On Thu, Apr 27 2017 at 1:11P -0400, Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > When debugging the dm-mpath driver it is important to know what > decisions have been taken with regard to requeuing. Hence this > patch that adds pr_debug() statements that report what decisions > have been taken. > > Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx> > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> I've not used pr_debug() before.. I generally sprinkle debugging when I'm actively chasing an issue and then throw it away once I sort the problem out. Documentation/process/coding-style.rst says: "Coming up with good debugging messages can be quite a challenge; and once you have them, they can be a huge help for remote troubleshooting. However debug message printing is handled differently than printing other non-debug messages. While the other pr_XXX() functions print unconditionally, pr_debug() does not; it is compiled out by default, unless either DEBUG is defined or CONFIG_DYNAMIC_DEBUG is set." So I assume you're leveraging DYNAMIC_DEBUG. Anyway, I'm not liking the idea of making this debugging part of the mpath code. But if there is a convincing argument for it please elaborate. Are you finding that things are going wrong on production systems and enabling pr_debug() in these paths would have, or has, saved you? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
