Hi all,
During "make kselftest" there is an error in selftest/vm/cow.c compilation on platform:
- Lenovo desktop 10TX000VCR (LENOVO_MT_10TX_BU_Lenovo_FM_V530S-07ICB) - AlmaLinux 8.7 (CentOS fork) - gcc 8.5.0 20210514 (Red Hat 8.5.0-15) - vanilla kernel 6.2-rc2 from the torvalds mainline tree.
Compilation fails to find "#define MADV_PAGEOUT":
[root@pc-mtodorov vm]# make gcc -Wall -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c vm_util.c -lrt -lpthread -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm/cow cow.c: In function ‘do_run_with_base_page’: cow.c:755:26: error: ‘MADV_PAGEOUT’ undeclared (first use in this function); did you mean ‘MADV_RANDOM’? madvise(mem, pagesize, MADV_PAGEOUT); ^~~~~~~~~~~~ MADV_RANDOM cow.c:755:26: note: each undeclared identifier is reported only once for each function it appears in cow.c: In function ‘do_run_with_thp’: cow.c:914:22: error: ‘MADV_PAGEOUT’ undeclared (first use in this function); did you mean ‘MADV_RANDOM’? madvise(mem, size, MADV_PAGEOUT); ^~~~~~~~~~~~ MADV_RANDOM make: *** [../lib.mk:145: /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm/cow] Error 1 [root@pc-mtodorov vm]#
MADV_PAGEOUT is defined in #include <asm-generic/mman-common.h> :
[root@pc-mtodorov vm]# grep MADV_PAGEOUT -r /usr/include /usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ [root@pc-mtodorov vm]# grep MADV_PAGEOUT -r ../../../../usr/include ../../../../usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ [root@pc-mtodorov vm]#
However, gcc -E shows that asm-generic/mman-common.h is somehow never included:
--------------------------------------------------------------------------------------------- [root@pc-mtodorov vm]# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | cat -s | less # 1 "/usr/include/sys/mman.h" 1 3 4 # 25 "/usr/include/sys/mman.h" 3 4 # 1 "/usr/lib/gcc/x86_64-redhat-linux/8/include/stddef.h" 1 3 4 # 26 "/usr/include/sys/mman.h" 2 3 4 # 41 "/usr/include/sys/mman.h" 3 4 # 1 "/usr/include/bits/mman.h" 1 3 4 # 49 "/usr/include/bits/mman.h" 3 4 # 1 "/usr/include/bits/mman-linux.h" 1 3 4 # 117 "/usr/include/bits/mman-linux.h" 3 4 # 1 "/usr/include/bits/mman-shared.h" 1 3 4 # 42 "/usr/include/bits/mman-shared.h" 3 4
int memfd_create (const char *__name, unsigned int __flags) __attribute__ ((__nothrow__ , __leaf__)); int mlock2 (const void *__addr, size_t __length, unsigned int __flags) __attribute__ ((__nothrow__ , __leaf__)); int pkey_alloc (unsigned int __flags, unsigned int __access_rights) __attribute__ ((__nothrow__ , __leaf__)); int pkey_set (int __key, unsigned int __access_rights) __attribute__ ((__nothrow__ , __leaf__)); int pkey_get (int __key) __attribute__ ((__nothrow__ , __leaf__)); int pkey_free (int __key) __attribute__ ((__nothrow__ , __leaf__)); int pkey_mprotect (void *__addr, size_t __len, int __prot, int __pkey) __attribute__ ((__nothrow__ , __leaf__));
# 117 "/usr/include/bits/mman-linux.h" 2 3 4 # 49 "/usr/include/bits/mman.h" 2 3 4 # 42 "/usr/include/sys/mman.h" 2 3 4
# 57 "/usr/include/sys/mman.h" 3 4 extern void *mmap (void *__addr, size_t __len, int __prot, int __flags, int __fd, __off_t __offset) __attribute__ ((__nothrow__ , __leaf__)); # 70 "/usr/include/sys/mman.h" 3 4 extern void *mmap64 (void *__addr, size_t __len, int __prot, int __flags, int __fd, __off64_t __offset) __attribute__ ((__nothrow__ , __leaf__));
extern int munmap (void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int mprotect (void *__addr, size_t __len, int __prot) __attribute__ ((__nothrow__ , __leaf__)); extern int msync (void *__addr, size_t __len, int __flags); extern int madvise (void *__addr, size_t __len, int __advice) __attribute__ ((__nothrow__ , __leaf__)); extern int posix_madvise (void *__addr, size_t __len, int __advice) __attribute__ ((__nothrow__ , __leaf__)); extern int mlock (const void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int munlock (const void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int mlockall (int __flags) __attribute__ ((__nothrow__ , __leaf__)); extern int munlockall (void) __attribute__ ((__nothrow__ , __leaf__)); extern int mincore (void *__start, size_t __len, unsigned char *__vec) __attribute__ ((__nothrow__ , __leaf__));
# 133 "/usr/include/sys/mman.h" 3 4
extern void *mremap (void *__addr, size_t __old_len, size_t __new_len, int __flags, ...) __attribute__ ((__nothrow__ , __leaf__)); extern int remap_file_pages (void *__start, size_t __size, int __prot, size_t __pgoff, int __flags) __attribute__ ((__nothrow__ , __leaf__)); extern int shm_open (const char *__name, int __oflag, mode_t __mode); extern int shm_unlink (const char *__name); -------------------------------------------------------------------------------------------------------
FYI:
On the platform:
- Ubuntu 22.10 kinetic kudu - gcc 12.2.0 - same 6.2-rc2
, MADV_PAGEOUT is also defined in bits/mmap-linux.h, so the compile passes.
