/dev/hdaµÄdmaģʽÎÞ·¨´ò¿ª£¬umda4ÎÞ·¨´ò¿ª¡£ ÔÚ·¢Ðаæ×Ô´øµÄºËÐÄÏ£¬dma¿ÉÒÔ´ò¿ª£¬udma4¿ÉÒÔ´ò¿ª¡£ ÇëÎÊÄں˱àÒëʱÄÇЩѡÏîÊǺÍÓ²ÅÌÏà¹ØµÄ¡£
scatter/gather·½Ê½ÊÇÓëblock dma·½Ê½Ïà¶ÔÓ¦µÄÒ»ÖÖdma·½Ê½¡£ ÔÚdma´«ÊäÊý¾ÝµÄ¹ý³ÌÖУ¬ÒªÇóÔ´ÎïÀíµØÖ·ºÍÄ¿±êÎïÀíµØÖ·±ØÐëÊÇÁ¬ÐøµÄ¡£µ«ÔÚÓеļÆËã»úÌåϵÖУ¬ÈçIA£¬Á¬ÐøµÄ´æ´¢Æ÷µØÖ·ÔÚÎïÀíÉϲ»Ò»¶¨ÊÇÁ¬ÐøµÄ£¬Ôòdma´«ÊäÒª·Ö³É¶à´ÎÍê³É¡£ Èç¹û´«ÊäÍêÒ»¿éÎïÀíÁ¬ÐøµÄÊý¾Ýºó·¢ÆðÒ»´ÎÖжϣ¬Í¬Ê±Ö÷»ú½øÐÐÏÂÒ»¿éÎïÀíÁ¬ÐøµÄ´«Ê䣬ÔòÕâÖÖ·½Ê½¼´Îªblock dma·½Ê½¡£ scatter/gather·½Ê½Ôò²»Í¬£¬ËûÊÇÓÃÒ»¸öÁ´±íÃèÊöÎïÀí²»Á¬ÐøµÄ´æ´¢Æ÷£¬È»ºó°ÑÁ´...
ʲôÊÇdma£¿ µ±ÎÒÃÇÏò¼ÆËã»úÖмÓÈëÁËÒ»¿éеÄÉù¿¨»òÆäËüÊÊÅ俨ʱ£¬°²×°³ÌÐò¿ÉÄÜ»áÌáÐÑÎÒÃÇÓ¦¸ÃÑ¡ÔñÒ»¸ödmaͨµÀ¡£ÄÇdmaÊÇÊ²Ã´ÄØ? dma£¨Direct Memory Access£©£¬¼´Ö±½Ó´æ´¢Æ÷´æÈ¡£¬ÊÇÒ»ÖÖ¿ìËÙ´«ËÍÊý¾ÝµÄ»úÖÆ¡£Êý¾Ý´«µÝ¿ÉÒÔ´ÓÊÊÅ俨µ½Äڴ棬´ÓÄÚ´æµ½ÊÊÅ俨»ò´ÓÒ»¶ÎÄÚ´æµ½ÁíÒ»¶ÎÄÚ´æ¡£dma¼¼ÊõµÄÖØÒª ÐÔÔÚÓÚ£¬ÀûÓÃËü½øÐÐÊý¾Ý´«ËÍʱ²»ÐèÒªCPUµÄ²ÎÓ롣ÿ̨µçÄÔÖ÷»ú°åÉ϶¼ÓÐdma¿ØÖÆÆ÷£¬Í¨³£¼ÆËã»ú¶ÔÆä±à³Ì£¬²¢ÓÃÒ»¸öÊÊÅäÆ÷ÉϵÄROM(ÈçÈíÅÌ...
×òÍí¿ªÊ¼»ú·¿bsd62Á¬²»Í¨,ÖÐÎç½øÈ¥Ò»¿´,ÂúÆÁµÄ¹ØÓÚ/dev/ad3 read_dmaµÄÐÅÏ¢. ÖØÆôfsck -yºóÕý³£Æô¶¯,ÏÂÃæÊǹØÓÚsmartctlµÄÐÅÏ¢,ÊDz»ÊÇÓ²ÅÌÓÐÎÊÌâÄØ? **** bsd62# smartctl -H /dev/ad3 smartctl version 5.36 [i386-portbld-freebsd6.2] Copyright (C) 2002-6 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: P...
