On lunedì 12 giugno 2023 12:33:41 CEST Sumitra Sharma wrote: > kmap() has been deprecated in favor of the kmap_local_page() > due to high cost, restricted mapping space, the overhead of > a global lock for synchronization, and making the process > sleep in the absence of free slots. > > kmap_local_page() is faster than kmap() and offers thread-local > and CPU-local mappings, take pagefaults in a local kmap region > and preserves preemption by saving the mappings of outgoing > tasks and restoring those of the incoming one during a context > switch. > > The mapping is kept thread local in the function > “generate_test_data” in test_bpf.c > > Therefore, replace kmap() with kmap_local_page() and use > memcpy_to_page() to avoid open coding kmap_local_page() > + memcpy() + kunmap_local(). > > Remove the unused variable “ptr”. Sumitra, Please Cc your mentors while in the internship. It's not mandatory but it would expedite comments and reviews :-) > > Signed-off-by: Sumitra Sharma <sumitraartsy@xxxxxxxxx> > --- > lib/test_bpf.c | 10 +--------- > 1 file changed, 1 insertion(+), 9 deletions(-) > > diff --git a/lib/test_bpf.c b/lib/test_bpf.c > index ade9ac672adb..3bb94727d83b 100644 > --- a/lib/test_bpf.c > +++ b/lib/test_bpf.c > @@ -14381,25 +14381,17 @@ static void *generate_test_data(struct bpf_test > *test, int sub) * single fragment to the skb, filled with > * test->frag_data. > */ > - void *ptr; > - > page = alloc_page(GFP_KERNEL); > > if (!page) > goto err_kfree_skb; > > - ptr = kmap(page); > - if (!ptr) > - goto err_free_page; > - memcpy(ptr, test->frag_data, MAX_DATA); > - kunmap(page); > + memcpy_to_page(page, 0, test->frag_data, MAX_DATA); Why are you temporary mapping a page allocated with the GFP_KERNEL flag? It cannot come from ZONE_HIGHMEM. Fabio > skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA); > } > > return skb; > > -err_free_page: > - __free_page(page); > err_kfree_skb: > kfree_skb(skb); > return NULL; > -- > 2.25.1
