From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: suravee.suthikulpanit@amd.com, George.Dunlap@eu.citrix.com,
jacob.shin@amd.com, eddie.dong@intel.com,
dietmar.hahn@ts.fujitsu.com, jun.nakajima@intel.com,
xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH v1 01/13] Export hypervisor symbols
Date: Wed, 11 Sep 2013 09:55:18 -0400 [thread overview]
Message-ID: <52307646.4060504@oracle.com> (raw)
In-Reply-To: <52303D1F02000078000F2495@nat28.tlf.novell.com>
On 09/11/2013 03:51 AM, Jan Beulich wrote:
>>>> On 10.09.13 at 17:20, Boris Ostrovsky<boris.ostrovsky@oracle.com> wrote:
>> --- a/xen/arch/x86/Makefile
>> +++ b/xen/arch/x86/Makefile
>> @@ -102,11 +102,11 @@ $(BASEDIR)/common/symbols-dummy.o:
>> $(TARGET)-syms: prelink.o xen.lds $(BASEDIR)/common/symbols-dummy.o
>> $(LD) $(LDFLAGS) -T xen.lds -N prelink.o \
>> $(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
>> - $(NM) -n $(@D)/.$(@F).0 | $(BASEDIR)/tools/symbols >$(@D)/.$(@F).0.S
>> + $(NM) -n $(@D)/.$(@F).0 | $(BASEDIR)/tools/symbols --all-symbols >$(@D)/.$(@F).0.S
> For one I can't see what use data symbols have for performance
> analysis.
They are used by perf, similarly to kallsyms (usually when debug symbols
from
binary are not available)
> And then I'm opposed to growing the symbol table size
> unconditionally for no good reason.
I think I can remove --all-symbols, it is not strictly necessary for
what I plan now for
perf. We may need to add it later, possibly with a config option.
>> --- a/xen/include/public/platform.h
>> +++ b/xen/include/public/platform.h
>> @@ -527,6 +527,26 @@ struct xenpf_core_parking {
>> typedef struct xenpf_core_parking xenpf_core_parking_t;
>> DEFINE_XEN_GUEST_HANDLE(xenpf_core_parking_t);
>>
>> +#define XENPF_get_symbols 61
>> +
>> +#define XENSYMS_SZ 4096
> This doesn't appear to belong into the public interface.
Linux driver needs to know size of the buffer that is passed from
the hypervisir. I suppose I can just use PAGE_SIZE.
>> +struct xenpf_symdata {
>> + /*
>> + * offset into Xen's symbol data and symbol number from
>> + * last call. Used only by Xen.
>> + */
>> + uint64_t xen_offset;
>> + uint64_t xen_symnum;
> I wonder whether that's really a suitable mechanism.
Why do you think this is not suitable?
Linux needs to keep track of position in the symbol table while
it is walking over the file, otherwise we will need to keep the state
in hypervisor which is much less desirable.
>
>> +
>> + /*
>> + * Symbols data, formatted similar to /proc/kallsyms:
>> + * <address> <type> <name>
>> + */
>> + XEN_GUEST_HANDLE(char) buf;
> This is too simplistic: Please use a proper structure here, to allow
> switching the internal symbol table representation (which I have on
> my todo list) without having to mimic old behavior.
I don't think I know what you are referring to here.
-boris
next prev parent reply other threads:[~2013-09-11 13:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-10 15:20 [PATCH v1 00/13] x86/PMU: Xen PMU PV support Boris Ostrovsky
2013-09-10 15:20 ` [PATCH v1 01/13] Export hypervisor symbols Boris Ostrovsky
2013-09-11 7:51 ` Jan Beulich
2013-09-11 13:55 ` Boris Ostrovsky [this message]
2013-09-11 14:12 ` Jan Beulich
2013-09-11 14:57 ` Boris Ostrovsky
2013-09-11 16:01 ` Jan Beulich
2013-09-10 15:20 ` [PATCH v1 02/13] Set VCPU's is_running flag closer to when the VCPU is dispatched Boris Ostrovsky
2013-09-11 7:58 ` Jan Beulich
2013-09-10 15:21 ` [PATCH v1 03/13] x86/PMU: Stop AMD counters when called from vpmu_save_force() Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 04/13] x86/VPMU: Minor VPMU cleanup Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 05/13] intel/VPMU: Clean up Intel VPMU code Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 06/13] x86/PMU: Add public xenpmu.h Boris Ostrovsky
2013-09-11 8:13 ` Jan Beulich
2013-09-11 14:03 ` Boris Ostrovsky
2013-09-11 14:16 ` Jan Beulich
2013-09-11 8:37 ` Ian Campbell
2013-09-10 15:21 ` [PATCH v1 07/13] x86/PMU: Make vpmu not HVM-specific Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 08/13] x86/PMU: Interface for setting PMU mode and flags Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 09/13] x86/PMU: Initialize PMU for PV guests Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 10/13] x86/PMU: Add support for PMU registes handling on " Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 11/13] x86/PMU: Handle PMU interrupts for " Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 12/13] x86/PMU: Save VPMU state for PV guests during context switch Boris Ostrovsky
2013-09-10 15:21 ` [PATCH v1 13/13] x86/PMU: Move vpmu files up from hvm directory Boris Ostrovsky
2013-09-10 15:34 ` [PATCH v1 00/13] x86/PMU: Xen PMU PV support Jan Beulich
2013-09-10 15:47 ` Boris Ostrovsky
2013-09-11 17:01 ` George Dunlap
2013-09-11 18:22 ` Boris Ostrovsky
2013-09-12 9:39 ` George Dunlap
2013-09-12 14:58 ` Boris Ostrovsky
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