Hi Trond / Anna, I apologize for disturbing you, as I understand that you may be occupied with other tasks. However, I wanted to bring to your attention that several users have reported a performance issue, and are eagerly awaiting a possible solution. I have proposed a potential solution and I would be grateful if you could provide me with some feedback. Your input would be highly appreciated, as it will allow me to continue working on this issue and finding a resolution for our users. Thank you for your time and consideration. Best regards, Chengen Du On Wed, Mar 29, 2023 at 1:48 PM Chengen Du <chengen.du@xxxxxxxxxxxxx> wrote: > > Hi Trond / Anna, > > I wanted to provide you with additional feedback regarding the > performance issue that was addressed in commit 21fd9e8700de (NFS: > Correct timing for assigning access cache timestamp). > I apologize for reaching out to you frequently, but I believe this > information is important to share. > > Although the commit appears to have resolved the issue, I have > received reports from some community users who are experiencing a > significant increase in NFS ACCESS operations. > If you are interested, you can find further details regarding this > feedback here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2009325 > > After conducting a survey, I have discovered that this issue may be > attributed to suexec-like mechanisms. > Specifically, applications or users may use the 'su' command to switch > to other privileged users and operate on NFS-mounted folders. > In these instances, the login time will be renewed, and NFS ACCESS > operations will need to be resent. > > While I believe the new mechanism adheres to POSIX design and the > performance overhead seems reasonable, > I think it would be beneficial to provide a mount option that allows > users to decide whether to renew access cache after login. > In some production environments where access cache can be trusted due > to the stable group membership, this option could be particularly > useful. > > In my humble opinion, the option could be enabled by default for most > personal users who can afford the overhead. > However, I am open to hearing your thoughts on this approach or any > alternative ideas you may have. > I would be willing to contribute to this effort if there is an opportunity. > > Thank you for your time and consideration. > > Best regards, > Chengen Du