root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# grep MADV_PAGEOUT -r /usr/include /usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ /usr/include/x86_64-linux-gnu/bits/mman-linux.h:# define MADV_PAGEOUT 21 /* Reclaim these pages. */ root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# grep MADV_PAGEOUT -r ../../../../usr/include ../../../../usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm#
However, mman-common.h from ../../../../usr/include/asm-generic/mman-common.h is also not included, as of "gcc -E", but only bits/mman-linux.h:
root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | grep mman-common.h root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | grep mman-linux.h # 1 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 1 3 4 # 119 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 3 4 # 120 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 2 3 4 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm#
I hope this is enough information for you to debug the issue.
I am standing by for any additional diagnostics needed.
Regards, Mirsad
On 08.01.23 11:58, Mirsad Goran Todorovac wrote:
Hi all,
During "make kselftest" there is an error in selftest/vm/cow.c compilation on platform:
- Lenovo desktop 10TX000VCR (LENOVO_MT_10TX_BU_Lenovo_FM_V530S-07ICB)
- AlmaLinux 8.7 (CentOS fork)
- gcc 8.5.0 20210514 (Red Hat 8.5.0-15)
- vanilla kernel 6.2-rc2 from the torvalds mainline tree.
Compilation fails to find "#define MADV_PAGEOUT":
[root@pc-mtodorov vm]# make gcc -Wall -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c vm_util.c -lrt -lpthread -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm/cow cow.c: In function ‘do_run_with_base_page’: cow.c:755:26: error: ‘MADV_PAGEOUT’ undeclared (first use in this function); did you mean ‘MADV_RANDOM’? madvise(mem, pagesize, MADV_PAGEOUT); ^~~~~~~~~~~~ MADV_RANDOM cow.c:755:26: note: each undeclared identifier is reported only once for each function it appears in cow.c: In function ‘do_run_with_thp’: cow.c:914:22: error: ‘MADV_PAGEOUT’ undeclared (first use in this function); did you mean ‘MADV_RANDOM’? madvise(mem, size, MADV_PAGEOUT); ^~~~~~~~~~~~ MADV_RANDOM make: *** [../lib.mk:145: /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm/cow] Error 1 [root@pc-mtodorov vm]#
MADV_PAGEOUT is defined in #include <asm-generic/mman-common.h> :
[root@pc-mtodorov vm]# grep MADV_PAGEOUT -r /usr/include /usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ [root@pc-mtodorov vm]# grep MADV_PAGEOUT -r ../../../../usr/include ../../../../usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ [root@pc-mtodorov vm]#
However, gcc -E shows that asm-generic/mman-common.h is somehow never included:
[root@pc-mtodorov vm]# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | cat -s | less # 1 "/usr/include/sys/mman.h" 1 3 4 # 25 "/usr/include/sys/mman.h" 3 4 # 1 "/usr/lib/gcc/x86_64-redhat-linux/8/include/stddef.h" 1 3 4 # 26 "/usr/include/sys/mman.h" 2 3 4 # 41 "/usr/include/sys/mman.h" 3 4 # 1 "/usr/include/bits/mman.h" 1 3 4 # 49 "/usr/include/bits/mman.h" 3 4 # 1 "/usr/include/bits/mman-linux.h" 1 3 4 # 117 "/usr/include/bits/mman-linux.h" 3 4 # 1 "/usr/include/bits/mman-shared.h" 1 3 4 # 42 "/usr/include/bits/mman-shared.h" 3 4
int memfd_create (const char *__name, unsigned int __flags) __attribute__ ((__nothrow__ , __leaf__)); int mlock2 (const void *__addr, size_t __length, unsigned int __flags) __attribute__ ((__nothrow__ , __leaf__)); int pkey_alloc (unsigned int __flags, unsigned int __access_rights) __attribute__ ((__nothrow__ , __leaf__)); int pkey_set (int __key, unsigned int __access_rights) __attribute__ ((__nothrow__ , __leaf__)); int pkey_get (int __key) __attribute__ ((__nothrow__ , __leaf__)); int pkey_free (int __key) __attribute__ ((__nothrow__ , __leaf__)); int pkey_mprotect (void *__addr, size_t __len, int __prot, int __pkey) __attribute__ ((__nothrow__ , __leaf__));
