applied to acpi-test

thanks,
-len

On Wed, 22 Oct 2008, Venki Pallipadi wrote:

>
>
> Cleanup of i7300 idle driver based on review comments from Randy Dunlap,
> Andi Kleen and Len Brown.
>
> Signed-off-by: Venkatesh Pallipadi <[email protected]>
>
> ---
> drivers/idle/Kconfig | 11 ++++++-----
> drivers/idle/i7300_idle.c | 33 ++++++++++++++++++---------------
> 2 files changed, 24 insertions(+), 20 deletions(-)
>
> Index: linux-acpi-2.6/drivers/idle/Kconfig
> ===================================================================
> --- linux-acpi-2.6.orig/drivers/idle/Kconfig 2008-10-22 11:43:08.000000000 -0700
> +++ linux-acpi-2.6/drivers/idle/Kconfig 2008-10-22 11:43:37.000000000 -0700
> @@ -5,12 +5,13 @@ config I7300_IDLE_IOAT_CHANNEL
> bool
>
> config I7300_IDLE
> - tristate "Intel chipset idle power saving driver"
> + tristate "Intel chipset idle memory power saving driver"
> select I7300_IDLE_IOAT_CHANNEL
> - depends on X86_64
> + depends on X86_64 && EXPERIMENTAL
> help
> - Enable idle power savings with certain Intel server chipsets.
> - The chipset must have I/O AT support, such as the Intel 7300.
> - The power savings depends on the type and quantity of DRAM devices.
> + Enable memory power savings when idle with certain Intel server
> + chipsets. The chipset must have I/O AT support, such as the
> + Intel 7300. The power savings depends on the type and quantity of
> + DRAM devices.
>
> endmenu
> Index: linux-acpi-2.6/drivers/idle/i7300_idle.c
> ===================================================================
> --- linux-acpi-2.6.orig/drivers/idle/i7300_idle.c 2008-10-22 11:43:08.000000000 -0700
> +++ linux-acpi-2.6/drivers/idle/i7300_idle.c 2008-10-22 11:43:37.000000000 -0700
> @@ -35,6 +35,8 @@
> #define I7300_IDLE_DRIVER_VERSION "1.55"
> #define I7300_PRINT "i7300_idle:"
>
> +#define MAX_STOP_RETRIES 10
> +
> static int debug;
> module_param_named(debug, debug, uint, 0644);
> MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
> @@ -47,12 +49,12 @@ MODULE_PARM_DESC(debug, "Enable debug pr
> * 0 = No throttling
> * 1 = Throttle when > 4 activations per eval window (Maximum throttling)
> * 2 = Throttle when > 8 activations
> - * 168 = Throttle when > 168 activations (Minimum throttling)
> + * 168 = Throttle when > 672 activations (Minimum throttling)
> */
> -#define MAX_THRTLWLIMIT 168
> -static uint i7300_idle_thrtlowlm = 1;
> -module_param_named(thrtlwlimit, i7300_idle_thrtlowlm, uint, 0644);
> -MODULE_PARM_DESC(thrtlwlimit,
> +#define MAX_THROTTLE_LOW_LIMIT 168
> +static uint throttle_low_limit = 1;
> +module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644);
> +MODULE_PARM_DESC(throttle_low_limit,
> "Value for THRTLOWLM activation field "
> "(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)");
>
> @@ -111,9 +113,9 @@ static int i7300_idle_ioat_start(void)
> static void i7300_idle_ioat_stop(void)
> {
> int i;
> - u8 sts;
> + u64 sts;
>
> - for (i = 0; i < 5; i++) {
> + for (i = 0; i < MAX_STOP_RETRIES; i++) {
> writeb(IOAT_CHANCMD_RESET,
> ioat_chanbase + IOAT1_CHANCMD_OFFSET);
>
> @@ -127,9 +129,10 @@ static void i7300_idle_ioat_stop(void)
>
> }
>
> - if (i == 5)
> - dprintk("failed to suspend+reset I/O AT after 5 retries\n");
> -
> + if (i == MAX_STOP_RETRIES) {
> + dprintk("failed to stop I/O AT after %d retries\n",
> + MAX_STOP_RETRIES);
> + }
> }
>
> /* Test I/O AT by copying 1024 byte from 2k to 1k */
> @@ -276,7 +279,7 @@ static void __exit i7300_idle_ioat_exit(
> i7300_idle_ioat_stop();
>
> /* Wait for a while for the channel to halt before releasing */
> - for (i = 0; i < 10; i++) {
> + for (i = 0; i < MAX_STOP_RETRIES; i++) {
> writeb(IOAT_CHANCMD_RESET,
> ioat_chanbase + IOAT1_CHANCMD_OFFSET);
>
> @@ -390,9 +393,9 @@ static void i7300_idle_start(void)
> new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT;
> pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
>
> - limit = i7300_idle_thrtlowlm;
> - if (unlikely(limit > MAX_THRTLWLIMIT))
> - limit = MAX_THRTLWLIMIT;
> + limit = throttle_low_limit;
> + if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT))
> + limit = MAX_THROTTLE_LOW_LIMIT;
>
> pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit);
>
> @@ -441,7 +444,7 @@ static int i7300_idle_notifier(struct no
> static ktime_t idle_begin_time;
> static int time_init = 1;
>
> - if (!i7300_idle_thrtlowlm)
> + if (!throttle_low_limit)
> return 0;
>
> if (unlikely(time_init)) {
> --
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>

