Regarding temporary "pauses", perhaps due to using an SD card with an XO
devel.chm.01 at gmail.com
Mon Oct 15 08:12:07 EDT 2012
If I umount the SD card then the hang/pause-s
stop. Of course, I than have no extra storage space
for the XO.
It would seem that there may be a system
or kernel call that gets blocked by something
related to the SD card mount.
On 10/13/12, Chris Marshall <devel.chm.01 at gmail.com> wrote:
> I too have observed increasingly often "pauses"
> on my XO but have had no idea how or where to
> start to debug the problem.
> One thought I had is that the swap file on the SD
> card is the source of the problem (somehow) but
> I still have the pernicious/persistent hanging even
> without using the swapfile.
> I'll try with a brand new 16GB SD card to see if
> that helps.
> On 10/13/12, Mikus Grinbergs <mikus at bga.com> wrote:
>> Lately there has been discussion about using an SD card to expand the
>> "storage" capability of the XO. [For instance, discussion of when an XO
>> functions as a server, having it keep its database on an SD card.]
>> What I want to mention is that I experience occasional "pauses" on my XO
>> systems (each has a "permanent" SD card, on which I keep Activities,
>> Linux executables, etc.). I do not know what causes these "pauses", but
>> my best guess is the following (particularly since "pauses" often occur
>> during a CLI command that is "massively" accessing the SD card).
>> My guess: SD cards have an "embedded chip" which is responsible for
>> "wear levelling" the electronic components used to keep the data. It
>> does this by internally 'rearranging' "which data block is physically
>> kept where". I think this 'rearranging' action by the "embedded chip"
>> gets launched (when some 'internal' SD card thresholds are met) during
>> an I/O access by the (XO) host -- and this "rearranging" results in that
>> host's I/O access being DELAYED until the "embedded chip" is done.
>> I have not compared the "performance" (from the user's point of view) of
>> running an Activity "from the SD card" vs. running it "from the XO".
>> But I do have the impression that the duration of the occasional
>> "pauses" which I as a user notice while running "with the SD card" have
>> gotten LONGER as my XOs have migrated to using ever-larger SD cards.
>> Devel mailing list
>> Devel at lists.laptop.org
More information about the Devel