From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
Mike Galbraith <efault@gmx.de>
Subject: Re: [PATCH] mm/zsmalloc: Replace bit spinlock and get_cpu_var() usage.
Date: Thu, 30 Sep 2021 08:42:59 +0200 [thread overview]
Message-ID: <20210930064259.dqvogmk42zporwa2@linutronix.de> (raw)
In-Reply-To: <YVS50ZXqCk+SS71K@google.com>
On 2021-09-29 12:09:05 [-0700], Minchan Kim wrote:
> First of all, thanks for the patch, Sebastian.
>
> The zsmalloc is usually used with swap and swap size is normally several
> GB above. Thus, adding per-page spinlock is rather expensive so I'd like to
> consider the approach as last resort. About the lock contention, it's rare
> so spinlock wouldn't help it much.
>
> Let me try changing the bit lock into sleepable lock in PREEMPT_RT with
> bigger granuarity.
Okay, thank you. spinlock_t has always four bytes without lockdep so you
could fit twice as many locks compared to a long on 64bit ;)
Sebastian
prev parent reply other threads:[~2021-09-30 6:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 17:01 [PATCH] mm: Disable zsmalloc on PREEMPT_RT Sebastian Andrzej Siewior
2021-09-23 23:06 ` Minchan Kim
2021-09-24 7:08 ` Sebastian Andrzej Siewior
2021-09-28 8:44 ` [PATCH] mm/zsmalloc: Replace bit spinlock and get_cpu_var() usage Sebastian Andrzej Siewior
2021-09-28 22:47 ` Andrew Morton
2021-09-29 2:11 ` Mike Galbraith
2021-09-29 7:23 ` Sebastian Andrzej Siewior
2021-09-29 19:09 ` Minchan Kim
2021-09-30 6:42 ` Sebastian Andrzej Siewior [this message]
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