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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@lists.crash-utility.osci.io
> *Cc:* Lianbo Jiang
> *Subject:* Re: [External Mail]Re: [Crash-utility] [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@nec.com>
> *Sent:* Friday, December 1, 2023 3:08:03 PM
> *To:* 薛国伦; devel@lists.crash-utility.osci.io
> *Cc:* Lianbo Jiang
> *Subject:* Re: [External Mail]Re: [Crash-utility] [BUG FIXED]fix bug
> of CACHED in kmem -i show memory
> [外部邮件]
> 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈
>
> 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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