Commit 44c3b58c authored by Michael R. Hines's avatar Michael R. Hines Committed by Juan Quintela
Browse files

rdma: introduce ram_handle_compressed() 



This gives RDMA shared access to madvise() on the destination side
when an entire chunk is found to be zero.

Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarChegu Vinod <chegu_vinod@hp.com>
Tested-by: default avatarChegu Vinod <chegu_vinod@hp.com>
Tested-by: default avatarMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: default avatarMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent de7b685c

arch_init.c

+19 −10
Original line number Diff line number Diff line
@@ -808,6 +808,24 @@ static inline void *host_from_stream_offset(QEMUFile *f, 
    return NULL;

}



/*

 * If a page (or a whole RDMA chunk) has been

 * determined to be zero, then zap it.

 */

void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)

{

    if (ch != 0 || !is_zero_page(host)) {

        memset(host, ch, size);

#ifndef _WIN32

        if (ch == 0 &&

            (!kvm_enabled() || kvm_has_sync_mmu()) &&

            getpagesize() <= TARGET_PAGE_SIZE) {

            qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);

        }

#endif

    }

}



static int ram_load(QEMUFile *f, void *opaque, int version_id)

{

    ram_addr_t addr;
@@ -879,16 +897,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) 
            }



            ch = qemu_get_byte(f);

            if (ch != 0 || !is_zero_page(host)) {

                memset(host, ch, TARGET_PAGE_SIZE);

#ifndef _WIN32

                if (ch == 0 &&

                    (!kvm_enabled() || kvm_has_sync_mmu()) &&

                    getpagesize() <= TARGET_PAGE_SIZE) {

                    qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);

                }

#endif

            }

            ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);

        } else if (flags & RAM_SAVE_FLAG_PAGE) {

            void *host;

include/migration/migration.h

+2 −0
Original line number Diff line number Diff line
@@ -109,6 +109,8 @@ uint64_t xbzrle_mig_pages_transferred(void); 
uint64_t xbzrle_mig_pages_overflow(void);

uint64_t xbzrle_mig_pages_cache_miss(void);



void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);



/**

 * @migrate_add_blocker - prevent migration from proceeding

 *