Messages in this thread | | | Date | Sun, 06 Apr 2014 08:42:02 +0200 | From | Manfred Spraul <> | Subject | Re: [PATCH] ipc,shm: disable shmmax and shmall by default |
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Hi,
On 04/05/2014 08:24 PM, KOSAKI Motohiro wrote: > On Fri, Apr 4, 2014 at 1:00 AM, Davidlohr Bueso <davidlohr@hp.com> wrote: >> I don't think it makes much sense to set unlimited for both 0 and >> ULONG_MAX, that would probably just create even more confusion. I agree. Unlimited was INT_MAX since 0.99.10 and ULONG_MAX since 2.3.39 (with proper backward compatibility for user space).
Adding a second value for unlimited just creates confusion. >> But then again, we shouldn't even care about breaking things with shmmax >> or shmall with 0 value, it just makes no sense from a user PoV. shmmax >> cannot be 0 unless there's an overflow, which voids any valid cases, and >> thus shmall cannot be 0 either as it would go against any values set for >> shmmax. I think it's safe to ignore this. > Agreed. > IMHO, until you find out any incompatibility issue of this, we don't > need the switch > because we can't make good workaround for that. I'd suggest to merge your patch > and see what happen. I disagree: - "shmctl(,IPC_INFO,&buf); if (my_memory_size > buf.shmmax) perror("change shmmax");" worked correctly since 0.99.10. I don't think that merging the patch and seeing what happens is the right approach. - setting shmmax by default to ULONG_MAX is the perfect workaround.
What reasons are there against the one-line patch? > > -#define SHMMAX 0x2000000 /* max shared seg size (bytes) */ > +#define SHMMAX ULONG_MAX /* max shared seg size (bytes) */ >
-- Manfred
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