linux-kernel - Could MADV_REMOVE work with hugetlbfs?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20111109212737.35z~@nicemice.net>
Date:	Wed, 9 Nov 2011 21:48:26 +0000
From:	"Adam M. Costello" <linux-kernel.amc+0+@...emice.net>
To:	linux-kernel@...r.kernel.org
Subject: Could MADV_REMOVE work with hugetlbfs?

madvise(MADV_REMOVE) punches a hole in a file (via truncate_range()).
It's the only way (as far as I know) to return an arbitrary page of
shared memory to the system.  It's supported by tmpfs, but not by
hugetlbfs.

So a regular page of shared memory (from shmget() or from mmap() on
a tmpfs file) can be returned, but huge page of shared memory (from
shmget(SHM_HUGETLB) or from mmap() on a hugetlbfs file) cannot be
returned.

Has anyone thought about adding support for truncate_range and
MADV_REMOVE to hugetlbfs?  How hard would that be?

Thanks,
AMC
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/