From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id A6CA66B004A for ; Wed, 15 Sep 2010 10:46:51 -0400 (EDT) Received: by yxk8 with SMTP id 8so125341yxk.14 for ; Wed, 15 Sep 2010 07:46:50 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4C90A6C7.9050607@redhat.com> References: <20100915104855.41de3ebf@lilo> <4C90A6C7.9050607@redhat.com> From: Bryan Donlan Date: Wed, 15 Sep 2010 23:46:09 +0900 Message-ID: Subject: Re: [RFC][PATCH] Cross Memory Attach Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Avi Kivity Cc: Christopher Yeoh , linux-kernel@vger.kernel.org, Linux Memory Management List , Ingo Molnar List-ID: On Wed, Sep 15, 2010 at 19:58, Avi Kivity wrote: > Instead of those two syscalls, how about a vmfd(pid_t pid, ulong start, > ulong len) system call which returns an file descriptor that represents a > portion of the process address space. =A0You can then use preadv() and > pwritev() to copy memory, and io_submit(IO_CMD_PREADV) and > io_submit(IO_CMD_PWRITEV) for asynchronous variants (especially useful wi= th > a dma engine, since that adds latency). > > With some care (and use of mmu_notifiers) you can even mmap() your vmfd a= nd > access remote process memory directly. Rather than introducing a new vmfd() API for this, why not just add implementations for these more efficient operations to the existing /proc/$pid/mem interface? -- 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