# 117 "/usr/include/bits/mman-linux.h" 2 3 4 # 49 "/usr/include/bits/mman.h" 2 3 4 # 42 "/usr/include/sys/mman.h" 2 3 4
# 57 "/usr/include/sys/mman.h" 3 4 extern void *mmap (void *__addr, size_t __len, int __prot, int __flags, int __fd, __off_t __offset) __attribute__ ((__nothrow__ , __leaf__)); # 70 "/usr/include/sys/mman.h" 3 4 extern void *mmap64 (void *__addr, size_t __len, int __prot, int __flags, int __fd, __off64_t __offset) __attribute__ ((__nothrow__ , __leaf__));
extern int munmap (void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int mprotect (void *__addr, size_t __len, int __prot) __attribute__ ((__nothrow__ , __leaf__)); extern int msync (void *__addr, size_t __len, int __flags); extern int madvise (void *__addr, size_t __len, int __advice) __attribute__ ((__nothrow__ , __leaf__)); extern int posix_madvise (void *__addr, size_t __len, int __advice) __attribute__ ((__nothrow__ , __leaf__)); extern int mlock (const void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int munlock (const void *__addr, size_t __len) __attribute__ ((__nothrow__ , __leaf__)); extern int mlockall (int __flags) __attribute__ ((__nothrow__ , __leaf__)); extern int munlockall (void) __attribute__ ((__nothrow__ , __leaf__)); extern int mincore (void *__start, size_t __len, unsigned char *__vec) __attribute__ ((__nothrow__ , __leaf__));
# 133 "/usr/include/sys/mman.h" 3 4
extern void *mremap (void *__addr, size_t __old_len, size_t __new_len, int __flags, ...) __attribute__ ((__nothrow__ , __leaf__)); extern int remap_file_pages (void *__start, size_t __size, int __prot, size_t __pgoff, int __flags) __attribute__ ((__nothrow__ , __leaf__)); extern int shm_open (const char *__name, int __oflag, mode_t __mode); extern int shm_unlink (const char *__name);
FYI:
On the platform:
- Ubuntu 22.10 kinetic kudu
- gcc 12.2.0
- same 6.2-rc2
, MADV_PAGEOUT is also defined in bits/mmap-linux.h, so the compile passes.
root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# grep MADV_PAGEOUT -r /usr/include /usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ /usr/include/x86_64-linux-gnu/bits/mman-linux.h:# define MADV_PAGEOUT 21 /* Reclaim these pages. */ root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# grep MADV_PAGEOUT -r ../../../../usr/include ../../../../usr/include/asm-generic/mman-common.h:#define MADV_PAGEOUT 21 /* reclaim these pages */ root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm#
However, mman-common.h from ../../../../usr/include/asm-generic/mman-common.h is also not included, as of "gcc -E", but only bits/mman-linux.h:
root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | grep mman-common.h root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm# gcc -Wall -E -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../.. -I /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -isystem /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/../../../usr/include -no-pie cow.c | grep mman-linux.h # 1 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 1 3 4 # 119 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 3 4 # 120 "/usr/include/x86_64-linux-gnu/bits/mman-linux.h" 2 3 4 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/vm#
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.
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>
-- Mirsad Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu
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).
But yeah, I saw that userfaultfd.c was fixed that way:
commit b773827e361952b3f53ac6fa4c4e39ccd632102e Author: Chengming Zhou zhouchengming@bytedance.com 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@redhat.com
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@bytedance.com 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@redhat.com
You're the boss :)
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?
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@bytedance.com 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@redhat.com
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?
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