Hi Right now, multifd does a write() for the header and a writev() for each group of pages. Simplify it so we send the header as another member of the IOV.
Once there, I got several simplifications: * is_zero_range() was used only once, just use its body. * same with is_zero_page(). * Be consintent and use offset insed the ramblock everywhere. * Now that we have the offsets of the ramblock, we can drop the iov. * Now that nothing uses iov's except NOCOMP method, move the iovs from pages to methods. * Now we can use iov's with a single field for zlib/zstd. * send_write() method is the same in all the implementaitons, so use it directly. * Now, we can use a single writev() to write everything. ToDo: Move zero page detection to the multifd thrteads. With RAM in the Terabytes size, the detection of the zero page takes too much time on the main thread. Last patch on the series removes the detection of zero pages in the main thread for multifd. In the next series post, I will add how to detect the zero pages and send them on multifd channels. Please review. Later, Juan. Juan Quintela (11): migration: Remove is_zero_range() dump: Remove is_zero_page() multifd: Fill offset and block for reception multifd: Make zstd compression method not use iovs multifd: Make zlib compression method not use iovs migration: Move iov from pages to params multifd: Make zlib use iov's multifd: Make zstd use iov's multifd: Remove send_write() method multifd: Use a single writev on the send side migration: Use multifd before we check for the zero page migration/multifd.h | 10 ++++--- dump/dump.c | 10 +------ migration/multifd-zlib.c | 40 ++++++++------------------ migration/multifd-zstd.c | 41 ++++++++------------------ migration/multifd.c | 62 ++++++++++++++++++---------------------- migration/ram.c | 31 +++++++++----------- 6 files changed, 72 insertions(+), 122 deletions(-) -- 2.33.1
