From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederik Deweerdt Subject: Re: [PATCH][RFC] add MAP_UNLOCKED mmap flag Date: Tue, 6 Oct 2009 10:09:08 +0000 Message-ID: <20091006100908.GB6650@gambetta> References: <20091006095111.GG9832@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20091006095111.GG9832@redhat.com> Sender: owner-linux-mm@kvack.org To: Gleb Natapov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org Hello Gleb, On Tue, Oct 06, 2009 at 11:51:11AM +0200, Gleb Natapov wrote: > If application does mlockall(MCL_FUTURE) it is no longer possible to > mmap file bigger than main memory or allocate big area of anonymous > memory. Sometimes it is desirable to lock everything related to program > execution into memory, but still be able to mmap big file or allocate > huge amount of memory and allow OS to swap them on demand. MAP_UNLOCKED > allows to do that. > > Signed-off-by: Gleb Natapov > diff --git a/include/asm-generic/mman.h b/include/asm-generic/mman.h > index 32c8bd6..0ab4c74 100644 > --- a/include/asm-generic/mman.h > +++ b/include/asm-generic/mman.h > @@ -12,6 +12,7 @@ > #define MAP_NONBLOCK 0x10000 /* do not block on IO */ > #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ > +#define MAP_UNLOKED 0x80000 /* pages are unlocked */ ^^^ You're missing a 'C' here and below. Also '/* force page unlocking */' seems a better comment? Regards, Frederik > > #define MCL_CURRENT 1 /* lock all current mappings */ > #define MCL_FUTURE 2 /* lock all future mappings */ > diff --git a/mm/mmap.c b/mm/mmap.c > index 73f5e4b..7c2abdb 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -985,6 +985,9 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, > if (!can_do_mlock()) > return -EPERM; > > + if (flags & MAP_UNLOKED) > + vm_flags &= ~VM_LOCKED; > + > /* mlock MCL_FUTURE? */ > if (vm_flags & VM_LOCKED) { > unsigned long locked, lock_limit; > -- > Gleb. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org