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Re: [PATCH] login: pututline needs to validate the cache under write lock [BZ #24882]
On 21/08/2019 10:20, Florian Weimer wrote:
> * Florian Weimer:
>
>> 2019-08-12 Florian Weimer <fweimer@redhat.com>
>>
>> [BZ #24882]
>> * login/utmp_file.c (file_locking_failed): Report EAGAIN for a
>> failure to acquire the lock.
>> (internal_getut_nolock): New function.
>> Extracted from internal_getut_r.
>> (internal_getut_r): Call it.
>> (__libc_pututline): Acquire write lock before all read operations.
>
> It has been pointed out that this causes too much overhead with high
> load. Scanning entries using the read lock only is apparently important
> for performance.
So do you intend to resend a new version or this extra overhead is required
to fully fix the issue?