On Mon, Aug 08, 2011 at 04:42:42PM +0530, RACHANA TEWARI wrote:
> Does anyone know way to initiate a bash script(to run on linux box) from
> windows Written in C#?
>
> How to write these Scripts...
This has nothing to do with CPU topology. Please do not topic hijack.
This is also off-topic for these mailing lists. You may wish to
consider posting your query to more appropriate mailing lists or forums
(eg, those dealing with C#). Thanks.
From: Per Forlin <per.forlin(a)linaro.org>
FSG_NUM_BUFFERS is set to 2 as default.
Usually 2 buffers are enough to establish a good
buffering pipeline. But when dealing with expensive
request preparation (i.e. dma_map) there may be benefits of
increasing the number of buffers. There is an extra cost for
every first request, the others are prepared in parallel with
an ongoing transfer. Every time all buffers are consumed there is
an additional cost for the first request. Increasing the number
of buffers decreases the risk of running out of buffers.
Test set up
* Running dd on the host reading from the mass storage device
* cmdline: dd if=/dev/sdb of=/dev/null bs=4k count=$((256*100))
* Caches are dropped on the host and on the device before each run
Measurements on a Snowball board with ondemand_govenor active.
FSG_NUM_BUFFERS 2
104857600 bytes (105 MB) copied, 5.62173 s, 18.7 MB/s
104857600 bytes (105 MB) copied, 5.61811 s, 18.7 MB/s
104857600 bytes (105 MB) copied, 5.57817 s, 18.8 MB/s
104857600 bytes (105 MB) copied, 5.57769 s, 18.8 MB/s
104857600 bytes (105 MB) copied, 5.59654 s, 18.7 MB/s
104857600 bytes (105 MB) copied, 5.58948 s, 18.8 MB/s
FSG_NUM_BUFFERS 4
104857600 bytes (105 MB) copied, 5.26839 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.2691 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.2711 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.27174 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.27261 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.27135 s, 19.9 MB/s
104857600 bytes (105 MB) copied, 5.27249 s, 19.9 MB/s
There may not be one optimal number for all boards. This is why
the number is added to Kconfig.
Signed-off-by: Per Forlin <per.forlin(a)linaro.org>
Acked-by: Michal Nazarewicz <mina86(a)mina86.com>
---
drivers/usb/gadget/Kconfig | 15 +++++++++++++++
drivers/usb/gadget/storage_common.c | 7 +++++--
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 029e288..1888a16 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -96,6 +96,21 @@ config USB_GADGET_VBUS_DRAW
This value will be used except for system-specific gadget
drivers that have more specific information.
+config USB_GADGET_STORAGE_NUM_BUFFERS
+ int "Number of storage pipeline buffers"
+ range 2 64
+ default 2
+ help
+ Usually 2 buffers are enough to establish a good
+ buffering pipeline. But when dealing with expensive
+ request preparation (i.e. dma_map) there may be benefits of
+ increasing the number of buffers. There is an extra cost for
+ every first request, the others are prepared in parallel with
+ an ongoing transfer. Every time all buffers are consumed there is
+ an additional cost for the first request. Increasing the number
+ of buffers decreases the risk of running out of buffers.
+ If unsure, say 2.
+
config USB_GADGET_SELECTED
boolean
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 1fa4f70..683c972 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -262,8 +262,11 @@ static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
#define EP0_BUFSIZE 256
#define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
-/* Number of buffers we will use. 2 is enough for double-buffering */
-#define FSG_NUM_BUFFERS 2
+/*
+ * Number of buffers we will use.
+ * 2 is usually enough for good buffering pipeline
+ */
+#define FSG_NUM_BUFFERS CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
/* Default size of buffer length. */
#define FSG_BUFLEN ((u32)16384)
--
1.7.4.1
Hi,
Our current default root file system, ext3, is proving to be a
bottleneck for SD card performance. Not only does it take a long time
to format the partitions, but it also takes a long time to write to.
