{"id":3238,"date":"2017-03-03T00:01:09","date_gmt":"2017-03-02T16:01:09","guid":{"rendered":"https:\/\/ixyzero.com\/blog\/?p=3238"},"modified":"2017-03-03T00:01:09","modified_gmt":"2017-03-02T16:01:09","slug":"%e5%a6%82%e4%bd%95%e5%87%8f%e5%b0%91inode%e5%92%8cdentry%e7%9a%84%e7%bc%93%e5%ad%98%e4%bb%a5%e5%b0%bd%e9%87%8f%e9%81%bf%e5%85%8doom","status":"publish","type":"post","link":"https:\/\/ixyzero.com\/blog\/archives\/3238.html","title":{"rendered":"\u5982\u4f55\u51cf\u5c11inode\u548cdentry\u7684\u7f13\u5b58\u4ee5\u5c3d\u91cf\u907f\u514dOOM"},"content":{"rendered":"

=Start=<\/p>\n

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\u5728\u670d\u52a1\u5668\u4e0a\u6267\u884c\u67d0\u4e2afind\u64cd\u4f5c\u65f6\uff0c\u5bfc\u81f4\u5185\u5b58\u5360\u7528\u5347\u9ad8\uff0c\u4e1a\u52a1\u8fdb\u7a0b\u7684\u5185\u5b58\u5360\u7528\u4e5f\u6301\u7eed\u5347\u9ad8\u4e14\u6062\u590d\u7f13\u6162\uff0c\u521d\u6b65\u6392\u67e5\u770b\u4e0a\u53bb\u50cf\u662f\u56e0\u4e3aproc_inode_cache\u7684\u5360\u7528\u5347\u9ad8\u5bfc\u81f4\u3002<\/p>\n

\u6b63\u6587\uff1a<\/h4>\n

\u53c2\u8003\u89e3\u7b54\uff1a<\/h5>\n

\u901a\u8fc7\u5b66\u4e60 [Linux Used\u5185\u5b58\u5230\u5e95\u54ea\u91cc\u53bb\u4e86\uff1f |\u00a0http:\/\/blog.yufeng.info\/archives\/2456<\/a>] \u4e86\u89e3\u5230\u300c\u5185\u5b58\u7684\u53bb\u5411\u4e3b\u8981\u67093\u4e2a\uff1a1.\u8fdb\u7a0b\u6d88\u8017\uff1b2.slab\u6d88\u8017\uff1b3.pagetable\u6d88\u8017\u3002\u300d<\/p>\n

struct page\u662f\u7cfb\u7edfboot\u7684\u65f6\u5019\u5c31\u4f1a\u6839\u636e\u5185\u5b58\u5927\u5c0f\u7b97\u51fa\u6765\u5206\u914d\u51fa\u53bb\u7684\uff0c18\u5185\u6838\u662f1.56%\u5de6\u53f3\uff0c32\u5185\u6838\u7531\u4e8ecgroup\u7684\u539f\u56e0\u4f1a\u57282.3%<\/p><\/blockquote>\n

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\u67e5\u770bslab\u4f7f\u7528\u60c5\u51b5\u7684\u65b9\u6cd5<\/b><\/div>\n
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$ slabtop<\/code><\/div>\n
[OR]<\/code><\/div>\n
$ cat \/proc\/slabinfo |awk\u00a0<\/code>'{print $1,$3*$4\/1024,\"KB\"}'<\/code>\u00a0| sort -k2 -n | tail\u00a0<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n

&<\/p>\n

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\u6bd4\u8f83\u5371\u9669\u7684\u505a\u6cd5<\/b><\/div>\n
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echo\u00a0<\/code>1<\/code>\u00a0> \/proc\/sys\/vm\/drop_caches\u00a0 # free pagecache<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>[OR]<\/code><\/div>\n
echo\u00a0<\/code>2<\/code>\u00a0> \/proc\/sys\/vm\/drop_caches\u00a0 # free dentries and inodes<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>[OR]<\/code><\/div>\n
echo\u00a0<\/code>3<\/code>\u00a0> \/proc\/sys\/vm\/drop_caches\u00a0 # free pagecache, dentries and inodes<\/code><\/div>\n
sync\u00a0 # forces the dump to be destructive<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n

&<\/p>\n

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\u6e29\u548c\u4e00\u70b9\u7684\u505a\u6cd5<\/b><\/div>\n
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echo\u00a0<\/code>300<\/code>\u00a0> \/proc\/sys\/vm\/vfs_cache_pressure\u00a0 # Increasing vfs_cache_pressure beyond\u00a0<\/code>100<\/code>\u00a0causes the kernel to prefer to reclaim dentries and inodes<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n
\u53c2\u8003\u94fe\u63a5\uff1a<\/h5>\n