#1 adds support for MADV_POPULATE_WRITE, #2 cleans up the code to avoid global variables and prepare for concurrency, #3 and #4 optimize thread handling, #5 makes os_mem_prealloc() safe to be called from multiple threads concurrently and #6 makes the SIGBUS handler coexist cleanly with the MCE SIGBUS handler under Linux.
Details regarding MADV_POPULATE_WRITE can be found in introducing upstream Linux commit 4ca9b3859dac ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables") and in the latest man page patch [1]. v1 -> v2: - "util/oslib-posix: Support MADV_POPULATE_WRITE for os_mem_prealloc()" -- Handle thread with no data to initialize -- Always set use_madv_populate_write properly -- Add comment regarding future fallocate() optimization - "util/oslib-posix: Don't create too many threads with small memory or little pages" -- Added - "util/oslib-posix: Avoid creating a single thread with MADV_POPULATE_WRITE" -- Added - "util/oslib-posix: Support concurrent os_mem_prealloc() invocation" -- Add missing g_once_init_leave() -- Move g_once_init_enter() to the place where it is actually needed - "util/oslib-posix: Forward SIGBUS to MCE handler under Linux" -- Added [1] https://lkml.kernel.org/r/20210712083917.16361-1-da...@redhat.com Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: "Michael S. Tsirkin" <m...@redhat.com> Cc: Igor Mammedov <imamm...@redhat.com> Cc: Eduardo Habkost <ehabk...@redhat.com> Cc: Dr. David Alan Gilbert <dgilb...@redhat.com> Cc: Marek Kedzierski <mkedz...@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.li...@gmail.com> Cc: Daniel P. Berrangé <berra...@redhat.com> David Hildenbrand (6): util/oslib-posix: Support MADV_POPULATE_WRITE for os_mem_prealloc() util/oslib-posix: Introduce and use MemsetContext for touch_all_pages() util/oslib-posix: Don't create too many threads with small memory or little pages util/oslib-posix: Avoid creating a single thread with MADV_POPULATE_WRITE util/oslib-posix: Support concurrent os_mem_prealloc() invocation util/oslib-posix: Forward SIGBUS to MCE handler under Linux include/qemu/osdep.h | 7 ++ softmmu/cpus.c | 4 + util/oslib-posix.c | 220 +++++++++++++++++++++++++++++++++---------- 3 files changed, 181 insertions(+), 50 deletions(-) -- 2.31.1