HOW TO CHECK ASYNCHRONOUS I/O ON LINUX
<P>HOW TO CHECK ASYNCHRONOUS I/O ON LINUX </P><P> </P>
<P> </P>
<P><BR>修改时间07-MAY-2010 类型 HOWTO 状态 PUBLISHED<BR> </P>
<P>In this Document<BR> Goal<BR> Solution<BR> References</P>
<P><BR>Applies to:<BR>Oracle Server - Enterprise Edition - Version: 9.2.0.1 to 11.1.0.6 - Release: 9.2 to 11.1<BR>Linux x86<BR>***Checked for relevance on 07-May-2010***<BR>RedHat Linux 4 and above = kernel 2.4.x and above<BR>Oracle Enterprise Linux 4 and above = kernel 2.6.x and above <BR>Goal<BR>How to check if Asynchronous I/O is enabled on Linux Platform?<BR>Solution<BR>RHEL3 - kernel 2.4.x</P>
<P>output with async io enabled</P>
<P>$ cat /proc/slabinfo | grep kio<BR>kioctx 270 270 128 9 9 1 : 252 126<BR>kiocb 66080 66080 96 1652 1652 1 : 252 126<BR>kiobuf 236 236 64 4 4 1 : 252 126<BR>$</P>
<P><BR>RHEL4, OEL4 and above - kernel 2.6.x</P>
<P>output with async io enabled</P>
<P>$ cat /proc/slabinfo | grep kio<BR>kioctx 64 110 384 10 1 : tunables 54 27 8 : slabdata 11 11 0<BR>kiocb 13 315 256 15 1 : tunables 120 60 8 : slabdata 21 21 44<BR>$</P>
<P><BR>Why kiobuf is not displayed in RHEL4, OEL4 and above?</P>
<P>- The kiobuf is only relevant in the 2.4 generations of the kernel</P>
<P>- The kiobuf abstraction was introduced in 2.3 as a low-level way of representing I/O buffers. Its primary use, perhaps, was to represent zero-copy I/O operations going directly to or from user space. A number of problems were found with the kiobuf interface, however; among other things, it forced large I/O operations to be broken down into small chunks, and it was seen as a heavyweight data structure. So, in 2.5.43, kiobufs were removed from the kernel.</P>
<P>References<BR>NOTE:237299.1- How To Check if Asynchronous I/O is Working On Linux</P>
<P> 相关的</P>
<P><BR>产品</P>
<P>Oracle Database Products > Oracle Database > Oracle Database > Oracle Server - Enterprise Edition</P>
<P> </P>
<DIV></DIV>
页:
[1]