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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/"><channel><title>Rob's Groups Activities</title><link>https://community.arm.com/members/roz</link><description>Recent activity for people in Rob's group</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>Ask A Question I</title><link>https://community.arm.com/achievements/460ac7df-7ccc-4c42-a204-9e05eef3be09</link><pubDate>Wed, 11 Nov 2020 00:02:36 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:76b56120-7559-4973-b929-e1b822a9f010</guid><dc:creator /><description>Ask a question in a forum.</description></item><item><title>Not enough memory in noMMU UcLinux on STM32f769</title><link>https://community.arm.com/developer/ip-products/system/f/embedded-forum/48025/not-enough-memory-in-nommu-uclinux-on-stm32f769</link><pubDate>Wed, 11 Nov 2020 00:02:34 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:47e879e2-4e99-4fb4-b4e9-1d4e10fa10a7</guid><dc:creator>Rob</dc:creator><description>&lt;p&gt;Hello,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;I&amp;#39;m trying to run noMMU UcLinux buildroot based distribution on STM32F769 (cortex m7) platform with 16MB of RAM.&lt;/p&gt;
&lt;p&gt;It seems that at the end, there is over 4MB of free memory but it seems like grouped in a lot of smaller chunks instead of few bigger.&lt;/p&gt;
&lt;p&gt;When I run some bigger compiled binaries in flat format, I get segfaults, because memory cannot be allocated to start the app.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;I&amp;#39;m getting similar errors on strace, openssl, mosquito, (and it seems on any bigger app):&lt;/p&gt;
&lt;p&gt;&lt;pre class="ui-code" data-mode="text"&gt;nommu: Allocation of length 1728512 from process 60 (openssl) failed
active_anon:0 inactive_anon:0 isolated_anon:0
active_file:3 inactive_file:11 isolated_file:0
unevictable:202 dirty:0 writeback:0 unstable:0
slab_reclaimable:0 slab_unreclaimable:805
mapped:0 shmem:0 pagetables:0 bounce:0
free:1154 free_pcp:0 free_cma:0
Node 0 active_anon:0kB inactive_anon:0kB active_file:12kB inactive_file:44kB unevictable:808kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no
Normal free:4616kB min:432kB low:540kB high:648kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:12kB inactive_file:44kB unevictable:808kB writepending:0kB present:15296kB managed:11864kB mlocked:0kB kernel_stack:264kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
lowmem_reserve[]: 0 0
Normal: 18*4kB (UM) 20*8kB (UM) 10*16kB (UM) 10*32kB (UM) 13*64kB (UM) 8*128kB (UM) 4*256kB (UM) 2*512kB (M) 0*1024kB 0*2048kB 0*4096kB = 4616kB
216 total pagecache pages
binfmt_flat: Unable to allocate RAM for process text/data, errno –12
&lt;/pre&gt;&lt;/p&gt;
&lt;p&gt;I&amp;#39;m not sure if I understand right, but last line explains allocation possibilities available.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;pre class="ui-code" data-mode="text"&gt;Normal: 18*4kB (UM) 20*8kB (UM) 10*16kB (UM) 10*32kB (UM) 13*64kB (UM) 8*128kB (UM) 4*256kB (UM) 2*512kB (M) 0*1024kB 0*2048kB 0*4096kB = 4616kB
&lt;/pre&gt;&lt;/p&gt;
&lt;p&gt;It seems that there is enough memory, but I don&amp;#39;t understand why it is&amp;nbsp; so fragmented and grouped in many smaller chunks.&lt;/p&gt;
&lt;p&gt;Does this come as a consequence of memory fragmentation and cannot be improved ?&lt;/p&gt;
&lt;p&gt;Or is there any possibility to get bigger available chunks of memory, so my binary will be able to come into memory to execute without segfaults ? I remember that older kernels had BIGALLOCS config option, but it seems not present anymore.&lt;/p&gt;
&lt;p&gt;Any advice, experience, examples or docs to learn from ?&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks in advance,&lt;/p&gt;
&lt;p&gt;regards,&lt;/p&gt;
&lt;p&gt;Rob.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>