Hi Chongyun, On Thu, 2019-09-05 at 02:58 +0000, Chongyun Wu wrote: > Hi Martin, Ben and other viewers > > Cloud you help to view below patch which try to deal with a multipath > active paths > count not right issue, thanks a lot. > > From deee7196ece43b01b8ee635e60ce465080905b5e Mon Sep 17 00:00:00 > 2001 > From: Chongyun Wu <wu.chongyun@xxxxxxx> > Date: Tue, 27 Aug 2019 13:58:33 +0800 > Subject: [PATCH] libmultipath: multipath active paths count > optimization > > Really count multipath active paths not use mpp->nr_active++ > or mpp->nr_active--, because there are other places might call > pathinfo to change path state not only in check_path, if other > places detect and changed path state but not do mpp->nr_active++ > or mpp->nr_active--, the active paths might not right any more. > > We meet an issue which actually have three paths but after all > paths down syslog report have three paths remaining so multipathd > not send disable queueing to dm and this dm device been blocked. > This patch might fix this issue. > > Signed-off-by: Chongyun Wu <wu.chongyun@xxxxxxx> > --- > libmultipath/structs_vec.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) Thanks a lot for your patch. We've discussed this previously, and in general, there's little reason not to do it - pathcount() is fast, and could be made even faster. But if we do, we should ditch the nr_active field altogether - no need to carry it around if we re-calculate it anyway when we need it. However, it worries me a bit that nr_active may go wrong. Both Ben and I have reviewed the code and we thought the nr_active tracking was correct. Something seems to happen in our code that we don't understand. - can you please confirm that you are using the latest code, containing e224d57 "libmutipath: continue to use old state on PATH_PENDING", 9b715bf "multipathd: Fix miscounting active paths" and (in case you're using the marginal_paths options) also 7d4b40f and 058df77 ? - If you have a reliable reproducer, would you mind adding log messages to the code you just submitted, so that we can observe how nr_active evolves in time, and perhaps understand why it's going wrong? Regards Martin -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
