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From: "David Wang" <00107082@163.com>
To: "Kent Overstreet" <kent.overstreet@linux.dev>
Cc: "Suren Baghdasaryan" <surenb@google.com>,
	akpm@linux-foundation.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] alloc_tag: avoid mem alloc and iter reset when reading allocinfo
Date: Thu, 8 May 2025 11:35:11 +0800 (CST)	[thread overview]
Message-ID: <1ed4c8f7.3e12.196adf621a2.Coremail.00107082@163.com> (raw)
In-Reply-To: <y6egptcxlbzgboykjorh3syxwy4wu37eolmjtwuwu36gtbfhgf@o3o34qii4gmq>



At 2025-05-08 11:31:12, "Kent Overstreet" <kent.overstreet@linux.dev> wrote:
>On Thu, May 08, 2025 at 11:06:35AM +0800, David Wang wrote:
>> Thanks for the feedback~
>> I agree that memory allocation normally dose not take major part of a profiling report,
>> even profiling a fio test, kmem_cache_alloc only takes ~1% perf samples.
>> 
>> I don't know why I have this "the less memory allocation, the better' mindset,  maybe
>> I was worrying about memory fragmentation, or something else I  learned on some "textbook",
>> To be honest, I  have never had real experience with those worries....
>
>It's a common bias. "Memory allocations" take up a lot of conceptual
>space in our heads, and generally for good reason - i.e. handling memory
>allocation errors is often a major concern, and you do always want to be
>aware of memory layout.
>
>But this can turn into an aversion that's entirely disproportionate -
>e.g. using linked linked lists and fixed size arrays in ways that are
>entirely inappropriate, instead of vectors and other better data
>structures; good data structures always require allocations.
>
>Profile, profile, profile, and remember your basic CS (big O notation) -
>90% of the time, simple code with good big O running time is all you
>need.

copy that~!

Thanks
David

  reply	other threads:[~2025-05-08  3:35 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-07 17:55 [PATCH] alloc_tag: avoid mem alloc and iter reset when reading allocinfo David Wang
2025-05-07 18:19 ` David Wang
2025-05-07 23:42   ` [PATCH] " Suren Baghdasaryan
2025-05-08  0:01     ` Kent Overstreet
2025-05-08  3:06       ` David Wang
2025-05-08  3:31         ` Kent Overstreet
2025-05-08  3:35           ` David Wang [this message]
2025-05-08  4:07             ` Kent Overstreet
2025-05-08  5:51               ` David Wang
2025-05-08 13:33                 ` Kent Overstreet
2025-05-08 16:24                   ` David Wang
2025-05-08 16:34                     ` Kent Overstreet
2025-05-08 16:58                       ` David Wang
2025-05-08 17:17                         ` David Wang
2025-05-08 17:26                           ` Kent Overstreet
2025-05-08  2:24     ` David Wang
2025-05-07 23:36 ` Suren Baghdasaryan
2025-05-08  3:10   ` David Wang
2025-05-08 15:32   ` David Wang
2025-05-08 21:41     ` Suren Baghdasaryan
2025-05-09  5:51 ` [PATCH 1/2] alloc_tag: add timestamp to codetag iterator David Wang
2025-05-09 16:10   ` Suren Baghdasaryan
2025-05-09 16:16     ` David Wang
2025-05-09  5:53 ` [PATCH 2/2] alloc_tag: keep codetag iterator cross read() calls David Wang
2025-05-09 17:34   ` Suren Baghdasaryan
2025-05-09 17:45     ` David Wang
2025-05-09 17:38 ` [PATCH v2 1/2] alloc_tag: add sequence number for module and iterator David Wang
2025-05-09 19:25   ` Suren Baghdasaryan
2025-06-09  6:42     ` [PATCH v3 " David Wang
2025-06-09 16:41       ` Suren Baghdasaryan
2025-05-09 17:39 ` [PATCH v2 2/2] alloc_tag: keep codetag iterator active between read() calls David Wang
2025-05-09 18:33   ` Tim Chen
2025-05-09 19:36     ` Suren Baghdasaryan
2025-05-09 19:46       ` Tim Chen
2025-05-09 20:46         ` Suren Baghdasaryan
2025-05-09 21:15           ` Suren Baghdasaryan
2025-05-10  3:10             ` David Wang
2025-05-10  3:30               ` Suren Baghdasaryan
2025-05-10  3:58                 ` David Wang
2025-05-10  4:03                   ` Suren Baghdasaryan
2025-06-09  6:44                     ` [PATCH v3 2/2] alloc_tag: keep codetag iterator active between read() David Wang
2025-06-10 16:22                       ` Suren Baghdasaryan
2025-05-10  3:35         ` [PATCH v2 2/2] alloc_tag: keep codetag iterator active between read() calls David Wang
2025-05-10  3:25     ` David Wang

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