Hi Anatoly, In my test for DPDK 18.11, I notice the following:
1. Using --legacy-mem switch, DPDK still opens 1 fd/huge page. In essence, it is the same with or without this switch. 2. Using --single-file-segments does reduce the open fd to 1. However, for each huge page that is in-use, a .lock file is opened. As a result, it still uses up a large number of fd's. Thanks. -- edwin -----Original Message----- From: Iain Barker Sent: Wednesday, February 27, 2019 8:57 AM To: Burakov, Anatoly <anatoly.bura...@intel.com>; Wiles, Keith <keith.wi...@intel.com> Cc: dev@dpdk.org; Edwin Leung <edwin.le...@oracle.com> Subject: RE: [dpdk-dev] Question about DPDK hugepage fd change Original Message from: Burakov, Anatoly [mailto:anatoly.bura...@intel.com] >I just realized that, unless you're using --legacy-mem switch, one >other way to alleviate the issue would be to use --single-file-segments >option. This will still store the fd's, however it will only do so per >memseg list, not per page. So, instead of 1000's of fd's with 2MB >pages, you'd end up with under 10. Hope this helps! Hi Anatoly, Thanks for the update and suggestion. We did try using --single-file-segments previously. Although it lowers the amount of fd's allocated for tracking the segments as you noted, there is still a problem. It seems that a .lock file is created for each huge page, not for each segment. So with 2MB pages the glibc limit of 1024 fd's is still exhausted quickly if there is ~2GB of 2MB huge pages. Edwin can provide more details from his testing. In our case much sooner, as we already use >500 fd's for the application, just 1GB of 2MB huge pages is enough to hit the fd limit due to the .lock files. Thanks.
