my wordpress site showing Out of memory error frequently

I have a WordPress site which is frequently showing out of memory error

i have also increased memory in config file

define('WP_MEMORY_LIMIT', '384M');

My php info file showing :

PHP Version 5.4.36 memory_limit 512M post_max_size 8M upload_max_filesize 4M

my error_log file showing below info

[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 6029312) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/link-template.php on line 2533
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 8912896) (tried to allocate 78 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 1750
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 4718592) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/class-wp-theme.php on line 256
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 7340032) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/category-template.php on line 519
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 6291456) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 1029
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 7602176) (tried to allocate 13440 bytes) in xxxxxxxx/public_html/wp-includes/comment.php on line 788
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 8126464) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 2309
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 9961472) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 822
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 6553600) (tried to allocate 4480 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 3233
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 8912896) (tried to allocate 78 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 1750
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 2097152) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/default-filters.php on line 108
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 9437184) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-includes/script-loader.php on line 248
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 262144) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-load.php on line 56
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 262144) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-load.php on line 56
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 4718592) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/class-wp-theme.php on line 256
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 11272192) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/media.php on line 3020
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 11534336) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/class-http.php on line 1396
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 4456448) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/theme.php on line 591
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 14942208) (tried to allocate 1920 bytes) in xxxxxxxx/public_html/wp-content/plugins/wordpress-importer/wordpress-importer.php on line 420
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 10223616) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 2769
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 4980736) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/user.php on line 1149
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 12320768) (tried to allocate 87 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 1717
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 10223616) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 2769
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Out of memory (allocated 15990784) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-content/plugins/wp-postratings/postratings-stats.php on line 424
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Call to undefined function is_user_logged_in() in xxxxxxxx/public_html/wp-content/plugins/wp-fastest-cache/inc/cache.php on line 146
[05-Oct-2015 00:45:42 UTC] PHP Fatal error:  Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[05-Oct-2015 02:05:02 UTC] PHP Fatal error:  Out of memory (allocated 20447232) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-content/plugins/all-in-one-seo-pack/aioseop_utility.php on line 352
[05-Oct-2015 02:05:02 UTC] PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/local/lib/php/extensions/no-debug-non-zts-20100525/pdo_mysql.so' - /usr/local/lib/php/extensions/no-debug-non-zts-20100525/pdo_mysql.so: failed to map segment from shared object: Cannot allocate memory in Unknown on line 0
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 18874368) (tried to allocate 3840 bytes) in xxxxxxxx/public_html/wp-content/themes/hdwallpapers/functions.php on line 221
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 15466496) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-content/plugins/wp-postratings/wp-postratings.php on line 464
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 9961472) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 822
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 10747904) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/update.php on line 141
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Call to undefined function is_user_logged_in() in xxxxxxxx/public_html/wp-content/plugins/wp-fastest-cache/inc/cache.php on line 146
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 15990784) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-content/plugins/wp-postratings/postratings-stats.php on line 424
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Call to undefined function is_user_logged_in() in xxxxxxxx/public_html/wp-content/plugins/wp-fastest-cache/inc/cache.php on line 146
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 7602176) (tried to allocate 13440 bytes) in xxxxxxxx/public_html/wp-includes/comment.php on line 788
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 10223616) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 2769
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 18612224) (tried to allocate 32 bytes) in xxxxxxxx/public_html/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php on line 620
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 10747904) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/update.php on line 141
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 11796480) (tried to allocate 9600 bytes) in xxxxxxxx/public_html/wp-includes/class-http.php on line 1526
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 8912896) (tried to allocate 78 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 1750
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 14942208) (tried to allocate 1920 bytes) in xxxxxxxx/public_html/wp-content/plugins/wordpress-importer/wordpress-importer.php on line 420
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 10223616) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 2769
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 281
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 11796480) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/widgets.php on line 1391
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 13107200) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-content/plugins/ewww-image-optimizer/common.php on line 493
[05-Oct-2015 02:05:04 UTC] PHP Fatal error:  Out of memory (allocated 8650752) (tried to allocate 33280 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 733
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 8388608) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/feed.php on line 529
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 7602176) (tried to allocate 13440 bytes) in xxxxxxxx/public_html/wp-includes/comment.php on line 788
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 281
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 7077888) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/post-template.php on line 1600
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 8388608) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/feed.php on line 529
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 281
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 281
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 12582912) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-content/plugins/ewww-image-optimizer/ewww-image-optimizer.php on line 511
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 11010048) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-includes/canonical.php on line 264
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 6815744) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 4961
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 1835008) (tried to allocate 690 bytes) in xxxxxxxx/public_html/wp-includes/wp-db.php on line 2146
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 8912896) (tried to allocate 72 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 1750
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 12320768) (tried to allocate 72 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 1714
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 9175040) (tried to allocate 4480 bytes) in xxxxxxxx/public_html/wp-includes/deprecated.php on line 2223
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 9961472) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/taxonomy.php on line 822
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 8388608) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/feed.php on line 529
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 8126464) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 2309
[05-Oct-2015 02:09:36 UTC] PHP Fatal error:  Out of memory (allocated 6291456) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/post.php on line 993
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 2883584) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/formatting.php on line 183
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 3145728) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-includes/formatting.php on line 1158
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 4718592) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/class-wp-theme.php on line 256
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 5767168) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/link-template.php on line 141
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 4194304) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-includes/query.php on line 2794
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 3670016) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/capabilities.php on line 1235
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 3407872) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/formatting.php on line 3166
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 4980736) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/user.php on line 1300
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 2883584) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/formatting.php on line 183
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 8126464) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 2309
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 10747904) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/update.php on line 141
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 7077888) (tried to allocate 1280 bytes) in xxxxxxxx/public_html/wp-includes/post-template.php on line 1579
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 8650752) (tried to allocate 33280 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 733
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 11796480) (tried to allocate 8960 bytes) in xxxxxxxx/public_html/wp-includes/class-http.php on line 1518
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 8126464) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 2309
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 9699328) (tried to allocate 79360 bytes) in xxxxxxxx/public_html/wp-includes/script-loader.php on line 532
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 9437184) (tried to allocate 196608 bytes) in xxxxxxxx/public_html/wp-includes/script-loader.php on line 248
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 8126464) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 2309
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 7077888) (tried to allocate 1280 bytes) in xxxxxxxx/public_html/wp-includes/post-template.php on line 1579
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 8912896) (tried to allocate 72 bytes) in xxxxxxxx/public_html/wp-includes/kses.php on line 1750
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 3072 bytes) in xxxxxxxx/public_html/wp-includes/comment-template.php on line 244
[05-Oct-2015 03:16:57 UTC] PHP Fatal error:  Out of memory (allocated 6029312) (tried to allocate 1280 bytes) in xxxxxxxx/public_html/wp-includes/link-template.php on line 2524
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Out of memory (allocated 19660800) (tried to allocate 32 bytes) in xxxxxxxx/public_html/wp-includes/functions.php on line 1602
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Out of memory (allocated 18087936) (tried to allocate 640 bytes) in xxxxxxxx/public_html/wp-content/plugins/all-in-one-seo-pack/aioseop_module_class.php on line 597
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Out of memory (allocated 17825792) (tried to allocate 49152 bytes) in xxxxxxxx/public_html/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php on line 2863
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Out of memory (allocated 18612224) (tried to allocate 89 bytes) in xxxxxxxx/public_html/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php on line 612
[05-Oct-2015 03:16:58 UTC] PHP Fatal error:  Out of memory (allocated 19922944) (tried to allocate 12288 bytes) in xxxxxxxx/public_html/wp-includes/template-loader.php on line 48

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