On 12/1/23 16:30, 薛国伦 wrote:
Hi kazu:
I found that vmlinux of GKI kernel-6.1 which is newest version
in links below, it can make sure that nr_swapper_spaces not found.
https://ci.android.com/builds/submitted/11087000/kernel_aarch64/latest?hl=zh-cn
<https://ci.android.com/builds/submitted/11087000/kernel_aarch64/latest?hl=zh-cn>
Download vmlinux in links and run: readelf -a vmlinux | grep
nr_swapper_spaces
It's weird, I downloaded the vmlinux from the above link, got the
nr_swapper_spaces:
$ md5sum vmlinux
7d47aa96b3812e6ca607de7e297307a1 vmlinux
$ strings vmlinux |grep nr_swapper_spaces
nr_swapper_spaces
nr_swapper_spaces
nr_swapper_spaces
$ readelf -a vmlinux |grep nr_swapper_spaces
17111: c000000001856810 108 OBJECT LOCAL DEFAULT 47
nr_swapper_spaces
Has the vmlinux been updated again?
Thanks
Lianbo
can not find this symbol.
Thanks！
Best Regards
------------------------------------------------------------------------
*From:* 薛国伦
*Sent:* Friday, December 1, 2023 4:07:08 PM
*To:* HAGIO KAZUHITO(萩尾 一仁); devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx
*Cc:* Lianbo Jiang
*Subject:* Re: [External Mail]Re: [BUG FIXED]fix bug
of CACHED in kmem -i show memory
Hi kazu:
1. I know that kernel have nr_swapper_spaces since kernel 4.11 which
brought into kernel with struct address_space *swapper_spaces[]
my team think GKI vmlinux did not have nr_swapper_spaces this symbol,
may due to compile rule changed in AOSP code.
we will try to find the root cause of vmlinux without symbol name
nr_swappera_space.
>> RELEASE: 6.1.25-android14-11-maybe-dirty-qki-consolidate
>> crash> nr_swapper_spaces
>> crash: command not found: nr_swapper_spaces
2. I printf log of crash when execute kmem -i, it run into branch of
"symbol_exists("swapper_spaces")", also can not find nr_swapper_spaces
if (symbol_exists("nr_swapper_spaces") {
......
} else if (symbol_exists("swapper_spaces") {
......
} else if (symbol_exists("swapper_space") {
......
}
3. using my patch, it can fix output log of kmem -i which CACHED show
not right.
Fix before:
crash> kmem -i
PAGES TOTAL PERCENTAGE
TOTAL MEM 2854115 10.9 GB ----
FREE 169699 662.9 MB 5% of TOTAL MEM
USED 2684416 10.2 GB 94% of TOTAL MEM
SHARED 891094 3.4 GB 31% of TOTAL MEM
BUFFERS 329 1.3 MB 0% of TOTAL MEM
* CACHED 873327085626 3331478.4 GB 30598875% of TOTAL MEM*
SLAB 230128 898.9 MB 8% of TOTAL MEM
Fix after:
crash> kmem -i
PAGES TOTAL PERCENTAGE
TOTAL MEM 2854115 10.9 GB ----
FREE 169699 662.9 MB 5% of TOTAL MEM
USED 2684416 10.2 GB 94% of TOTAL MEM
SHARED 891094 3.4 GB 31% of TOTAL MEM
BUFFERS 329 1.3 MB 0% of TOTAL MEM
* CACHED 1729018 6.6 GB 60% of TOTAL MEM*
SLAB 230128 898.9 MB 8% of TOTAL MEM
I think crash tools without my patch, maybe miss some situation like
this which symbol miss in kenrel vmlinux.
I think that using both branch of symbol_exist("nr_swapper_spaces")
and symbol_exists("swapper_spaces") means to double check
the situation of all kinds of kernel and vmlinux.
It seen that bring my patch can deal with more unusual situation and
make crash tool more compatible.
Thanks！
Best Regards
------------------------------------------------------------------------
*From:* HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx>
*Sent:* Friday, December 1, 2023 3:08:03 PM
*To:* 薛国伦; devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx
*Cc:* Lianbo Jiang
*Subject:* Re: [External Mail]Re: [BUG FIXED]fix bug
of CACHED in kmem -i show memory
[外部邮件]
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On 2023/11/30 22:05, 薛国伦 wrote:
> Hi kazu:
>
>
> 1. I found that vmlinux of kernel-6.1 did not have symbol
nr_swapper_spaces but only have swapper_spaces
>
> Also check in GKI vmlinux, can not find nr_swapper_spaces
Hmm, upstream kernel 6.1 has it.
$ git show v6.1:mm/swap_state.c
struct address_space *swapper_spaces[MAX_SWAPFILES] __read_mostly;
static unsigned int nr_swapper_spaces[MAX_SWAPFILES] __read_mostly;
>
> It may have some problem in symbol of nr_swapper_spaces
>
>
> 2. I think that crash tools will check nr_swapper_spaces first and
then check *swapper_spaces, swaper_space[] last.
>
> so first check nr_swapper_spaces not found, crash tool can use
*swapper_spaces to enhance compatibility.
>
> The patch i send can resolve this situation which nr_swapper_spaces
symbols can not found.
But I cannot determine whether your patch is correct and should be
applied, without kernel patches or the cause of no nr_swapper_spaces.
Could you please find the information (e.g. links) of the related kernel
patches?
Thanks,
Kazu
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