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5aff71767c
All references to pages are being removed from the multifd worker threads in order to allow multifd to deal with different payload types. multifd_send_zero_page_detect() is called by all multifd migration paths that deal with pages and is the last spot where zero pages and normal page amounts are adjusted. Move the pages accounting into that function. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de>
95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/*
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* Multifd zero page detection implementation.
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*
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* Copyright (c) 2024 Bytedance Inc
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*
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* Authors:
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* Hao Xiang <hao.xiang@bytedance.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "qemu/cutils.h"
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#include "exec/ramblock.h"
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#include "migration.h"
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#include "migration-stats.h"
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#include "multifd.h"
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#include "options.h"
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#include "ram.h"
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static bool multifd_zero_page_enabled(void)
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{
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return migrate_zero_page_detection() == ZERO_PAGE_DETECTION_MULTIFD;
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}
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static void swap_page_offset(ram_addr_t *pages_offset, int a, int b)
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{
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ram_addr_t temp;
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if (a == b) {
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return;
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}
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temp = pages_offset[a];
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pages_offset[a] = pages_offset[b];
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pages_offset[b] = temp;
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}
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/**
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* multifd_send_zero_page_detect: Perform zero page detection on all pages.
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*
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* Sorts normal pages before zero pages in p->pages->offset and updates
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* p->pages->normal_num.
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*
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* @param p A pointer to the send params.
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*/
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void multifd_send_zero_page_detect(MultiFDSendParams *p)
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{
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MultiFDPages_t *pages = &p->data->u.ram;
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RAMBlock *rb = pages->block;
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int i = 0;
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int j = pages->num - 1;
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if (!multifd_zero_page_enabled()) {
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pages->normal_num = pages->num;
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goto out;
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}
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/*
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* Sort the page offset array by moving all normal pages to
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* the left and all zero pages to the right of the array.
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*/
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while (i <= j) {
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uint64_t offset = pages->offset[i];
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if (!buffer_is_zero(rb->host + offset, multifd_ram_page_size())) {
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i++;
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continue;
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}
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swap_page_offset(pages->offset, i, j);
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ram_release_page(rb->idstr, offset);
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j--;
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}
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pages->normal_num = i;
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out:
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stat64_add(&mig_stats.normal_pages, pages->normal_num);
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stat64_add(&mig_stats.zero_pages, pages->num - pages->normal_num);
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}
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void multifd_recv_zero_page_process(MultiFDRecvParams *p)
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{
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for (int i = 0; i < p->zero_num; i++) {
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void *page = p->host + p->zero[i];
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if (ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i])) {
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memset(page, 0, multifd_ram_page_size());
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} else {
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ramblock_recv_bitmap_set_offset(p->block, p->zero[i]);
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}
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}
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}
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