From: Andrew Morton <akpm@osdl.org>
To: Chris Wright <chrisw@sous-sol.org>
Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org,
xen-devel@lists.xensource.com, ian.pratt@xensource.com,
Christian.Limpach@cl.cam.ac.uk
Subject: Re: [RFC PATCH 29/35] Add the Xen virtual console driver.
Date: Sat, 13 May 2006 05:27:57 -0700 [thread overview]
Message-ID: <20060513052757.59446e03.akpm@osdl.org> (raw)
In-Reply-To: <20060509085159.285105000@sous-sol.org>
On Tue, 09 May 2006 00:00:29 -0700
Chris Wright <chrisw@sous-sol.org> wrote:
> This provides a bootstrap and ongoing emergency console which is
> intended to be available from very early during boot and at all times
> thereafter, in contrast with alternatives such as UDP-based syslogd,
> or logging in via ssh. The protocol is based on a simple shared-memory
> ring buffer.
>
> ...
>
> +/* The kernel and user-land drivers share a common transmit buffer. */
> +static unsigned int wbuf_size = 4096;
> +#define WBUF_MASK(_i) ((_i)&(wbuf_size-1))
> +static char *wbuf;
> +static unsigned int wc, wp; /* write_cons, write_prod */
> +
> +static int __init xencons_bufsz_setup(char *str)
> +{
> + unsigned int goal;
> + goal = simple_strtoul(str, NULL, 0);
> + while (wbuf_size < goal)
> + wbuf_size <<= 1;
roundup_pow_of_two()
> +/* This lock protects accesses to the common transmit buffer. */
> +static spinlock_t xencons_lock = SPIN_LOCK_UNLOCKED;
DEFINE_SPINLOCK() (entire patchset)
> +
> +static void kcons_write(
> + struct console *c, const char *s, unsigned int count)
> +{
> + int i = 0;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&xencons_lock, flags);
> +
> + while (i < count) {
> + for (; i < count; i++) {
> + if ((wp - wc) >= (wbuf_size - 1))
> + break;
> + if ((wbuf[WBUF_MASK(wp++)] = s[i]) == '\n')
> + wbuf[WBUF_MASK(wp++)] = '\r';
> + }
> +
> + __xencons_tx_flush();
> + }
> +
> + spin_unlock_irqrestore(&xencons_lock, flags);
> +}
hm. You have all that elaborate generate-ringbuffer-code-with-C-macros
stuff in the header file patch, yet this code (blessedly) doesn't use it.
> +static void kcons_write_dom0(
> + struct console *c, const char *s, unsigned int count)
> +{
> + int rc;
> +
> + while ((count > 0) &&
> + ((rc = HYPERVISOR_console_io(
> + CONSOLEIO_write, count, (char *)s)) > 0)) {
> + count -= rc;
> + s += rc;
> + }
> +}
must.. not.. mention.. coding.. style..
next prev parent reply other threads:[~2006-05-13 12:31 UTC|newest]
Thread overview: 189+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-05-09 8:49 [RFC PATCH 00/35] Xen i386 paravirtualization support Chris Wright
2006-05-09 7:00 ` [RFC PATCH 01/35] Add XEN config options and disable unsupported config options Chris Wright
2006-05-09 10:05 ` Adrian Bunk
2006-05-09 11:06 ` Ed Tomlinson
2006-05-09 12:45 ` Christian Limpach
2006-05-09 23:23 ` Chris Wright
2006-05-09 14:47 ` Daniel Walker
2006-05-09 15:16 ` Christian Limpach
2006-05-09 16:00 ` Daniel Walker
2006-05-09 23:25 ` Chris Wright
2006-05-09 16:42 ` Andi Kleen
2006-05-10 15:36 ` [Xen-devel] " Alan Cox
2006-05-10 15:48 ` Christian Limpach
2006-05-09 7:00 ` [RFC PATCH 02/35] Makefile support to build Xen subarch Chris Wright
2006-05-09 7:00 ` [RFC PATCH 03/35] Add Xen interface header files Chris Wright
2006-05-09 14:49 ` Martin J. Bligh
2006-05-09 17:54 ` Christian Limpach
2006-05-09 15:15 ` Christoph Hellwig
2006-05-09 19:35 ` Hollis Blanchard
2006-05-09 19:48 ` [Xen-devel] " Anthony Liguori
2006-05-09 22:34 ` Christoph Hellwig
2006-05-09 22:36 ` Ingo Oeser
2006-05-09 16:06 ` Daniel Walker
2006-05-09 16:18 ` Christian Limpach
2006-05-09 16:29 ` Daniel Walker
2006-05-09 7:00 ` [RFC PATCH 04/35] Hypervisor " Chris Wright
2006-05-09 22:43 ` Ingo Oeser
