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From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Vitaly Wool <vitaly.wool@konsulko.com>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Mike Galbraith <efault@gmx.de>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        Barry Song <song.bao.hua@hisilicon.com>,
        Minchan Kim <minchan@kernel.org>,
        NitinGupta <ngupta@vflare.org>
Subject: Re: [PATCH] zsmalloc: do not use bit_spin_lock
Message-ID: <20210114161707.wfgbxi2rppoobfo7@linutronix.de>
References: <18669bd607ae9efbf4e00e36532c7aa167d0fa12.camel@gmx.de>
 <20201220002228.38697-1-vitaly.wool@konsulko.com>
 <20201220011835.GU15600@casper.infradead.org>
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On 2020-12-20 08:21:37 [+0100], Vitaly Wool wrote:
> Not really because bit spinlock leaves preemption disabled.

It leaves it disabled for a reason. Now you just spin until the original
context gets back on the CPU. On UP with preemption, if the "lock owner"
gets preempted, the next lock attempt will lock-up the system.

Sebastian