I seem to have mis-sent v3. Trying again with same patches after fixing the message id for the cover letter. I hope the duplicates that are thus created don't inconvenience people too much. If they do, I apologize. I have pared down the Cc list to reduce the noise. sched maintainers are Cc'd on all patches since that's the tree I aim for with these patches. This improves the might_fault annotations used by uaccess routines: 1. The only reason uaccess routines might sleep is if they fault. Make this explicit for all architectures. 2. a voluntary preempt point in uaccess functions means compiler can't inline them efficiently, this breaks assumptions that they are very fast and small that e.g. net code seems to make. remove this preempt point so behaviour matches what callers assume. 3. Accesses (e.g through socket ops) to kernel memory with KERNEL_DS like net/sunrpc does will never sleep. Remove an unconditinal might_sleep in the inline might_fault in kernel.h (used when PROVE_LOCKING is not set). 4. Accesses with pagefault_disable return EFAULT but won't cause caller to sleep. Check for that and avoid might_sleep when PROVE_LOCKING is set. I'd like these changes to go in for 3.11: besides a general benefit of improved consistency and performance, I would also like them for the vhost driver where we want to call socket ops under a spinlock, and fall back on slower thread handler on error. If the changes look good, would sched maintainers please consider merging them through sched/core because of the interaction with the scheduler? Please review, and consider for 3.11. Note on arch code updates: I tested x86_64 code. Other architectures were build-tested. I don't have cross-build environment for arm64, tile, microblaze and mn10300 architectures. arm64 and tile got acks. The arch changes look generally safe enough but would appreciate review/acks from arch maintainers. core changes naturally need acks from sched maintainers. Version 1 of this change was titled x86: uaccess s/might_sleep/might_fault/ Changes from v2: add a patch removing a colunatry preempt point in uaccess functions when PREEMPT_VOLUNATRY is set. Addresses comments by Arnd Bergmann, and Peter Zijlstra. comment on future possible simplifications in the git log for the powerpc patch. Addresses a comment by Arnd Bergmann. Changes from v1: add more architectures fix might_fault() scheduling differently depending on CONFIG_PROVE_LOCKING, as suggested by Ingo Michael S. Tsirkin (11): asm-generic: uaccess s/might_sleep/might_fault/ arm64: uaccess s/might_sleep/might_fault/ frv: uaccess s/might_sleep/might_fault/ m32r: uaccess s/might_sleep/might_fault/ microblaze: uaccess s/might_sleep/might_fault/ mn10300: uaccess s/might_sleep/might_fault/ powerpc: uaccess s/might_sleep/might_fault/ tile: uaccess s/might_sleep/might_fault/ x86: uaccess s/might_sleep/might_fault/ kernel: drop voluntary schedule from might_fault kernel: uaccess in atomic with pagefault_disable arch/arm64/include/asm/uaccess.h | 4 ++-- arch/frv/include/asm/uaccess.h | 4 ++-- arch/m32r/include/asm/uaccess.h | 12 ++++++------ arch/microblaze/include/asm/uaccess.h | 6 +++--- arch/mn10300/include/asm/uaccess.h | 4 ++-- arch/powerpc/include/asm/uaccess.h | 16 ++++++++-------- arch/tile/include/asm/uaccess.h | 2 +- arch/x86/include/asm/uaccess_64.h | 2 +- include/asm-generic/uaccess.h | 10 +++++----- include/linux/kernel.h | 7 ++----- mm/memory.c | 10 +++++++--- 11 files changed, 39 insertions(+), 38 deletions(-) -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