2006-05-09 23:01 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 05/35] Add sync bitops Chris Wright
2006-05-09 22:56 ` Christoph Lameter
2006-05-09 23:04 ` Andi Kleen
2006-05-09 23:07 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 06/35] Add vmlinuz build target Chris Wright
2006-05-09 7:00 ` [RFC PATCH 07/35] Make LOAD_OFFSET defined by subarch Chris Wright
2006-05-10 23:28 ` Zachary Amsden
2006-05-11 7:47 ` [Xen-devel] " Gerd Hoffmann
2006-05-11 8:51 ` Chris Wright
2006-05-11 9:06 ` Gerd Hoffmann
2006-05-11 16:43 ` Christian Limpach
2006-05-12 6:47 ` [Xen-devel] " Jan Beulich
2006-05-12 8:38 ` Christian Limpach
2006-05-09 7:00 ` [RFC PATCH 08/35] Add Xen-specific memory management definitions Chris Wright
2006-05-09 14:49 ` Martin J. Bligh
2006-05-09 17:44 ` Christian Limpach
2006-05-15 6:44 ` Pete Zaitcev
2006-05-15 7:04 ` Keir Fraser
2006-05-15 8:19 ` Christian Limpach
2006-05-17 16:06 ` Pete Zaitcev
2006-05-18 7:42 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 09/35] Change __FIXADDR_TOP to leave room for the hypervisor Chris Wright
2006-05-09 7:00 ` [RFC PATCH 10/35] Add a new head.S start-of-day file for booting on Xen Chris Wright
2006-05-09 7:00 ` [RFC PATCH 11/35] Add support for Xen to entry.S Chris Wright
2006-05-09 16:51 ` Andi Kleen
2006-05-09 7:00 ` [RFC PATCH 12/35] Add start-of-day setup hooks to subarch Chris Wright
2006-05-09 7:00 ` [RFC PATCH 13/35] Support loading an initrd when running on Xen Chris Wright
2006-05-09 7:00 ` [RFC PATCH 14/35] Subarch support for CPUID instruction Chris Wright
2006-05-09 7:00 ` [RFC PATCH 15/35] subarch support for controlling interrupt delivery Chris Wright
2006-05-09 14:49 ` Martin J. Bligh
2006-05-09 14:55 ` Nick Piggin
2006-05-09 15:51 ` Christian Limpach
2006-05-09 16:02 ` Martin J. Bligh
2006-05-09 16:07 ` Andi Kleen
2006-05-09 16:29 ` Christian Limpach
2006-05-09 16:31 ` Andi Kleen
2006-05-09 20:42 ` Christian Limpach
2006-05-09 21:56 ` Andi Kleen
2006-05-10 10:35 ` Christian Limpach
2006-05-10 10:54 ` Andi Kleen
2006-05-09 21:56 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 16/35] subarch support for interrupt and exception gates Chris Wright
2006-05-09 11:09 ` Andi Kleen
2006-05-09 12:55 ` Christian Limpach
2006-05-13 12:27 ` Andrew Morton
2006-05-15 18:30 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 17/35] Segment register changes for Xen Chris Wright
2006-05-09 7:16 ` Pavel Machek
2006-05-10 20:09 ` Andi Kleen
2006-05-10 20:30 ` Pavel Machek
2006-05-11 10:34 ` Avi Kivity
2006-05-11 10:41 ` Andi Kleen
2006-05-12 0:28 ` [Xen-devel] " Rusty Russell
2006-05-09 16:44 ` Andi Kleen
2006-05-18 20:20 ` Zachary Amsden
2006-05-18 20:41 ` Keir Fraser
2006-05-18 21:26 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 18/35] Support gdt/idt/ldt handling on Xen Chris Wright
2006-05-09 7:21 ` Pavel Machek
2006-05-10 20:23 ` Andi Kleen
2006-05-09 14:49 ` Martin J. Bligh
2006-05-09 18:14 ` Christian Limpach
2006-05-09 18:21 ` Martin Bligh
2006-05-09 7:00 ` [RFC PATCH 19/35] subarch support for control register accesses Chris Wright
2006-05-09 7:00 ` [RFC PATCH 20/35] subarch stack pointer update Chris Wright
2006-05-09 7:00 ` [RFC PATCH 21/35] subarch TLB support Chris Wright
2006-05-09 7:00 ` [RFC PATCH 22/35] subarch suport for idle loop (NO_IDLE_HZ for Xen) Chris Wright
2006-05-09 13:21 ` Andi Kleen
2006-05-09 15:13 ` Christian Limpach
2006-05-09 7:00 ` [RFC PATCH 23/35] Increase x86 interrupt vector range Chris Wright
2006-05-09 7:00 ` [RFC PATCH 24/35] Add support for Xen event channels Chris Wright
2006-05-12 21:41 ` Pavel Machek
2006-05-13 12:27 ` Andrew Morton
2006-05-13 13:02 ` Keir Fraser
