On Wed, Jan 20, 2016 at 11:59:09AM -0600, Eric Sandeen wrote: > I had a request for the kmem_alloc deadlock warning to print the > filesystem involved. > > Any objections to passing mp into kmem_alloc() and friends whenever > it's reasonably available from the caller? > > It'd be a big mechanical change, don't want to embark on that unless > it seems acceptable & useful. I think I hinted at this in the configurable error handling patchset I have so that we could have configurable ENOMEM error handling. My comment in the current commit message for that patch includes this: | I'm not yet sure how to hook it into the memory allocation calls - | that will be done in a later patch; this just demonstrates how | multiple classes are configured and initialised. It may be that we | don't configure specific errors here - instead configure how we | handle specific types of allocation failure e.g. GFP_KERNEL vs | GFP_NOFS vs allocations inside transactions. Either way, we are | going to need to plumb the error config handler into the | memory allocation code in some manner. So I think we are going to have to plumb the xfs_mount into these calls at some point in the near future. > I think we generally know the root causes of the most common deadlock > warnings, but it's a warm fuzzy to give as much info as possible. > > Heck, I almost wonder if passing a descriptive string in, for at > least the problematic cases we know about, i.e. "extent map realloc" > so we'd get something like: > > XFS (sdb1): myprocess(123) possible memory allocation deadlock size 12345 during extent map realloc in kmem_alloc (mode:0x250) If we want more context, then make it an error message that can dump the stack when the error level is turned up. i.e. if we pass in an xfs_mount, we can use XFS_ERROR_REPORT here... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
