commit 364b2e413c ("sbitmapq: remove struct and member validation
in sbitmapq_init()") allowed the use of the "sbitmapq" command
unconditionally. Without the patch, the command fails with the
following error on kernels without sbitmap:
crash> sbitmapq ffff88015796e550
sbitmapq: invalid structure member offset: sbitmap_queue_sb
FILE: sbitmap.c LINE: 385 FUNCTION: sbitmap_queue_context_load()
Now the command supports Linux 4.9 and later kernels since it was
abstracted out, so it can be limited by the non-existence of the
sbitmap structure.
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
The current struct wait_queue_head was renamed by kernel commit
9d9d676f595b ("sched/wait: Standardize internal naming of wait-queue heads")
at Linux 4.13. Without the patch, on earlier kernels the "sbitmapq"
command fails with the following error:
crash> sbitmapq ffff8801790b3b50
depth = 128
busy = 0
bits_per_word = 32
...
sbitmapq: invalid structure member offset: wait_queue_head_head
FILE: sbitmap.c LINE: 344 FUNCTION: sbitmap_queue_show()
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
The sbitmap_queue.min_shallow_depth member was added by kernel commit
a327553965de ("sbitmap: fix missed wakeups caused by sbitmap_queue_get_shallow()")
at Linux 4.18. Without the patch, on earlier kernels the "sbitmapq"
command fails with the following error:
crash> sbitmapq ffff89bb7638ee50
sbitmapq: invalid structure member offset: sbitmap_queue_min_shallow_depth
FILE: sbitmap.c LINE: 398 FUNCTION: sbitmap_queue_context_load()
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
The sbitmap_word.cleared member was added by kernel commit ea86ea2cdced
("sbitmap: ammortize cost of clearing bits") at Linux 5.0. Without the
patch, on earlier kernels the "sbitmapq" command fails with the
following error:
crash> sbitmapq ffff8f1a3611cf10
sbitmapq: invalid structure member offset: sbitmap_word_cleared
FILE: sbitmap.c LINE: 92 FUNCTION: __sbitmap_weight()
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
The sbitmap_queue.ws_active member was added by kernel commit 5d2ee7122c73
("sbitmap: optimize wakeup check") at Linux 5.0. Without the patch, on
earlier kernels the "sbitmapq" command fails with the following error:
crash> sbitmapq ffff8f1a3611cf10
sbitmapq: invalid structure member offset: sbitmap_queue_ws_active
FILE: sbitmap.c LINE: 393 FUNCTION: sbitmap_queue_context_load()
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Kernel commit 3301bc53358a ("lib/sbitmap: kill 'depth' from sbitmap_word")
removed the depth member from struct sbitmap_word. Without the patch, the
sbitmapq will fail:
crash> sbitmapq 0xffff8e99d0dc8010
sbitmapq: invalid structure member offset: sbitmap_word_depth
FILE: sbitmap.c LINE: 84 FUNCTION: __sbitmap_weight()
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Kernel commit efe1f3a1d583 ("scsi: sbitmap: Maintain allocation
round_robin in sbitmap") moved the round_robin member from struct
sbitmap_queue to struct sbitmap. Without the patch, the sbitmapq
will fail:
crash> sbitmapq 0xffff8e99d0dc8010
sbitmapq: invalid structure member offset: sbitmap_queue_round_robin
FILE: sbitmap.c LINE: 378 FUNCTION: sbitmap_queue_context_load()
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Kernel commit c548e62bcf6a ("scsi: sbitmap: Move allocation hint
into sbitmap") moved the alloc_hint member from struct sbitmap_queue
to struct sbitmap. Without the patch, the sbitmapq will fail:
crash> sbitmapq 0xffff8e99d0dc8010
sbitmapq: invalid structure member offset: sbitmap_queue_alloc_hint
FILE: sbitmap.c LINE: 365 FUNCTION: sbitmap_queue_context_load()
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Let's remove the struct and member validation from sbitmapq_init(), which
will help the crash to display the actual error when the sbitmapq fails.
Without the patch:
crash> sbitmapq ffff8e99d0dc8010
sbitmapq: command not supported or applicable on this architecture or kernel
With the patch:
crash> sbitmapq ffff8e99d0dc8010
sbitmapq: invalid structure member offset: sbitmap_queue_alloc_hint
FILE: sbitmap.c LINE: 365 FUNCTION: sbitmap_queue_context_load()
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
1.) The vmcore file maybe very big.
For example, I have a vmcore file which is over 23G,
and the panic kernel had 767.6G memory,
its max_sect_len is 4468736.
Current code costs too much time to do the following loop:
..............................................
for (i = 1; i < max_sect_len + 1; i++) {
dd->valid_pages[i] = dd->valid_pages[i - 1];
for (j = 0; j < BITMAP_SECT_LEN; j++, pfn++)
if (page_is_dumpable(pfn))
dd->valid_pages[i]++;
..............................................
For my case, it costs about 56 seconds to finish the
big loop.
This patch moves the hweightXX macros to defs.h,
and uses hweight64 to optimize the loop.
For my vmcore, the loop only costs about one second now.
2.) Tests result:
# cat ./commands.txt
quit
Before:
#echo 3 > /proc/sys/vm/drop_caches;
#time ./crash -i ./commands.txt /root/t/vmlinux /root/t/vmcore > /dev/null 2>&1
............................
real 1m54.259s
user 1m12.494s
sys 0m3.857s
............................
After this patch:
#echo 3 > /proc/sys/vm/drop_caches;
#time ./crash -i ./commands.txt /root/t/vmlinux /root/t/vmcore > /dev/null 2>&1
............................
real 0m55.217s
user 0m15.114s
sys 0m3.560s
............................
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
The -p option says, an associated with sbitmap_queue array contains
the pointers on a structure. This allows the sbitmapq command works
correctly with the array of pointers attached to the sbitmap_queue.
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
Patch adds new 'sbitmapq' command. This command dumps
the contents of the sbitmap_queue structure and the used
bits in the bitmap. Also, it shows the dump of a structure
array associated with the sbitmap_queue.
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
