Messages in this thread | | | Date | Thu, 03 Sep 2020 11:06:47 +0530 | From | Sai Prakash Ranjan <> | Subject | Re: [RFC PATCH 0/7] Trace events to pstore |
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On 2020-09-03 03:17, Joel Fernandes wrote: > On Wed, Sep 2, 2020 at 4:01 PM Nachammai Karuppiah > <nachukannan@gmail.com> wrote: >> >> Hi, >> >> This patch series adds support to store trace events in pstore. >> >> Storing trace entries in persistent RAM would help in understanding >> what >> happened just before the system went down. The trace events that led >> to the >> crash can be retrieved from the pstore after a warm reboot. This will >> help >> debug what happened before machine’s last breath. This has to be done >> in a >> scalable way so that tracing a live system does not impact the >> performance >> of the system. > > Just to add, Nachammai was my intern in the recent outreachy program > and we designed together a way for trace events to be written to > pstore backed memory directory instead of regular memory. The basic > idea is to allocate frace's ring buffer on pstore memory and have it > right there. Then recover it on reboot. Nachammai wrote the code with > some guidance :) . I talked to Steve as well in the past about the > basic of idea of this. Steve is on vacation this week though. > > This is similar to what +Sai Prakash Ranjan was trying to do sometime > ago: https://lkml.org/lkml/2018/9/8/221 . But that approach involved > higher overhead due to synchronization of writing to the otherwise > lockless ring buffer. > > +Brian Norris has also expressed interest for this feature. >
Great work Nachammai and Joel, I have few boards with warm reboot support and will test this series in coming days.
Thanks, Sai
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