This slows down creating images on SD cards a lot. I just did a very
simple experiment running linaro-media-create, writing an Ubuntu
Desktop image to an SD card:
ext3:
139.85user 35.27system 44:03.58elapsed 6%CPU (0avgtext+0avgdata
107360maxresident)k
2876115inputs+7048200outputs (958major+1677659minor)pagefaults 0swaps
btrfs:
146.52user 34.48system 19:57.16elapsed 15%CPU (0avgtext+0avgdata
107408maxresident)k
4417521inputs+6542992outputs (138major+1779874minor)pagefaults 0swaps
As I understand it, btrfs is considered OK for file systems running on
systems that don't suffer from power failure, so for writing an image
and testing it this should be fine.
So, what do people think about switching?
--
James Tunnicliffe
Hi,
I just spotted this bit in Android's Makefiles (inherited that way from AOSP):
TARGET_arm_CFLAGS := [...] -fstrict-aliasing [...]
[...]
TARGET_thumb_CFLAGS := [...] -fno-strict-aliasing [...]
This general assumption that arm code can handle strict aliasing, but
thumb code can't, seems odd.
My guess is that they started out using -fno-strict-aliasing
everywhere, then fixed aliasing violations and "fixed" the compiler
flags for arm, and didn't notice they're still turning it off for
thumb -- either that, or they've run into toolchain bugs (that might
be fixed in the Linaro toolchain), or it's a matter of "something
we're building in thumb mode has aliasing violations and we're too
lazy to figure out which part it is".
Unless someone knows of a valid reason for doing things the way they
did, simply taking it out (preferrably replacing it with
-Werror=strict-aliasing, so we're likely to notice any aliasing
violations if it comes down to "too lazy to figure out which part")
should get us some free extra speed. (Not sure just how much we're
actually building in thumb mode - may or may not be relevant.)
ttyl
bero
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hi all,
here is a few test scenario I would like to add to the pm-qa.
test_01: the sched_mc feature is enabled in the kernel
check the presence of the 'sched_mc_power_savings' file
test_02: the topology is implemented in the kernel
check the value of the physical_package_id file is different from "-1"
test_03: the topology files are present
check the presence of the topology files for each cpu:
* core_id
* core_siblings
* core_siblings_list
* physical_package_id
* thread_siblings
* thread_siblings_list
test_04: the change are effective for sched_mc
check the ability to change the value [0-2] of the
'sched_mc_power_savings' file
test_05: the topology is consistent
check the consistency of the topology files
* for each package:
* count the cores
-> the number of cores is 2 ^ (nr_cores - 1)
-> all core ids are between 0 and nr_cores - 1
Concerning the functional tests, I need some hints :)
On the architecture we have, that will be difficult to verify sched_mc
works as expected.
If I understood correctly, in order to test that, we should have a
dual Cortex-A9 to check a program with two processes eating a lot of
cpu cycles will be bounded in the same socket_id when
sched_mc_power_savings=2.
The other processor staying idle or not running any of these
processes, right ? AFAIK, there is no such hardware, no ?
- --
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> As I understand it, btrfs is considered OK for file systems running on
> systems that don't suffer from power failure, so for writing an image
> and testing it this should be fine.
>
> So, what do people think about switching?
I too would be considered about filesystem integrity given the number of
times I'm forced to yank the power cord on my board.
What speed class card are you using though? I tried a low-end one at
first and quickly decided the extra US$5 for a class 6 card (San Disk
Extreme) paid back the next time I used l-m-c.
-dl
forward to linaro-dev ml
---------- Forwarded message ----------
From: Frans Gifford <frans.gifford(a)linaro.org>
Date: 3 August 2011 11:55
Subject: ADB/Android Screencast
Hi all,
I assume most people have used ADB and had to create a udev rule to
set permissions on their board. We have a wiki page
(https://wiki.linaro.org/Platform/Android/ConfigureAndUseAdbOnPanda)
with the rules for Panda/TI and Snowball/ST-Ericsson, but it would be
nice if some of you could add the rules for the other boards/vendors
too so everything's in one place.
Also, I wrote a short wiki page yesterday about getting
androidscreencast running, it's a useful tool that lets you control an
android device remotely from a PC. Feel free to update this if I
missed anything out.
Regards,
Frans
--
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