On 10.01.23 13:25, Mirsad Todorovac wrote:
On 1/10/23 11:05, David Hildenbrand wrote:
On 09.01.23 22:41, Mirsad Goran Todorovac wrote:
On 1/9/2023 5:42 PM, David Hildenbrand wrote:
Hi, thank you for your reply.
I hope this is enough information for you to debug the issue.
I am standing by for any additional diagnostics needed.
Won't userfaultfd.c fail in a similar way?
Anyhow, khugepaged.c jas
#ifndef MADV_PAGEOUT
#define MADV_PAGEOUT 21
#endif
So most probably we should do the same.
Actually, David, it turned out that userfaultfd.c compiled
out-of-the-box, and side-by-side comparison showed that it also included
"/home/marvin/linux/kernel/linux_torvalds/usr/include/asm-generic/mman-common.h"
The only remaining difference was including <linux/mman.h>, which fixed
the issue w/o #ifdef ... #endif
Hope this helps.
Please find the following diff.
Regards,
Mirsad
------------------------------------------------------------------------------
diff --git a/tools/testing/selftests/vm/cow.c
b/tools/testing/selftests/vm/cow.c
index 26f6ea3079e2..dd8cf12c6776 100644
--- a/tools/testing/selftests/vm/cow.c
+++ b/tools/testing/selftests/vm/cow.c
@@ -16,6 +16,7 @@
#include <fcntl.h>
#include <dirent.h>
#include <assert.h>
+#include <linux/mman.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
I already sent a different fix [1]. I suspect when including
linux/mman.h, it would still be problematic with older kernel
headers that lack MADV_PAGEOUT (< v5.4).
I see your point.
But yeah, I saw that userfaultfd.c was fixed that way:
commit b773827e361952b3f53ac6fa4c4e39ccd632102e
Author: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Date: Fri Mar 4 20:29:04 2022 -0800
kselftest/vm: fix tests build with old libc
The error message when I build vm tests on debian10 (GLIBC 2.28):
userfaultfd.c: In function `userfaultfd_pagemap_test':
userfaultfd.c:1393:37: error: `MADV_PAGEOUT' undeclared (first use
in this function); did you mean `MADV_RANDOM'?
if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
^~~~~~~~~~~~
MADV_RANDOM
This patch includes these newer definitions from UAPI linux/mman.h, is
useful to fix tests build on systems without these definitions in
glibc
sys/mman.h.
[1] https://lkml.kernel.org/r/20230109171255.488749-1-david@xxxxxxxxxx
You're the boss :)
Heh, no I'm not :) I'm just raising that this turned out to be
problematic unfortunately.
However, IMHO, having MADV_PAGEOUT defined in three or four places could
make like miserable. OK, it is unlikely to change value, but something
tells me that the right way to do it is to guarantee that the macro
definition is unique.
I don't know what would be the right thing to do in pre-5.4 kernels
w/o MADV_PAGEOUT defined.
Probably then the "(madvise(area_dst, test_pgsize, MADV_PAGEOUT)" gives
EINVAL or is undefined?
Yes. The expectation is that it fails with ENOSYS or EINVAL if the
kernel doesn't support it. The kernel might be different to the
installed kernel headers.
In an ideal world, we'd be using the in-tree headers -- they are
guaranteed to define what we need. So far, I failed to make it work (I
thought it would work as expected before I had to do above mentioned
fix). Maybe that can be made working?
--
Thanks,
David / dhildenb
