Re: [v3,6/9] mm/page_owner: use stackdepot to store stacktrace

From: Sascha Silbe
Date: Wed Oct 26 2016 - 09:13:09 EST


Dear Joonsoo,

Joonsoo Kim <js1304@xxxxxxxxx> writes:

> Currently, we store each page's allocation stacktrace on corresponding
> page_ext structure and it requires a lot of memory. This causes the
> problem that memory tight system doesn't work well if page_owner is
> enabled. Moreover, even with this large memory consumption, we cannot get
> full stacktrace because we allocate memory at boot time and just maintain
> 8 stacktrace slots to balance memory consumption. We could increase it to
> more but it would make system unusable or change system behaviour.
[...]

This patch causes my Wandboard Quad [1] not to boot anymore. I don't get
any kernel output, even with earlycon enabled
(earlycon=ec_imx6q,0x02020000). git bisect pointed towards your patch;
reverting the patch causes the system to boot fine again. Config is
available at [2]; none of the defconfigs I tried (defconfig =
multi_v7_defconfig, imx_v6_v7_defconfig) works for me.

Haven't looked into this any further so far; hooking up a JTAG adapter
requires some hardware changes as the JTAG header is unpopulated.

Sascha

PS: Please CC me on replies; I'm not subscribed to any of the lists.

[1] http://www.wandboard.org/index.php/details/wandboard
[2] https://sascha.silbe.org/tmp/config-4.8.4-wandboard-28-00003-g9e9b5d6
--
Softwareentwicklung Sascha Silbe, NiederhofenstraÃe 5/1, 71229 Leonberg
https://se-silbe.de/
USt-IdNr.: DE281696641

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