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charset="UTF-8" X-Rspamd-Queue-Id: 5018480009 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 9w3edh3cmrfccot9tezwq3suu1n67uwh X-HE-Tag: 1705138259-456363 X-HE-Meta: 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 cj9Hm9c/ zJbcWWBCwXFgQyBoULPtpXtbVqCia2FetX9kslmQu5ETlk0nI98Nyq5Lo+7i7ny3AtHMd/IL+jhqzvR2iUQ96pZn7pPVioDLRK/hs32F2xoUqkD8RkWGZKvhPHtd7QldVpCq7odx0FObyoRpLgMtzomLVOyf0dgFyKCwFvUsuFIkL8UgtG2LsdCgkdWad0YUE8gecO8VeTd3Av54mbDPBm8wuFtMFK/KQNn6gztsn6ATIVaLtWrIftxib1sSvAAj7X4vTlhIWgm/8Hc/fiu5ihSGfb4L2fZ5HUchEmTU2injFnLpX4rW+cO1qZ/EgFw2oPdy94aH6NyIB7kQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, 13 Jan 2024 at 10:23, Marco Elver wrote: > > On Sat, 13 Jan 2024 at 10:19, Andi Kleen wrote: > > > > On Sat, Jan 13, 2024 at 10:12:21AM +0100, Marco Elver wrote: > > > On Sat, 13 Jan 2024 at 02:24, Andi Kleen wrote: > > > > > > > > On Fri, Jan 12, 2024 at 11:15:05PM +0100, Marco Elver wrote: > > > > > + /* > > > > > + * Stack traces of size 0 are never saved, and we can simply use > > > > > + * the size field as an indicator if this is a new unused stack > > > > > + * record in the freelist. > > > > > + */ > > > > > + stack->size = 0; > > > > > > > > I would use WRITE_ONCE here too, at least for TSan. > > > > > > This is written with the pool_lock held. > > > > ...which doesn't help because the readers don't take it? > > This function is only refilling the freelist. Readers don't see it yet > because it's in none of the hash table buckets. The freelist is only > ever accessed under the lock. > > Once an entry is allocated from the freelist, its size is overwritten > with something non-zero (since it then contains a stack trace). Those > updates are released into the right hash table bucket with > list_add_rcu() (which implies a release). > > Am I missing something else? FWIW, the current version (draft) of this can be found here: https://git.kernel.org/pub/scm/linux/kernel/git/melver/linux.git/log/?h=kasan/dev I'll send the 2 patches next week - they should apply cleanly on current mainline. Thanks, -- Marco