On 4/28/26 12:00, Vineet Agarwal wrote: > file_setup_area() currently allocates anonymous memory, fills it, > and writes it into the backing file used for collapse testing. > > Instead of copying data through write(), resize the file with > ftruncate(), map it directly with MAP_SHARED, and initialize the > mapped area in place. > > This simplifies the setup path and avoids the need for explicit > partial write handling.
Please a) Wait a bit longer before you resend. b) Don't send as reply to earlier revisions. > > Signed-off-by: Vineet Agarwal <[email protected]> > --- > tools/testing/selftests/mm/khugepaged.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/selftests/mm/khugepaged.c > b/tools/testing/selftests/mm/khugepaged.c > index 3fe7ef04ac62..57ca4224bd5a 100644 > --- a/tools/testing/selftests/mm/khugepaged.c > +++ b/tools/testing/selftests/mm/khugepaged.c > @@ -369,7 +369,6 @@ static void *file_setup_area(int nr_hpages) > int fd; > void *p; > unsigned long size; > - Unrelated change. > unlink(finfo.path); /* Cleanup from previous failed tests */ > printf("Creating %s for collapse%s...", finfo.path, > finfo.type == VMA_SHMEM ? " (tmpfs)" : ""); > @@ -381,11 +380,21 @@ static void *file_setup_area(int nr_hpages) > } > > size = nr_hpages * hpage_pmd_size; > - p = alloc_mapping(nr_hpages); > + if (ftruncate(fd, size)) { > + perror("ftruncate()"); > + close(fd); > + exit(EXIT_FAILURE); > + } > + p = mmap(BASE_ADDR, size, PROT_READ | PROT_WRITE, > + MAP_SHARED, fd, 0); > + if (p == MAP_FAILED || p != BASE_ADDR) { > + perror("mmap()"); > + close(fd); > + exit(EXIT_FAILURE); > + } > fill_memory(p, 0, size); > - write(fd, p, size); > - close(fd); > munmap(p, size); > + close(fd); That change is not strictly required. We can munmap() after close(). Apart from that LGTM. -- Cheers, David
