>>> Lee Duncan <[email protected]> schrieb am 18.11.2014 um 22:35 in Nachricht <[email protected]>: > The following patch fixes a problem where the CPU becomes compute bound > when rediscovering targets, when there are hundreds of sessions. > > When his occurs, most of the time is spent in the function > iscsi_sysfs_for_each_session(). This function does a scandir(), > sorted alphabetically, to get a list of sessions, then scans > that list looking for a match. When there are hundreds of sesions > this can take forever.
I wonder: What takes forever: reading hundreds of sysfs entries, sorting them, or looking for a match? I guess none of them should take forever unless the algorithm is really very bad. > > This patch saves the current session and then ensures that this > session sorted to the front of the list. Testing shows that > CPU usage goes from near 100% to near 0% when running cable > plug tests with hundreds of sessions. > > Signed-off-by: Lee Duncan <[email protected]> > > -- > You received this message because you are subscribed to the Google Groups > "open-iscsi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/open-iscsi. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
