From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: Arun KS <arunks@codeaurora.org>
Cc: keescook@chromium.org, khlebnikov@yandex-team.ru,
minchan@kernel.org, getarunks@gmail.com,
gregkh@linuxfoundation.org, akpm@linux-foundation.org,
mhocko@kernel.org, vbabka@suse.cz, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, vatsa@codeaurora.org, willy@infradead.org
Subject: Re: [PATCH v5 2/4] mm: convert zone->managed_pages to atomic variable
Date: Wed, 14 Nov 2018 19:21:54 +0000 [thread overview]
Message-ID: <20181114192154.cf2kz5pqcokpzpyt@soleen.tm1wkky2jk1uhgkn0ivaxijq1c.bx.internal.cloudapp.net> (raw)
In-Reply-To: <1542090790-21750-3-git-send-email-arunks@codeaurora.org>
On 18-11-13 12:03:08, Arun KS wrote:
> totalram_pages, zone->managed_pages and totalhigh_pages updates
> are protected by managed_page_count_lock, but readers never care
> about it. Convert these variables to atomic to avoid readers
> potentially seeing a store tear.
>
> This patch converts zone->managed_pages. Subsequent patches will
> convert totalram_panges, totalhigh_pages and eventually
> managed_page_count_lock will be removed.
>
> Main motivation was that managed_page_count_lock handling was
> complicating things. It was discussed in length here,
> https://lore.kernel.org/patchwork/patch/995739/#1181785
> So it seemes better to remove the lock and convert variables
> to atomic, with preventing poteintial store-to-read tearing as
> a bonus.
>
> Suggested-by: Michal Hocko <mhocko@suse.com>
> Suggested-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Arun KS <arunks@codeaurora.org>
> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> Acked-by: Michal Hocko <mhocko@suse.com>
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
next prev parent reply other threads:[~2018-11-14 19:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 6:33 [PATCH v5 0/4] mm: convert totalram_pages, totalhigh_pages and managed pages to atomic Arun KS
2018-11-13 6:33 ` [PATCH v5 1/4] mm: reference totalram_pages and managed_pages once per function Arun KS
2018-11-13 14:52 ` David Hildenbrand
2018-11-14 19:20 ` Pavel Tatashin
2018-11-13 6:33 ` [PATCH v5 2/4] mm: convert zone->managed_pages to atomic variable Arun KS
2018-11-13 14:55 ` David Hildenbrand
2018-11-14 19:21 ` Pavel Tatashin [this message]
2018-11-13 6:33 ` [PATCH v5 3/4] mm: convert totalram_pages and totalhigh_pages variables to atomic Arun KS
2018-11-14 19:23 ` Pavel Tatashin
2018-11-13 6:33 ` [PATCH v5 4/4] mm: Remove managed_page_count spinlock Arun KS
2018-11-14 19:23 ` Pavel Tatashin
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