Messages in this thread | | | Date | Thu, 17 Jun 2021 12:02:31 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH v7 5/5] printk: index: Add indexing support to dev_printk |
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On Tue 2021-06-15 17:52:56, Chris Down wrote: > While for most kinds of issues we have counters, tracepoints, or metrics > with a stable interface which can reliably be used to indicate issues, > in order to react to production issues quickly we sometimes need to work > with the interface which most kernel developers naturally use when > developing: printk, and printk-esques like dev_printk. > > dev_printk is by far the most likely custom subsystem printk to benefit > from the printk indexing infrastructure, since niche device issues > brought about by production changes, firmware upgrades, and the like are > one of the most common things that we need printk infrastructure's > assistance to monitor. > > Often these errors were never expected to practically manifest in > reality, and exhibit in code without extensive (or any) metrics present. > As such, there are typically very few options for issue detection > available to those with large fleets at the time the incident happens, > and we thus benefit strongly from monitoring netconsole in these > instances. > > As such, add the infrastructure for dev_printk to be indexed in the > printk index. Even on a minimal kernel config, the coverage of the base > kernel's printk index is significantly improved: > > Before: > > [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux > 4497 /sys/kernel/debug/printk/index/vmlinux > > After: > > [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux > 5573 /sys/kernel/debug/printk/index/vmlinux > > In terms of implementation, in order to trivially disambiguate them, > dev_printk is now a macro which wraps _dev_printk. > > Signed-off-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com>
Best Regards, Petr
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