µÚ9Õ ¡¡dma 9.1 dma£ºÊ²Ã´ÊÇdma£¬ËüÈçºÎ¹¤×÷ Copyright © 1995,1997 Frank Durda IV , All Rights Reserved. 10 December 1996. Last Update 8 October 1997. ·Òë gvim ÔÎÄÁ¬½Ó http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/dma.html Ö±½ÓÄÚ´æ·ÃÎÊ(dma)ÊÇÒ»ÖÖ´«ÊäÊý¾ÝµÄ·½Ê½£¬ËüÔÊÐíÁ½¸öµØÖ·ÉϵÄÊý¾ÝÖ±½Ó½øÐд«Êä¶øÎÞÐèCPUµÄ½éÈë¡£ dma¹¦ÄÜÔÚ²»Í¬¼ÆËã»úÌåϵϵÄʵÏÖ·½Ê½ÓÐËù²»Í¬£¬Òò´Ë...
ÏÂÃæµÄÕâ¶Î»°Õª×Ô»¥ÁªÍøÉÏ,ÎҸ㲻¶®"ʵ¼ÊµÄ´«ÊäÒ²²»½èÖúÂýËÙµÄISA dmaCÀ´½øÐÐ,¶øÊÇÓÉÄÚǶÔÚPCI¿¨ÖеÄdmaµç·£¨±È´«Í³µÄISA dmaCÒª¿ì£©À´Íê³É"Õâ¾ä»°µÄÒâ˼,ÄѵÀÊÇ˵ÿ¸öPCI¿¨É϶¼ÓÐÒ»¸ödmaC? dmaÊÇÍâÉèÓëÖ÷´æÖ®¼äµÄÒ»ÖÖÊý¾Ý´«Êä»úÖÆ¡£Ò»°ãÀ´Ëµ£¬ÍâÉèÓëÖ÷´æÖ®¼ä´æÔÚÁ½ÖÖÊý¾Ý´«Êä·½·¨£º£¨1£©Pragrammed I/O£¨PIO£©·½·¨£¬Ò²¼´ÓÉCPUͨ¹ýÄÚ´æ¶ÁдָÁî»òI/OÖ¸ÁîÀ´³ÖÐøµØ¶ÁдÍâÉèµÄÄÚ´æµ¥Ôª£¨8λ¡¢16λ»ò32룩£¬Ö±µ½Õû¸öÊý¾Ý´«Êä¹ý³ÌÍê³É...
ÔÚÇý¶¯Àï×öÒ»´ÎÓ²ÅÌdma²Ù×÷,ûÓÐÖжϲúÉú, ×ÜÊdz¬Ê±. ÄÄλ¸øµã½¨Òé, ¿´¿´ÎÒÒÅ©ÁËʲô²½Öè? ÎҵĹý³Ì´ó¸ÅÈçÏÂ. ¶ÁÃüÁî: ×¼±¸s/g table, °Ñs/g table µØÖ·Ð´Èës/gÖ¸Õë¼Ä´æÆ÷ дLBA & command register Çå³ýÖжÏ/´íÎó¼Ä´æÆ÷ È·¶¨¶Áд·½Ïò, ²¢Æô¶¯dma ÒÔÉϼ¸¸ö²½Öè, ÎÒ·´¸´È·ÈϹý, ¿´²»³öÓдíÎó. ´úÂëÓе㳤(>1000lines), Ë¡²»Ìù³öÀ´ÁË. ÔÚ³¬Ê±´¦Àíº¯ÊýÀï, ¶Á״̬¼Ä´æÆ÷, ·¢ÏÖdma²Ù×÷²¢Ã»ÓÐÍê³É. ¸÷λ¸øµã½¨Òé,ÏÈл¹ýÁË
os redhat 7.3 ³öÏÖÁËÏÂÁдíÎó£¬ÇëÎÊ¿ÉÄÜÊÇʲôÔÒòÔì³ÉµÄ£¬Ð»Ð»´ó¼Ò dma_timer_expiry: dma status == 0x20
ÊäÈë# hdparm -d1 /dev/hdaºóÏÔʾ /dev/hda: setting using_dma to 1 (on) HDIO_SET_dma failed: Operation not permitted using_dma = 0 (off) ÇëÎÊÔõô°ì?