From: Roland McGrath While looking into the issues Jeremy had with the RLIMIT_SIGPENDING limit, it occurred to me that the normal setting of this limit is bizarrely low. The initial hard limit setting (MAX_SIGPENDING) was taken from the old max_queued_signals parameter, which was for the entire system in aggregate. But even as a per-user limit, the 1024 value is incongruously low for this. On my machine, RLIMIT_NPROC allows me 8192 processes, but only 1024 queued signals, i.e. fewer even than one pending signal in each process. (To me, this really puts in doubt the sensibility of using a per-user limit for this rather than a per-process one, i.e. counted in sighand_struct or signal_struct, which could have a much smaller reasonable value. I don't recall the rationale for making this new limit per-user in the first place.) This patch sets the default RLIMIT_SIGPENDING limit at boot time, using the calculation that decides the default RLIMIT_NPROC limit. This uses the same value for those two limits, which I think is still pretty conservative on the RLIMIT_SIGPENDING value. Signed-off-by: Roland McGrath Signed-off-by: Andrew Morton --- 25-akpm/include/asm-generic/resource.h | 2 +- 25-akpm/include/linux/signal.h | 2 -- 25-akpm/kernel/fork.c | 2 ++ 3 files changed, 3 insertions(+), 3 deletions(-) diff -puN include/asm-generic/resource.h~set-rlimit_sigpending-limit-based-on-rlimit_nproc include/asm-generic/resource.h --- 25/include/asm-generic/resource.h~set-rlimit_sigpending-limit-based-on-rlimit_nproc 2005-02-24 19:47:33.000000000 -0800 +++ 25-akpm/include/asm-generic/resource.h 2005-02-24 19:47:33.000000000 -0800 @@ -79,7 +79,7 @@ [RLIMIT_MEMLOCK] = { MLOCK_LIMIT, MLOCK_LIMIT }, \ [RLIMIT_AS] = { RLIM_INFINITY, RLIM_INFINITY }, \ [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \ - [RLIMIT_SIGPENDING] = { MAX_SIGPENDING, MAX_SIGPENDING }, \ + [RLIMIT_SIGPENDING] = { 0, 0 }, \ [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \ } diff -puN include/linux/signal.h~set-rlimit_sigpending-limit-based-on-rlimit_nproc include/linux/signal.h --- 25/include/linux/signal.h~set-rlimit_sigpending-limit-based-on-rlimit_nproc 2005-02-24 19:47:33.000000000 -0800 +++ 25-akpm/include/linux/signal.h 2005-02-24 19:47:33.000000000 -0800 @@ -8,8 +8,6 @@ #ifdef __KERNEL__ -#define MAX_SIGPENDING 1024 - /* * Real Time signals may be queued. */ diff -puN kernel/fork.c~set-rlimit_sigpending-limit-based-on-rlimit_nproc kernel/fork.c --- 25/kernel/fork.c~set-rlimit_sigpending-limit-based-on-rlimit_nproc 2005-02-24 19:47:33.000000000 -0800 +++ 25-akpm/kernel/fork.c 2005-02-24 19:47:33.000000000 -0800 @@ -129,6 +129,8 @@ void __init fork_init(unsigned long memp init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2; init_task.signal->rlim[RLIMIT_NPROC].rlim_max = max_threads/2; + init_task.signal->rlim[RLIMIT_SIGPENDING] = + init_task.signal->rlim[RLIMIT_NPROC]; } static struct task_struct *dup_task_struct(struct task_struct *orig) _