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From: Juergen Gross <jgross@suse.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
	tglx@linutronix.de, linux-kernel@vger.kernel.org,
	joro@8bytes.org, boris.ostrovsky@oracle.com, x86@kernel.org,
	mbenes@suse.com, rostedt@goodmis.org, dvyukov@google.com,
	elver@google.com
Subject: Re: [PATCH v2 01/24] x86/xen: Mark cpu_bringup_and_idle() as dead_end_function
Date: Mon, 30 Aug 2021 09:56:02 +0200	[thread overview]
Message-ID: <5e879610-6cee-00ac-9959-75f667c1967c@suse.com> (raw)
In-Reply-To: <20210830074834.GE4353@worktop.programming.kicks-ass.net>


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On 30.08.21 09:48, Peter Zijlstra wrote:
> On Mon, Aug 30, 2021 at 07:55:02AM +0200, Juergen Gross wrote:
>>>> From: Josh Poimboeuf <jpoimboe@redhat.com>
>>>> Subject: [PATCH] x86/xen: Move hypercall_page to top of the file
>>>>
>>>> Because hypercall_page is page-aligned, the assembler inexplicably adds
>>>> an unreachable jump from after the end of the previous code to the
>>>> beginning of hypercall_page.
>>>>
>>>> That confuses objtool, understandably.  It also creates significant text
>>>> fragmentation.  As a result, much of the object file is wasted text
>>>> (nops).
>>>>
>>>> Move hypercall_page to the beginning of the file to both prevent the
>>>> text fragmentation and avoid the dead jump instruction.
>>>>
>>>> $ size /tmp/head_64.before.o /tmp/head_64.after.o
>>>>      text       data        bss        dec        hex    filename
>>>>     10924     307252       4096     322272      4eae0
>>>> /tmp/head_64.before.o
>>>>      6823     307252       4096     318171      4dadb
>>>> /tmp/head_64.after.o
>>>>
>>>> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com
>>>
>>> Reviewed-by: Juergen Gross <jgross@suse.com>
>>
>> Umm, will this be carried through the tip tree, or shall I take it in
>> the xen tree?
> 
> I have it in the whole x86/objtool/paravirt series. I you want it in the
> Xen tree, I'll be happy to drop it from there, although I hope to get
> all that merged this cycles somewhere.
> 

Okay, I think it is better kept in your series then.


Juergen

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  reply	other threads:[~2021-08-30  7:56 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-24  9:40 [PATCH v2 00/24] objtool/x86: noinstr vs PARAVIRT Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 01/24] x86/xen: Mark cpu_bringup_and_idle() as dead_end_function Peter Zijlstra
2021-06-24 10:49   ` Juergen Gross
2021-06-30 11:47   ` Miroslav Benes
2021-08-20 19:22   ` Josh Poimboeuf
2021-08-20 19:31     ` Josh Poimboeuf
2021-08-23  8:40       ` Juergen Gross
2021-08-30  5:55         ` Juergen Gross
2021-08-30  7:48           ` Peter Zijlstra
2021-08-30  7:56             ` Juergen Gross [this message]
2021-09-15 15:49       ` [tip: objtool/core] x86/xen: Move hypercall_page to top of the file tip-bot2 for Josh Poimboeuf
2021-09-15 15:49   ` [tip: objtool/core] x86/xen: Mark cpu_bringup_and_idle() as dead_end_function tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 02/24] objtool: Introduce CFI hash Peter Zijlstra
2021-06-30 12:45   ` Miroslav Benes
2021-07-01  8:35     ` Peter Zijlstra
2021-07-01  8:53       ` Miroslav Benes
2021-08-20 22:27   ` Josh Poimboeuf
2021-08-25 10:13     ` Peter Zijlstra
2021-08-25 12:49       ` Peter Zijlstra
2021-08-25 10:15     ` Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 03/24] objtool: Handle __sanitize_cov*() tail calls Peter Zijlstra
2021-06-25 11:05   ` Marco Elver
2021-06-28  9:07     ` Peter Zijlstra
2021-06-25 13:38   ` Steven Rostedt
2021-06-26  8:18     ` Peter Zijlstra
2021-06-29  1:07       ` Steven Rostedt
2021-08-20 23:17   ` Josh Poimboeuf
2021-08-25 10:19     ` Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 04/24] x86/kvm: Always inline sev_*guest() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 05/24] x86/kvm: Always inline vmload() / vmsave() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 06/24] x86: Always inline context_tracking_guest_enter() Peter Zijlstra
2021-08-20 23:22   ` Josh Poimboeuf
2021-08-20 23:34     ` Josh Poimboeuf
2021-08-25 12:16       ` Peter Zijlstra
     [not found]         ` <YSZxtBHNJzoUbqdE@ravnborg.org>
2021-08-26  4:10           ` Josh Poimboeuf
2021-08-25 13:38       ` Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 07/24] x86/kvm: Always inline to_svm() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 08/24] x86/kvm: Always inline evmcs_write64() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 09/24] x86: Always inline ip_within_syscall_gap() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 10/24] x86/sev: Fix noinstr for vc_ghcb_invalidate() Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 11/24] locking/lockdep: Avoid RCU-induced noinstr fail Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 12/24] x86/paravirt: Mark arch_local_irq_*() __always_inline Peter Zijlstra
2021-06-24 10:51   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 13/24] x86/paravirt: Use PVOP_* for paravirt calls Peter Zijlstra
2021-06-24 10:52   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 14/24] x86/xen: Make read_cr2() noinstr Peter Zijlstra
2021-06-24 10:55   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 15/24] x86/xen: Make write_cr2() noinstr Peter Zijlstra
2021-06-24 10:56   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 16/24] x86/xen: Make get_debugreg() noinstr Peter Zijlstra
2021-06-24 10:57   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 17/24] x86/xen: Make set_debugreg() noinstr Peter Zijlstra
2021-06-24 10:59   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 18/24] x86/xen: Make save_fl() noinstr Peter Zijlstra
2021-06-24 11:07   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 19/24] x86/xen: Make hypercall_page noinstr Peter Zijlstra
2021-06-24 11:08   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 20/24] x86/xen: Make irq_enable() noinstr Peter Zijlstra
2021-06-24 11:09   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 21/24] x86/xen: Make irq_disable() noinstr Peter Zijlstra
2021-06-24 11:10   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 22/24] x86/xen: Mark xen_force_evtchn_callback() noinstr Peter Zijlstra
2021-06-24 11:11   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 23/24] x86/xen: Rework the xen_{cpu,irq,mmu}_ops[] arrays Peter Zijlstra
2021-06-24 12:12   ` Juergen Gross
2021-09-15 15:49   ` [tip: objtool/core] x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24  9:41 ` [PATCH v2 24/24] objtool: Support pv_opsindirect calls for noinstr Peter Zijlstra
2021-09-15 15:49   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-09-17 12:58   ` tip-bot2 for Peter Zijlstra
2021-06-24 13:05 ` [PATCH v2 00/24] objtool/x86: noinstr vs PARAVIRT Steven Rostedt

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