linux 内核修改分辨率后出现的WARNING解决方法

我不是女神ヾ 2022-08-07 11:43 187阅读 0赞

将分辨率由800x480改为1280x800后 出现了如下警告

\[   21.581886\] ------------\[ cut here \]------------  
\[   21.581907\] WARNING: at mm/page\_alloc.c:2121 \_\_alloc\_pages\_nodemask+0x468/0x63c()  
\[   21.581914\] Modules linked in:  
\[   21.581940\] \[<c0040b28>\] (unwind\_backtrace+0x0/0xfc) from \[<c005aed4>\] (warn\_slowpath\_common+0x54/0x64)  
\[   21.581957\] \[<c005aed4>\] (warn\_slowpath\_common+0x54/0x64) from \[<c005af00>\] (warn\_slowpath\_null+0x1c/0x24)  
\[   21.581971\] \[<c005af00>\] (warn\_slowpath\_null+0x1c/0x24) from \[<c00a9d24>\] (\_\_alloc\_pages\_nodemask+0x468/0x63c)  
\[   21.581986\] \[<c00a9d24>\] (\_\_alloc\_pages\_nodemask+0x468/0x63c) from \[<c00419f8>\] (\_\_dma\_alloc+0x8c/0x3bc)  
\[   21.581999\] \[<c00419f8>\] (\_\_dma\_alloc+0x8c/0x3bc) from \[<c0041d4c>\] (dma\_alloc\_writecombine+0x24/0x2c)  
\[   21.582016\] \[<c0041d4c>\] (dma\_alloc\_writecombine+0x24/0x2c) from \[<c02791ec>\] (s3cfb\_map\_video\_memory+0xac/0x174)  
\[   21.582031\] \[<c02791ec>\] (s3cfb\_map\_video\_memory+0xac/0x174) from \[<c02799f4>\] (s3cfb\_set\_par+0x58/0xc0)  
\[   21.582050\] \[<c02799f4>\] (s3cfb\_set\_par+0x58/0xc0) from \[<c0271250>\] (fb\_set\_var+0x168/0x2a4)  
\[   21.582065\] \[<c0271250>\] (fb\_set\_var+0x168/0x2a4) from \[<c0271748>\] (do\_fb\_ioctl+0x3bc/0x5f4)  
\[   21.582079\] \[<c0271748>\] (do\_fb\_ioctl+0x3bc/0x5f4) from \[<c00e2aac>\] (do\_vfs\_ioctl+0x80/0x5fc)  
\[   21.582092\] \[<c00e2aac>\] (do\_vfs\_ioctl+0x80/0x5fc) from \[<c00e3060>\] (sys\_ioctl+0x38/0x60)  
\[   21.582108\] \[<c00e3060>\] (sys\_ioctl+0x38/0x60) from \[<c003ab00>\] (ret\_fast\_syscall+0x0/0x30)  
\[   21.582117\] ---\[ end trace d22d266c12264dc9 \]---

出现这个必不会影响显示　还是觉得不妥　以前也出现过这个问题也去管　这次就跟踪下吧

网上也有人碰过到这个问题网址:[http://comments.gmane.org/gmane.linux.ports.arm.kernel/115480][http_comments.gmane.org_gmane.linux.ports.arm.kernel_115480]

这里面给了个链接里有解决方法:[https://community.freescale.com/thread/320821][https_community.freescale.com_thread_320821]

不知道你们看不看的了　我把原文贴在下面

问题

Hello,
    
    I'm using dma_alloc_writecombine() to allocate memory in my framebuffer
    device driver just like many other drivers do.
    
    Now I have a new panel with a higher resolution and more bits-per-pixel.
    I want to use double-buffering with DirectFB and so my framebuffer size
    exceeds 4Mb.
    
    Even though my embedded system has plenty of memory, now I receive the
    following warning and the allocation fails:
    
    WARNING: at /home/teemhu/mcu/has/topas/mm/page_alloc.c:2012
    __alloc_pages_nodemask+0x444/0x650()
    
    This is due to the following check in __alloc_pages_slowpath():
    	if (order >= MAX_ORDER) {
    		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
    		return NULL;
    	}
    
    Because MAX_ORDER is 11, only memory chunks of size (PAGE_SIZE <<
    MAX_ORDER_NR_PAGES) = 4Mb can be allocated.
    
    Apparently this topic has come up when using the OMAP DSS already:
    http://www.spinics.net/lists/linux-omap/msg08124.html
    
    Another user has asked this question on the linuxfb-dev mailing list in
    October 2010, but did not receive an answer:
    http://www.spinics.net/lists/linux-fbdev/msg01745.html

出现这个问题的原因

DMA memory allocation is limited to 4MB

大小定义说明

#define CONFIG_FORCE_MAX_ZONEORDER 12
    
     
    
    By default, MAX_ORDER is 11 which means the biggest memory chunk is: PAGE_SIZE * 2 ^( FORCE_MAX_ZONEORDER - 1)
    
    = 4K * 1 K = 4M.

最后解决方法直接将

MAX_ORDER

改大

在头文件include/linux/mmzone.h里定义了MAX\_ORDER

首先确定下有没有定义FORCE\_MAX\_ZONEORDER

我的里面定义了FORCE\_MAX\_ZONEORDER但是make menuconfig里直接改不了FORCE\_MAX\_ZONEORDER在

arch/arm/Kconfig定义直接把default改成　然后make menuconfig保存　确认下.config这个参数是不是改了　编译下载

问题解决

[http_comments.gmane.org_gmane.linux.ports.arm.kernel_115480]: http://comments.gmane.org/gmane.linux.ports.arm.kernel/115480
[https_community.freescale.com_thread_320821]: https://community.freescale.com/thread/320821