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From: Peter Zijlstra <peterz@infradead.org>
To: Kan Liang <kan.liang@linux.intel.com>
Cc: acme@kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org,
	mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
	jolsa@redhat.com, eranian@google.com, ak@linux.intel.com,
	dave.hansen@intel.com, kirill.shutemov@linux.intel.com
Subject: Re: [PATCH V6 01/16] perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE
Date: Mon, 10 Aug 2020 23:35:24 +0200	[thread overview]
Message-ID: <20200810213524.GI3982@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20200810212436.8026-2-kan.liang@linux.intel.com>

On Mon, Aug 10, 2020 at 02:24:21PM -0700, Kan Liang wrote:
> Current perf can report both virtual addresses and physical addresses,
> but not the page size. Without the page size information of the utilized
> page, users cannot decide whether to promote/demote large pages to
> optimize memory usage.
> 
> Add a new sample type for the data page size.
> 
> Current perf already has a facility to collect data virtual addresses.
> A page walker is required to walk the pages tables and calculate the
> page size from a given virtual address.
> 
> On some platforms, e.g., X86, the page walker is invoked in an NMI
> handler. So the page walker must be IRQ-safe and low overhead. Besides,
> the page walker should work for both user and kernel virtual address.
> The existing generic page walker, e.g., walk_page_range_novma(), is a
> little bit complex and doesn't guarantee the IRQ-safe. The follow_page()
> is only for user-virtual address.

s/IRQ/NMI/g

  reply	other threads:[~2020-08-10 21:35 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-10 21:24 [PATCH V6 00/16] Add the page size in the perf record Kan Liang
2020-08-10 21:24 ` [PATCH V6 01/16] perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE Kan Liang
2020-08-10 21:35   ` Peter Zijlstra [this message]
2020-08-10 21:39   ` Peter Zijlstra
2020-08-10 22:36     ` Liang, Kan
2020-08-10 21:47   ` Dave Hansen
2020-08-10 22:38     ` Liang, Kan
2020-08-10 22:47       ` Peter Zijlstra
2020-08-12 13:39         ` Liang, Kan
2020-08-12 13:53           ` Dave Hansen
2020-08-10 21:24 ` [PATCH V6 02/16] perf/x86/intel: Support PERF_SAMPLE_DATA_PAGE_SIZE Kan Liang
2020-08-10 21:40   ` Peter Zijlstra
2020-08-10 22:36     ` Liang, Kan
2020-08-10 21:24 ` [PATCH V6 03/16] perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE Kan Liang
2020-08-10 21:41   ` Peter Zijlstra
2020-08-10 22:37     ` Liang, Kan
2020-08-10 22:44       ` Peter Zijlstra
2020-08-10 21:24 ` [PATCH V6 04/16] tools headers UAPI: Update tools's copy of linux/perf_event.h Kan Liang
2020-08-10 21:24 ` [PATCH V6 05/16] perf record: Support new sample type for data page size Kan Liang
2020-08-10 21:24 ` [PATCH V6 06/16] perf script: Use ULL for enum perf_output_field Kan Liang
2020-08-12 12:21   ` Arnaldo Carvalho de Melo
2020-08-12 13:42     ` Liang, Kan
2020-08-10 21:24 ` [PATCH V6 07/16] perf script: Support data page size Kan Liang
2020-08-10 21:24 ` [PATCH V6 08/16] perf sort: Add sort option for " Kan Liang
2020-08-10 21:24 ` [PATCH V6 09/16] perf mem: Factor out a function to generate sort order Kan Liang
2020-08-10 21:24 ` [PATCH V6 10/16] perf mem: Clean up output format Kan Liang
2020-08-10 21:24 ` [PATCH V6 11/16] perf mem: Support data page size Kan Liang
2020-08-10 21:24 ` [PATCH V6 12/16] perf test: Add test case for PERF_SAMPLE_DATA_PAGE_SIZE Kan Liang
2020-08-10 21:24 ` [PATCH V6 13/16] perf tools: Add support for PERF_SAMPLE_CODE_PAGE_SIZE Kan Liang
2020-08-10 21:24 ` [PATCH V6 14/16] perf script: " Kan Liang
2020-08-10 21:24 ` [PATCH V6 15/16] perf report: " Kan Liang
2020-08-10 21:24 ` [PATCH V6 16/16] perf test: Add test case " Kan Liang

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