From 28abd2001445d4e702b1dc9147d0015b189cd37a Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 24 Feb 2017 18:28:37 +0000 Subject: [PATCH] postcopy: Load huge pages in one go The existing postcopy RAM load loop already ensures that it glues together whole host-pages from the target page size chunks sent over the wire. Modify the definition of host page that it uses to be the RAM block page size and thus be huge pages where appropriate. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Laurent Vivier Message-Id: <20170224182844.32452-10-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index ff866643b6..9f28da2eab 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2390,7 +2390,7 @@ static int ram_load_postcopy(QEMUFile *f) { int flags = 0, ret = 0; bool place_needed = false; - bool matching_page_sizes = qemu_host_page_size == TARGET_PAGE_SIZE; + bool matching_page_sizes = false; MigrationIncomingState *mis = migration_incoming_get_current(); /* Temporary page that is later 'placed' */ void *postcopy_host_page = postcopy_get_tmp_page(mis); @@ -2420,8 +2420,11 @@ static int ram_load_postcopy(QEMUFile *f) ret = -EINVAL; break; } + matching_page_sizes = block->page_size == TARGET_PAGE_SIZE; /* - * Postcopy requires that we place whole host pages atomically. + * Postcopy requires that we place whole host pages atomically; + * these may be huge pages for RAMBlocks that are backed by + * hugetlbfs. * To make it atomic, the data is read into a temporary page * that's moved into place later. * The migration protocol uses, possibly smaller, target-pages @@ -2429,9 +2432,9 @@ static int ram_load_postcopy(QEMUFile *f) * of a host page in order. */ page_buffer = postcopy_host_page + - ((uintptr_t)host & ~qemu_host_page_mask); + ((uintptr_t)host & (block->page_size - 1)); /* If all TP are zero then we can optimise the place */ - if (!((uintptr_t)host & ~qemu_host_page_mask)) { + if (!((uintptr_t)host & (block->page_size - 1))) { all_zero = true; } else { /* not the 1st TP within the HP */ @@ -2449,7 +2452,7 @@ static int ram_load_postcopy(QEMUFile *f) * page */ place_needed = (((uintptr_t)host + TARGET_PAGE_SIZE) & - ~qemu_host_page_mask) == 0; + (block->page_size - 1)) == 0; place_source = postcopy_host_page; } last_host = host; -- 2.11.0