2008-10-28 16:30:41

by Sosnowski, Maciej

[permalink] [raw]

Subject: RE: [PATCH] Disable ioat channel only on platforms where ile driver can load

> ---------- Original message ----------
> From: Venki Pallipadi <[email protected]>
> Date: Oct 23, 2008 12:34 AM
> Subject: [PATCH] Disable ioat channel only on platforms where ile
> driver can load
> To: Andi Kleen <[email protected]>
> Cc: "Pallipadi, Venkatesh" <[email protected]>, Len Brown
> <[email protected]>, Ingo Molnar <[email protected]>,
> "[email protected]" <[email protected]>, Linux
> Kernel Mailing List <[email protected]>, "Henroid, Andrew
> D" <[email protected]>, Linus Torvalds
> <[email protected]>, Thomas Gleixner <[email protected]>,
> "H. Peter Anvin" <[email protected]>
>
>
> On Wed, Oct 22, 2008 at 12:19:22AM -0700, Andi Kleen wrote:
>> Pallipadi, Venkatesh wrote:
>>>
>>>>> +#if CONFIG_I7300_IDLE_IOAT_CHANNEL
>>>>> + device->common.chancnt--;
>>>>> +#endif
>>>> I still think this lone decrement looks fishy. Can there please be
>>>> some explanation how it exactly relates to the i7300 idle driver,
>>>> where the matching increment is, etc.?
>>>
>>> No. This is not a increment/decrement thing. It is basically
>>> telling other Users of IOAT that they have one IOAT channel less
>>> that they can use.
>>> The last IOAT channel is used by i7300 idle driver to get the
>>> throttling to work.
>>
>> Ok then it should be made conditional on the i7300 actually be
>> available
>> in the system? It looks like you do it always no matter what
>> chipset is in there.
>
> Does the patch below look OK?
>
> Thanks,
> Venki
>
> Based on input from Andi Kleen:
> share the platform detection code with ioat_dma and disable the
> channel in
> dma engine only for specific platforms.
>
> Signed-off-by: Venkatesh Pallipadi <[email protected]>
>
> ---

Hi Venki,

Why for your purposes don't you use dmaengine to request an ioatdma
channel from ioatdma driver?
This way sharing of this channel with other clients
(like TCP which uses ioatdma for receive offloading) would be possible .
In the previous approach your change was not acceptable from ioatdma
perspective
(for IOAT_VER_3_0 there are 8 ioat devices, each with single channel
- in this case you would take away all 8 channels and make ioat ver.3.0
totally disfunctional).
Even with this approach (assuming that it would affect IOAT_VER_1_2
only)
you reserve one channel of four statically for your purposes only,
leaving for TCP receive offloading 75% of ioatdma resources and thus
affecting its efficiency.

Dan, what do you think?

BTW, could you please next time in case of ioat/dmaengine changes
include Dan and me in the list?

Thanks,
Maciej

> Index: linux-acpi-2.6/drivers/dma/ioat_dma.c
> ===================================================================
> --- linux-acpi-2.6.orig/drivers/dma/ioat_dma.c 2008-10-22
> 11:42:04.000000000 -0700
> +++ linux-acpi-2.6/drivers/dma/ioat_dma.c 2008-10-22
> 11:42:46.000000000 -0700
> @@ -33,6 +33,7 @@
> #include <linux/delay.h>
> #include <linux/dma-mapping.h>
> #include <linux/workqueue.h>
> +#include <linux/i7300_idle.h>
> #include "ioatdma.h"
> #include "ioatdma_registers.h"
> #include "ioatdma_hw.h"
> @@ -172,7 +173,9 @@ static int ioat_dma_enumerate_channels(s
> xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
>
> #if CONFIG_I7300_IDLE_IOAT_CHANNEL
> - device->common.chancnt--;
> + if (i7300_idle_platform_probe(NULL, NULL) == 0) {
> + device->common.chancnt--;
> + }
> #endif
> for (i = 0; i < device->common.chancnt; i++) {
> ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);