On Mon, Jul 10, 2023 at 2:07 PM Markus Armbruster <[email protected]> wrote: > > Jason Wang <[email protected]> writes: > > > On Sun, Jul 9, 2023 at 11:48 PM Bin Meng <[email protected]> wrote: > >> > >> On Wed, Jun 28, 2023 at 11:29 PM Bin Meng <[email protected]> wrote: > >> > > >> > > >> > Current codes using a brute-force traversal of all file descriptors > >> > do not scale on a system where the maximum number of file descriptors > >> > is set to a very large value (e.g.: in a Docker container of Manjaro > >> > distribution it is set to 1073741816). QEMU just looks frozen during > >> > start-up. > >> > > >> > The close-on-exec flag (O_CLOEXEC) was introduced since Linux kernel > >> > 2.6.23, FreeBSD 8.3, OpenBSD 5.0, Solaris 11. While it's true QEMU > >> > doesn't need to manually close the fds for child process as the proper > >> > O_CLOEXEC flag should have been set properly on files with its own > >> > codes, QEMU uses a huge number of 3rd party libraries and we don't > >> > trust them to reliably be using O_CLOEXEC on everything they open. > >> > > >> > Modern Linux and BSDs have the close_range() call we can use to do the > >> > job, and on Linux we have one more way to walk through /proc/self/fd > >> > to complete the task efficiently, which is what qemu_close_range() > >> > does, a new API we add in util/osdep.c. > >> > > >> > V1 link: > >> > https://lore.kernel.org/qemu-devel/[email protected]/ > >> > > >> > Changes in v4: > >> > - add 'first > last' check logic > >> > - reorder the ifdefs logic > >> > - change i to unsigned int type > >> > - use qemu_strtoi() instead of atoi() > >> > - limit last upper value to sysconf(_SC_OPEN_MAX) - 1 > >> > - call sysconf directly instead of using a variable > >> > - put fd on its own line > >> > > >> > Changes in v3: > >> > - fix win32 build failure > >> > - limit the last_fd of qemu_close_range() to sysconf(_SC_OPEN_MAX) > >> > > >> > Changes in v2: > >> > - new patch: "tests/tcg/cris: Fix the coding style" > >> > - new patch: "tests/tcg/cris: Correct the off-by-one error" > >> > - new patch: "util/async-teardown: Fall back to close fds one by one" > >> > - new patch: "util/osdep: Introduce qemu_close_range()" > >> > - new patch: "util/async-teardown: Use qemu_close_range() to close fds" > >> > - Change to use qemu_close_range() to close fds for child process > >> > efficiently > >> > - v1 link: > >> > https://lore.kernel.org/qemu-devel/[email protected]/ > >> > > >> > Bin Meng (4): > >> > tests/tcg/cris: Fix the coding style > >> > tests/tcg/cris: Correct the off-by-one error > >> > util/async-teardown: Fall back to close fds one by one > >> > util/osdep: Introduce qemu_close_range() > >> > > >> > Zhangjin Wu (2): > >> > util/async-teardown: Use qemu_close_range() to close fds > >> > net: tap: Use qemu_close_range() to close fds > >> > > >> > >> Ping for 8.1? > > > > Queued. > > There are review questions open on PATCH 4+5.
Sorry, I missed that. I've dropped them from the queue now. Thanks >
