Re: [PATCH] selftests/bpf: Remove duplicate copies of the arena spinlock qnodes
"Kumar Kartikeya Dwivedi" <[email protected]>
| Newsgroups | org.kernel.vger.linux-kselftest,dev.linux.lists.sched-ext,org.kernel.vger.bpf,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Mon Aug 17, 2026 at 7:14 PM CEST, Emil Tsalapatis wrote: > On Mon, Aug 17, 2026 at 9:02 AM Changwoo Min <[email protected]> wrote: >> >> > >> Hi Daniel, >> >> On 8/17/26 6:05 PM, Daniel Borkmann wrote: >> > On 8/3/26 2:18 AM, Changwoo Min wrote: >> >> bpf_arena_spin_lock.h defines its 64KB qnodes array in the header, so >> >> every translation unit including it emits a copy. __weak makes them all >> >> resolve to one instance, but bpftool gen object merges only the symbols >> >> and concatenates each input's .addr_space.1 bytes, leaving the surplus >> >> copies unreferenced in the linked object. >> >> >> >> libarena links ten such units, so nine copies were dead weight (bytes): >> >> >> >> object before after >> >> ----------------------------------------------------- >> >> .addr_space.1 in libarena.bpf.o 676200 86376 >> >> libarena.skel.h 2100123 892371 >> >> libarena_asan.skel.h 2641124 1466477 >> >> >> >> Declare qnodes in the header and let each program define it once: >> >> libarena in src/common.bpf.c, and the arena_spin_lock test beside the >> >> lock it guards. >> >> >> >> Tested with test_progs -t arena_spin_lock and -t libarena. >> >> >> >> Signed-off-by: Changwoo Min <[email protected]> > > Hi Changwoo, > > Sorry for the late reply, for the next version feel free to add: > > Reviewed-by: Emil Tsalapatis <[email protected]> > Added the tag to v2 and applied, thanks. >> > This doesn't apply cleanly, could you respin against latest bpf-next? >> >> Sure. I will send the v2 rebased on the HEAD of the the bpf-next tree soon. >> >> Regards. >> Changwoo Min >> >> > >> > Thanks, >> > Daniel >> > >> >>