linux-kernel - Re: [PATCH] crash_core: export vmemmap when CONFIG_SPARSEMEM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <33021b87-4c6a-45fc-a6ae-265765cfcd78@amperemail.onmicrosoft.com>
Date:   Mon, 27 Nov 2023 11:18:27 +0800
From:   Shijie Huang <shijie@...eremail.onmicrosoft.com>
To:     Baoquan He <bhe@...hat.com>,
        Huang Shijie <shijie@...amperecomputing.com>
Cc:     k-hagio-ab@....com, lijiang@...hat.com, akpm@...ux-foundation.org,
        vgoyal@...hat.com, dyoung@...hat.com, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org, patches@...erecomputing.com
Subject: Re: [PATCH] crash_core: export vmemmap when CONFIG_SPARSEMEM_VMEMMAP
 is enabled


在 2023/11/27 10:51, Baoquan He 写道:
> Hi,
>
> On 11/27/23 at 10:07am, Huang Shijie wrote:
>> In memory_model.h, if CONFIG_SPARSEMEM_VMEMMAP is configed,
>> kernel will use vmemmap to do the __pfn_to_page/page_to_pfn,
>> and kernel will not use the "classic sparse" to do the
>> __pfn_to_page/page_to_pfn.
>>
>> So export the vmemmap when CONFIG_SPARSEMEM_VMEMMAP is configed.
>> This makes the user applications (crash, etc) get faster
>> pfn_to_page/page_to_pfn operations too.
> Are there Crash or makedupfile patches posted yet to make use of this?

I have patches for Crash to use the 'vmemmap', but after this patch is 
merged, I will send it out.

(I think Kazu will not merge a crash patch which depends on a kernel 
patch which is not merged.)


Thanks

Huang Shijie


>> Signed-off-by: Huang Shijie <shijie@...amperecomputing.com>
>> ---
>>   kernel/crash_core.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>> index efe87d501c8c..9653c4177191 100644
>> --- a/kernel/crash_core.c
>> +++ b/kernel/crash_core.c
>> @@ -765,6 +765,9 @@ static int __init crash_save_vmcoreinfo_init(void)
>>   	VMCOREINFO_SYMBOL(mem_map);
>>   	VMCOREINFO_SYMBOL(contig_page_data);
>>   #endif
>> +#ifdef CONFIG_SPARSEMEM_VMEMMAP
>> +	VMCOREINFO_SYMBOL_ARRAY(vmemmap);
>> +#endif
>>   #ifdef CONFIG_SPARSEMEM
>>   	VMCOREINFO_SYMBOL_ARRAY(mem_section);
>>   	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
>> -- 
>> 2.40.1
>>