RE: [PATCH 1/2] perf: Add closing sibling events' file descriptors

From: David Laight
Date: Tue Aug 11 2020 - 10:47:10 EST

From: Andi Kleen
> On Mon, Aug 10, 2020 at 10:36:32PM +0200, Peter Zijlstra wrote:
> > On Mon, Aug 10, 2020 at 07:45:18AM -0700, Andi Kleen wrote:
> >
> > > Unfortunately we're kind of stuck with the old NFILE=1024 default
> > > even though it makes little sense on modern servers.
> >
> > Why can't that be changed? It seems to me all of userspace changes all
> > the time; heck that system-doofus thing flushed 20+ years of sysadmin
> > experience down the drain, just cause. Why can't we up a file limit?
> We could try, but I believe it's hard coded in various places outside
> the kernel.

The place it really bites is select().
Although the kernel supports large bitmaps glibc doesn't.
The random bit overwrites are a PITA to debug.


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