bugzilla. > I've been carefully monitoring my system and I have loads of RAM spare. > Things have been much smoother but the system still freezes up for a few > seconds at a time. Mind you, this is an improvement as the freezes are > slightly less frequent and before the patch the freezes were hitting the > 120s hangcheck timer in the kernel and now they last like 20-60 seconds. > > I finally managed to trigger the oops again but it does seem that it > took much longer this time. Pasted at the bottom. (please note the > timestamps included are accurate to show the time difference bettween > the hpet warning and the oops). They seem pretty far apart so may not be related ... > > What else can I do to provide useful information? Or do you just want to > update the thresholds again? Sure ... let's try that. Patch is below. I also made things less noisy when it does fail in atomic. > > Thanks, > Rick Farina > > PS> The patch does look at bit odd as you change RX_LOW_WATERMARK while > at the same time removing one of the places that uses it. I'm sure that > is on purpose just seems odd to me as I don't understand. That was on purpose. Since I increased the watermark I did not want to increase the threshold used to print warnings to the user also. That is why I just made that a hard 8 so that if memory allocation fails we will only start seeing the dumps when we are down to 8 buffers and not the new high watermark. --- drivers/net/wireless/iwlwifi/iwl-agn-lib.c | 5 +++-- drivers/net/wireless/iwlwifi/iwl-fh.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c index 0f292a2..2815ee7 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c @@ -613,7 +613,8 @@ void iwlagn_rx_allocate(struct iwl_priv *priv, gfp_t priority) } spin_unlock_irqrestore(&rxq->lock, flags); - if (rxq->free_count > RX_LOW_WATERMARK) + if ((priority == GFP_ATOMIC) || + (rxq->free_count > RX_LOW_WATERMARK / 4)) gfp_mask |= __GFP_NOWARN; if (priv->hw_params.rx_page_order > 0) @@ -627,7 +628,7 @@ void iwlagn_rx_allocate(struct iwl_priv *priv, gfp_t priority) "order: %d\n", priv->hw_params.rx_page_order); - if ((rxq->free_count <= RX_LOW_WATERMARK) && + if ((rxq->free_count <= RX_LOW_WATERMARK / 4) && net_ratelimit()) IWL_CRIT(priv, "Failed to alloc_pages with %s. Only %u free buffers remaining.\n", priority == GFP_ATOMIC ? "GFP_ATOMIC" : "GFP_KERNEL", diff --git a/drivers/net/wireless/iwlwifi/iwl-fh.h b/drivers/net/wireless/iwlwifi/iwl-fh.h index 113c366..431bc58 100644 --- a/drivers/net/wireless/iwlwifi/iwl-fh.h +++ b/drivers/net/wireless/iwlwifi/iwl-fh.h @@ -426,7 +426,7 @@ * RX related structures and functions */ #define RX_FREE_BUFFERS 64 -#define RX_LOW_WATERMARK 8 +#define RX_LOW_WATERMARK 128 /* Size of one Rx buffer in host DRAM */ #define IWL_RX_BUF_SIZE_3K (3 * 1000) /* 3945 only */ -- 1.7.0.4