From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43342) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5CHu-0001Ap-FP for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:17:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5CHr-0000KZ-8c for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:17:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35876) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5CHr-0000Jm-0u for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:17:47 -0400 From: Juan Quintela In-Reply-To: <1434450415-11339-8-git-send-email-dgilbert@redhat.com> (David Alan Gilbert's message of "Tue, 16 Jun 2015 11:26:20 +0100") References: <1434450415-11339-1-git-send-email-dgilbert@redhat.com> <1434450415-11339-8-git-send-email-dgilbert@redhat.com> Date: Wed, 17 Jun 2015 14:17:43 +0200 Message-ID: <878ubi5y1k.fsf@neno.neno> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH v7 07/42] ram_debug_dump_bitmap: Dump a migration bitmap as text Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, liang.z.li@intel.com, qemu-devel@nongnu.org, luis@cs.umu.se, amit.shah@redhat.com, pbonzini@redhat.com, david@gibson.dropbear.id.au "Dr. David Alan Gilbert (git)" wrote: > From: "Dr. David Alan Gilbert" > > Useful for debugging the migration bitmap and other bitmaps > of the same format (including the sentmap in postcopy). > > The bitmap is printed to stderr. > Lines that are all the expected value are excluded so the output > can be quite compact for many bitmaps. > > Signed-off-by: Dr. David Alan Gilbert > --- > include/migration/migration.h | 1 + > migration/ram.c | 38 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index 9387c8c..b3a7f75 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -144,6 +144,7 @@ uint64_t xbzrle_mig_pages_cache_miss(void); > double xbzrle_mig_cache_miss_rate(void); > > void ram_handle_compressed(void *host, uint8_t ch, uint64_t size); > +void ram_debug_dump_bitmap(unsigned long *todump, bool expected); > > /** > * @migrate_add_blocker - prevent migration from proceeding > diff --git a/migration/ram.c b/migration/ram.c > index 57368e1..efc215a 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -1051,6 +1051,44 @@ 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; 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 = 128; > + char linebuf[129]; > + > + if (!todump) { > + todump = migration_bitmap; > + } Why? Just alssert that todump!= NULL? > + > + 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' : '.'; Put 1 and 0? Why the dot? > + found = found || (thisbit != expected); > + } > + if (found) { > + linebuf[curb] = '\0'; > + fprintf(stderr, "0x%08" PRIx64 " : %s\n", cur, linebuf); > + } > + } > +} And once here, why are we doing it this way? We have find_first_bit(addr, nbits) and find_first_zero_bit(addr, nbits) and friends? Doiwg the walk by hand looks weird, no? Later, Juan.