From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: John Ogness <john.ogness@linutronix.de>,
Petr Mladek <pmladek@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrea Parri <parri.andrea@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul McKenney <paulmck@kernel.org>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/4] printk: add lockless ringbuffer
Date: Fri, 10 Jul 2020 17:47:44 +0900 [thread overview]
Message-ID: <20200710084744.GA488397@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20200710084305.GA144760@jagdpanzerIV.localdomain>
On (20/07/10 17:43), Sergey Senozhatsky wrote:
> [..]
>
> > +void prb_init(struct printk_ringbuffer *rb,
> > + char *text_buf, unsigned int textbits,
> > + char *dict_buf, unsigned int dictbits,
> > + struct prb_desc *descs, unsigned int descbits)
> > +{
> > + memset(descs, 0, _DESCS_COUNT(descbits) * sizeof(descs[0]));
> > +
> > + rb->desc_ring.count_bits = descbits;
> > + rb->desc_ring.descs = descs;
> > + atomic_long_set(&rb->desc_ring.head_id, DESC0_ID(descbits));
> > + atomic_long_set(&rb->desc_ring.tail_id, DESC0_ID(descbits));
> > +
> > + rb->text_data_ring.size_bits = textbits;
> > + rb->text_data_ring.data = text_buf;
> > + atomic_long_set(&rb->text_data_ring.head_lpos, BLK0_LPOS(textbits));
> > + atomic_long_set(&rb->text_data_ring.tail_lpos, BLK0_LPOS(textbits));
> > +
> > + rb->dict_data_ring.size_bits = dictbits;
> > + rb->dict_data_ring.data = dict_buf;
> > + atomic_long_set(&rb->dict_data_ring.head_lpos, BLK0_LPOS(dictbits));
> > + atomic_long_set(&rb->dict_data_ring.tail_lpos, BLK0_LPOS(dictbits));
> > +
>
> Just a side note: some people want !CONFIG_PRINTK builds. I wonder
> how many people will want !CONFIG_PRINTK_DICT. The core logbuf/dict
> logbuf split is really cool.
We also may be can add a dedicated logbuf for the user-space logs,
as opposed to current "user space can write to the kernel logbuf".
Some folks really dislike that systemd, for instance, can trash
the core kernel logbuf doing a lot of /dev/kmsg writes.
-ss
next prev parent reply other threads:[~2020-07-10 8:47 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 13:23 [PATCH v5 0/4] printk: replace ringbuffer John Ogness
2020-07-09 13:23 ` [PATCH v5 1/4] crash: add VMCOREINFO macro to define offset in a struct declared by typedef John Ogness
2020-07-09 13:23 ` [PATCH v5 2/4] printk: add lockless ringbuffer John Ogness
2020-07-10 8:43 ` Sergey Senozhatsky
2020-07-10 8:47 ` Sergey Senozhatsky [this message]
2020-07-09 13:23 ` [PATCH v5 3/4] Revert "printk: lock/unlock console only for new logbuf entries" John Ogness
2020-07-09 13:23 ` [PATCH v5 4/4] printk: use the lockless ringbuffer John Ogness
2020-07-14 5:26 ` [printk] 96d5c61b1f: stress-ng.timerfd.ops_per_sec 8.3% improvement kernel test robot
2020-07-18 12:10 ` [PATCH v5 4/4] printk: use the lockless ringbuffer Marco Elver
2020-07-19 3:43 ` Sergey Senozhatsky
2020-07-20 6:43 ` Marco Elver
2020-07-20 8:22 ` Andy Shevchenko
2020-07-20 8:34 ` Sergey Senozhatsky
2020-07-20 8:41 ` Sergey Senozhatsky
2020-07-20 9:40 ` Marco Elver
2020-07-20 10:01 ` Dmitry Vyukov
2020-07-20 10:20 ` John Ogness
2020-07-20 10:32 ` Marco Elver
2020-08-11 20:47 ` Nick Desaulniers
2020-08-12 16:40 ` John Ogness
2021-01-22 23:52 ` Issue in dmesg time with lockless ring buffer J. Avila
2021-01-25 13:32 ` John Ogness
2021-01-26 0:00 ` J. Avila
2021-01-29 1:46 ` J. Avila
2020-07-10 8:28 ` [PATCH v5 0/4] printk: replace ringbuffer Petr Mladek
2020-07-13 2:23 ` Sergey Senozhatsky
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