The maximal size which may be used in the kernel for sending TCP data
on restore is varies depending on how many memory installed on the
system, moreover the memory allocated for "read queue" is bigger than
used for "write queue". Thus when we checkpointed a big slab of data
we need to figure out which size is allowed for sending data on restore.
For this we read /proc/sys/net/ipv4/tcp_[wmem|rmem] on restore and calculate
the size needed, then we simply chop data to segements and send it
in a loop.
Typical output on restore is something like
| (00.013001) 30110: TCP queue memory limits are 2097152:3145728
https://bugzilla.openvz.org/show_bug.cgi?id=2751
[xemul: moved stuff to kerndat.c]
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I've just occasionally tried to run criu on old openvz
kernel and the error message was looking somehow strange
to me
| Error (kerndat.c:39): Can't stat piggie: No such file or directory
Lets produce some more detailed error text.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This file was created for backward compatibility with
not-yet-patched kernel. Now we can remove it.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This constants are system wide, so move them to mem.h
header for reuse sake.
[ xemul: It was kerndat.h in the patch ]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The soft-dirty API has changed slightly -- now the bit in
question _is_ in pagemap file (not pagemap2) but to see it
we have to reset soft-dirty for anyone first.
Teach the kerndat soft-dirty checker this fact. The actual
pagemap reading code already knows select pagemap/pagemap2
file itself.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Update to commit 78b8abe9a53884686d4f70d1376f85108cbfc857
I find a compile err:
kerndat.c: In function 'kerndat_get_dirty_track':
kerndat.c:78:6: error: ignoring return value of 'read', declared with attribute warn_unused_result [-Werror=unused-result]
cc1: all warnings being treated as errors
make[2]: *** [kerndat.o] Error 1
make[1]: *** [built-in.o] Error 2
make[1]: Leaving directory `/home/clb/crtools'
make: *** [all] Error 2
Signed-off-by: Libo Chen <libo.chen@huawei.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
One of such things we use right now is the device for anon shmem
mappings backing. In the furure this can be extended to check for
various kernel features.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
