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Re: [Qemu-devel] [PATCH v4 18/47] ram_debug_dump_bitmap: Dump a migratio
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [PATCH v4 18/47] ram_debug_dump_bitmap: Dump a migration bitmap as text |
Date: |
Mon, 3 Nov 2014 14:58:21 +1100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Fri, Oct 03, 2014 at 06:47:24PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> Misses out lines that are all the expected value so the output
> can be quite compact depending on the circumstance.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
> arch_init.c | 39 +++++++++++++++++++++++++++++++++++++++
> include/migration/migration.h | 1 +
> 2 files changed, 40 insertions(+)
>
> diff --git a/arch_init.c b/arch_init.c
> index 772de36..6970733 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -769,6 +769,45 @@ static void reset_ram_globals(void)
>
> #define MAX_WAIT 50 /* ms, half buffered_file limit */
>
> +/*
> + * 'expected' is the value you expect the bitmap mostly to be full
> + * of and it won't bother printing lines that are all this value
> + * if 'todump' is null the migration bitmap is dumped.
> + */
> +void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
> +{
> + int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
> +
> + int64_t cur;
> + int64_t linelen = 128l;
I don't think there's any point to the 'l' there. "long" isn't
necessarily correct for an int64_t, and normal type promotion should
get this right anyway.
Assuming the user has a >128 character wide terminal seems a little
obnoxious, too.
> + char linebuf[129];
> +
> + if (!todump) {
> + todump = migration_bitmap;
> + }
> +
> + for (cur = 0; cur < ram_pages; cur += linelen) {
> + int64_t curb;
> + bool found = false;
> + /*
> + * Last line; catch the case where the line length
> + * is longer than remaining ram
> + */
> + if (cur+linelen > ram_pages) {
> + linelen = ram_pages - cur;
> + }
> + for (curb = 0; curb < linelen; curb++) {
> + bool thisbit = test_bit(cur+curb, todump);
> + linebuf[curb] = thisbit ? '1' : '.';
> + found |= (thisbit ^ expected);
I guess this will have the right result with the obvious encoding of a
bool, but I don't think it's conceptually correct. It should be
logical, not bitwise operations so:
found = found || (thisbit != expected);
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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- Re: [Qemu-devel] [PATCH v4 18/47] ram_debug_dump_bitmap: Dump a migration bitmap as text,
David Gibson <=