On Thu, Sep 01, 2022 at 10:05:03AM +0200, David Hildenbrand wrote: > On 31.08.22 21:01, Kent Overstreet wrote: > > On Wed, Aug 31, 2022 at 12:47:32PM +0200, Michal Hocko wrote: > >> On Wed 31-08-22 11:19:48, Mel Gorman wrote: > >>> Whatever asking for an explanation as to why equivalent functionality > >>> cannot not be created from ftrace/kprobe/eBPF/whatever is reasonable. > >> > >> Fully agreed and this is especially true for a change this size > >> 77 files changed, 3406 insertions(+), 703 deletions(-) > > > > In the case of memory allocation accounting, you flat cannot do this with ftrace > > - you could maybe do a janky version that isn't fully accurate, much slower, > > more complicated for the developer to understand and debug and more complicated > > for the end user. > > > > But please, I invite anyone who's actually been doing this with ftrace to > > demonstrate otherwise. > > > > Ftrace just isn't the right tool for the job here - we're talking about adding > > per callsite accounting to some of the fastest fast paths in the kernel. > > > > And the size of the changes for memory allocation accounting are much more > > reasonable: > > 33 files changed, 623 insertions(+), 99 deletions(-) > > > > The code tagging library should exist anyways, it's been open coded half a dozen > > times in the kernel already. > > Hi Kent, > > independent of the other discussions, if it's open coded already, does > it make sense to factor that already-open-coded part out independently > of the remainder of the full series here? It's discussed in the cover letter, that is exactly how the patch series is structured. > [I didn't immediately spot if this series also attempts already to > replace that open-coded part] Uh huh. Honestly, some days it feels like lkml is just as bad as slashdot, with people wanting to get in their two cents without actually reading...