On Wed, May 10, 2023 at 8:21 PM Michael Ellerman <m...@ellerman.id.au> wrote: > > Nhat Pham <npha...@gmail.com> writes: > > Test cachestat on a newly created file, /dev/ files, and /proc/ files. > > Also test on a shmem file (which can also be tested with huge pages > > since tmpfs supports huge pages). > > > > Signed-off-by: Nhat Pham <npha...@gmail.com> > ... > > diff --git a/tools/testing/selftests/cachestat/test_cachestat.c > > b/tools/testing/selftests/cachestat/test_cachestat.c > > new file mode 100644 > > index 000000000000..c3823b809c25 > > --- /dev/null > > +++ b/tools/testing/selftests/cachestat/test_cachestat.c > > @@ -0,0 +1,258 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +#define _GNU_SOURCE > > + > > +#include <stdio.h> > > +#include <stdbool.h> > > +#include <linux/kernel.h> > > +#include <linux/mman.h> > > +#include <sys/mman.h> > > +#include <sys/shm.h> > > +#include <sys/syscall.h> > > +#include <unistd.h> > > +#include <string.h> > > +#include <fcntl.h> > > +#include <errno.h> > > + > > +#include "../kselftest.h" > > + > > +static const char * const dev_files[] = { > > + "/dev/zero", "/dev/null", "/dev/urandom", > > + "/proc/version", "/proc" > > +}; > > +static const int cachestat_nr = 451; > > + > > +void print_cachestat(struct cachestat *cs) > > +{ > > + ksft_print_msg( > > + "Using cachestat: Cached: %lu, Dirty: %lu, Writeback: %lu, Evicted: > > %lu, Recently Evicted: %lu\n", > > + cs->nr_cache, cs->nr_dirty, cs->nr_writeback, > > + cs->nr_evicted, cs->nr_recently_evicted); > > +} > > + > > +bool write_exactly(int fd, size_t filesize) > > +{ > > + char data[filesize]; > > On kernels with 64K pages (powerpc at least), this tries to allocate > 64MB on the stack which segfaults. > > Allocating data with malloc avoids the problem and allows the test to > pass. > > Looks like this commit is still in mm-unstable, so maybe Andrew can > squash the incremental diff below in, if it looks OK to you. The diff is > a bit big because I unindented the body of the function. > > cheers > > > diff --git a/tools/testing/selftests/cachestat/test_cachestat.c > b/tools/testing/selftests/cachestat/test_cachestat.c > index 9be2262e5c17..54d09b820ed4 100644 > --- a/tools/testing/selftests/cachestat/test_cachestat.c > +++ b/tools/testing/selftests/cachestat/test_cachestat.c > @@ -31,48 +31,59 @@ void print_cachestat(struct cachestat *cs) > > bool write_exactly(int fd, size_t filesize) > { > - char data[filesize]; > - bool ret = true; > int random_fd = open("/dev/urandom", O_RDONLY); > + char *cursor, *data; > + int remained; > + bool ret; > > if (random_fd < 0) { > ksft_print_msg("Unable to access urandom.\n"); > ret = false; > goto out; > - } else { > - int remained = filesize; > - char *cursor = data; > + } > > - while (remained) { > - ssize_t read_len = read(random_fd, cursor, remained); > + data = malloc(filesize); > + if (!data) { > + ksft_print_msg("Unable to allocate data.\n"); > + ret = false; > + goto close_random_fd; > + } > > - if (read_len <= 0) { > - ksft_print_msg("Unable to read from > urandom.\n"); > - ret = false; > - goto close_random_fd; > - } > + remained = filesize; > + cursor = data; > > - remained -= read_len; > - cursor += read_len; > + while (remained) { > + ssize_t read_len = read(random_fd, cursor, remained); > + > + if (read_len <= 0) { > + ksft_print_msg("Unable to read from urandom.\n"); > + ret = false; > + goto out_free_data; > } > > - /* write random data to fd */ > - remained = filesize; > - cursor = data; > - while (remained) { > - ssize_t write_len = write(fd, cursor, remained); > + remained -= read_len; > + cursor += read_len; > + } > > - if (write_len <= 0) { > - ksft_print_msg("Unable write random data to > file.\n"); > - ret = false; > - goto close_random_fd; > - } > + /* write random data to fd */ > + remained = filesize; > + cursor = data; > + while (remained) { > + ssize_t write_len = write(fd, cursor, remained); > > - remained -= write_len; > - cursor += write_len; > + if (write_len <= 0) { > + ksft_print_msg("Unable write random data to file.\n"); > + ret = false; > + goto out_free_data; > } > + > + remained -= write_len; > + cursor += write_len; > } > > + ret = true; > +out_free_data: > + free(data); > close_random_fd: > close(random_fd); > out: >
Oh this is nice! I had to make a similar fix in another test of mine, but forgot about it in this context. LGTM. For verification, I have applied the diff and test on my own local setup. Things still pass. Acked-by: Nhat Pham <npha...@gmail.com>