Implemented recvbitmap tracking of received pages in multifd.
If the zero page appears for the first time in the recvbitmap, this
page is not checked and set.
If the zero page has already appeared in the recvbitmap, there is no
need to check the data but directly set the data to 0, because it is
unlikely that the zero page will be migrated multiple times.
Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240401154110.2028453-2-yuan1.liu@intel.com
[peterx: touch up the comment, as the bitmap is used outside postcopy now]
Signed-off-by: Peter Xu <peterx@redhat.com>
1. Add zero_pages field in MultiFDPacket_t.
2. Implements the zero page detection and handling on the multifd
threads for non-compression, zlib and zstd compression backends.
3. Added a new value 'multifd' in ZeroPageDetection enumeration.
4. Adds zero page counters and updates multifd send/receive tracing
format to track the newly added counters.
Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240311180015.3359271-5-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
Next patches will abstract the type of data being received by the
channels, so do some cleanup now to remove references to pages and
dependency on 'normal_num'.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-14-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
Use a more specific name for the compression data so we can use the
generic for the multifd core code.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-13-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
This patch redefines the interfacing of ->send_prepare(). It further
simplifies multifd_send_thread() especially on zero copy.
Now with the new interface, we require the hook to do all the work for
preparing the IOVs to send. After it's completed, the IOVs should be ready
to be dumped into the specific multifd QIOChannel later.
So now the API looks like:
p->pages -----------> send_prepare() -------------> IOVs
This also prepares for the case where the input can be extended to even not
any p->pages. But that's for later.
This patch will achieve similar goal of what Fabiano used to propose here:
https://lore.kernel.org/r/20240126221943.26628-1-farosas@suse.de
However the send() interface may not be necessary. I'm boldly attaching a
"Co-developed-by" for Fabiano.
Co-developed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240202102857.110210-14-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
This array is redundant when p->pages exists. Now we extended the life of
p->pages to the whole period where pending_job is set, it should be safe to
always use p->pages->offset[] rather than p->normal[]. Drop the array.
Alongside, the normal_num is also redundant, which is the same to
p->pages->num.
This doesn't apply to recv side, because there's no extra buffering on recv
side, so p->normal[] array is still needed.
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240202102857.110210-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
We were calling qemu_target_page_size() left and right.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Rename num_normal_pages to total_normal_pages (peter)
We are only sending normal pages through multifd channels.
Later on this series, we are going to also send zero pages.
We are going to detect if a page is zero or non zero in the multifd
channel thread, not on the main thread.
So we receive an array of pages page->offset[N]
And we will end with:
p->normal[N - zero_pages]
p->zero[zero_pages].
In this patch, we just copy all the pages in offset to normal.
for (i = 0; i < pages->num; i++) {
p->narmal[p->normal_num] = pages->offset[i];
p->normal_num++:
}
Later in the series this becomes:
for (i = 0; i < pages->num; i++) {
if (buffer_is_zero(page->offset[i])) {
p->zerol[p->zero_num] = pages->offset[i];
p->zero_num++:
} else {
p->narmal[p->normal_num] = pages->offset[i];
p->normal_num++:
}
}
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Improving comment (dave)
Renaming num_normal_pages to total_normal_pages (peter)
It happens that there are functions to calculate the worst possible
compression size for a packet. Use them.
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
So printing it as %d is wrong. Notice that for the channel id, that
is an uint8_t, but I changed it anyways for consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
We are dividing by page_size to multiply again in the only use.
Once there, improve the comments.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