2006-05-09 7:00 ` [RFC PATCH 25/35] Add Xen time abstractions Chris Wright
2006-05-09 16:23 ` Daniel Walker
2006-05-09 16:38 ` Christian Limpach
2006-05-09 19:27 ` Adrian Bunk
2006-05-09 21:50 ` Andi Kleen
2006-05-09 23:03 ` Ingo Oeser
2006-05-09 23:09 ` Andi Kleen
2006-05-09 23:13 ` Chris Wright
2006-05-12 21:44 ` Pavel Machek
2006-05-09 7:00 ` [RFC PATCH 26/35] Add Xen subarch reboot support Chris Wright
2006-05-09 17:02 ` Andi Kleen
2006-05-12 21:46 ` Pavel Machek
2006-05-12 21:57 ` Chris Wright
2006-05-09 7:00 ` [RFC PATCH 27/35] Add nosegneg capability to the vsyscall page notes Chris Wright
2006-05-09 7:00 ` [RFC PATCH 28/35] add support for Xen feature queries Chris Wright
2006-05-12 21:56 ` Pavel Machek
2006-05-09 7:00 ` [RFC PATCH 29/35] Add the Xen virtual console driver Chris Wright
2006-05-09 13:26 ` Andi Kleen
2006-05-09 15:03 ` Christian Limpach
2006-05-13 12:27 ` Andrew Morton [this message]
2006-05-13 12:51 ` Nick Piggin
2006-05-13 14:29 ` Andrew Morton
2006-05-13 14:43 ` Nick Piggin
2006-05-09 7:00 ` [RFC PATCH 30/35] Add apply_to_page_range() function Chris Wright
2006-05-09 7:00 ` [RFC PATCH 31/35] Add Xen grant table support Chris Wright
2006-05-09 7:00 ` [RFC PATCH 32/35] Add Xen driver utility functions Chris Wright
2006-05-09 19:48 ` Greg KH
2006-05-09 21:50 ` Andi Kleen
2006-05-09 7:00 ` [RFC PATCH 33/35] Add the Xenbus sysfs and virtual device hotplug driver Chris Wright
2006-05-09 16:06 ` Alexey Dobriyan
2006-05-09 16:28 ` Andi Kleen
2006-05-09 19:40 ` Greg KH
2006-05-09 21:53 ` Chris Wright
2006-05-09 22:01 ` Greg KH
2006-05-09 22:50 ` Chris Wright
2006-05-09 23:43 ` Anthony Liguori
2006-05-09 19:49 ` Greg KH
2006-05-09 19:58 ` Chris Wright
2006-05-13 12:28 ` Andrew Morton
2006-05-09 7:00 ` [RFC PATCH 34/35] Add the Xen virtual network device driver Chris Wright
2006-05-09 11:55 ` [Xen-devel] " Herbert Xu
2006-05-09 12:43 ` Christian Limpach
2006-05-09 13:01 ` Herbert Xu
2006-05-09 13:14 ` Andi Kleen
2006-05-09 13:16 ` Christian Limpach
2006-05-09 13:26 ` Herbert Xu
2006-05-09 14:00 ` Christian Limpach
2006-05-09 14:30 ` David Boutcher
2006-05-09 23:35 ` Chris Wright
2006-05-09 11:58 ` Christoph Hellwig
2006-05-09 23:37 ` Chris Wright
2006-05-09 18:56 ` Stephen Hemminger
2006-05-09 23:39 ` Chris Wright
2006-05-09 20:25 ` Stephen Hemminger
2006-05-09 20:26 ` Keir Fraser
2006-05-09 20:39 ` Stephen Hemminger
2006-05-09 20:46 ` Roland Dreier
2006-05-10 18:28 ` Andi Kleen
2006-05-11 0:33 ` Herbert Xu
2006-05-11 7:49 ` Keir Fraser
2006-05-11 8:04 ` Herbert Xu
2006-05-11 9:47 ` Andi Kleen
2006-05-11 16:18 ` Stephen Hemminger
2006-05-11 16:48 ` Rick Jones
2006-05-11 16:55 ` Stephen Hemminger
2006-05-11 17:30 ` Andi Kleen
2006-05-09 20:32 ` Chris Wright
2006-05-09 22:41 ` [Xen-devel] " Herbert Xu
2006-05-09 23:51 ` Chris Wright
2006-05-10 6:36 ` Keir Fraser
2006-05-09 7:00 ` [RFC PATCH 35/35] Add Xen virtual block " Chris Wright
2006-05-09 12:01 ` Christoph Hellwig
2006-05-09 14:49 ` [RFC PATCH 00/35] Xen i386 paravirtualization support Martin J. Bligh
2006-05-09 15:07 ` Christoph Hellwig
2006-05-09 15:12 ` Martin J. Bligh
2006-05-09 15:20 ` Andi Kleen
2006-05-09 15:22 ` Christoph Hellwig
2006-05-09 15:45 ` Pekka Enberg
2006-05-14 1:35 ` Andrew Morton
2006-05-15 21:01 ` Chris Wright
-- strict thread matches above, loose matches on Subject: below --
2006-03-22 6:30 Chris Wright
2006-03-22 6:31 ` [RFC PATCH 29/35] Add the Xen virtual console driver Chris Wright
2006-03-22 8:43 ` Arjan van de Ven
2006-03-22 9:29 ` Keir Fraser
2006-03-22 14:17 ` Andi Kleen
2006-03-22 16:00 ` Anthony Liguori
2006-03-22 16:07 ` Keir Fraser
2006-03-22 16:14 ` Anthony Liguori
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