Re: kern/29360: vfs.generic.usermount and mount(8) general questions

[Thor Lancelot Simon <tls%panix.com@localhost>]

The following reply was made to PR kern/29360; it has been noted by GNATS.

From: Thor Lancelot Simon <tls%panix.com@localhost>
To: Antti Kantee <pooka%cs.hut.fi@localhost>, Manuel Bouyer 
<bouyer%antioche.eu.org@localhost>,
        Elad Efrat <elad%NetBSD.org@localhost>, gnats-bugs%NetBSD.org@localhost,
        tech-kern%NetBSD.org@localhost
Cc: 
Subject: Re: kern/29360: vfs.generic.usermount and mount(8) general
        questions
Date: Sun, 6 Sep 2009 17:21:26 -0400

 On Sun, Sep 06, 2009 at 09:23:19PM +0300, Antti Kantee wrote:
 > 
 > Apparently you can still make the system panic by just mounting a zillion
 > kernfs's (which is just one way to make the kernel run out of memory).
 > I think the problem is that somewhere along the line kmem_alloc(KM_SLEEP)
 > returns NULL.  I remember there being discussions that the caller of
 > kmem_alloc() should always check against NULL return, but that of course
 > makes calling it slightly inconvenient.
 
 Supposedly, allocations with KM_SLEEP won't return NULL, so code can
 safely assume they don't.  I've been told at least once that it is bad
 style to check...!
 
 -- 
 Thor Lancelot Simon                                       
tls%rek.tjls.com@localhost
     "Even experienced UNIX users occasionally enter rm *.* at the UNIX
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