Linus proposes to revert an accounting for sops objects in do_semtimedop() because it's really just a temporary buffer for a single semtimedop() system call.
This object can consume up to 2 pages, syscall is sleeping one, size and duration can be controlled by user, and this allocation can be repeated by many thread at the same time. However Shakeel Butt pointed that there are much more popular objects with the same life time and similar memory consumption, the accounting of which was decided to be rejected for performance reasons. In addition, any usual task consumes much more accounted memory, so 2 pages of this temporal buffer can be safely ignored. Link: https://patchwork.kernel.org/project/linux-fsdevel/patch/[email protected]/ [backport of upstream patch version] Link: https://lore.kernel.org/all/[email protected]/ Signed-off-by: Vasily Averin <[email protected]> --- ipc/sem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/sem.c b/ipc/sem.c index 437f2e5..274a2bc 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -1797,7 +1797,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, if (nsops > ns->sc_semopm) return -E2BIG; if (nsops > SEMOPM_FAST) { - sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL_ACCOUNT); + sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL); if (sops == NULL) return -ENOMEM; } -- 1.8.3.1 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
