From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: John Ogness Subject: [PATCH next v4 00/15] printk: remove logbuf_lock Date: Wed, 3 Mar 2021 11:15:13 +0100 Message-Id: <20210303101528.29901-1-john.ogness@linutronix.de> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+geert=linux-m68k.org@lists.infradead.org To: Petr Mladek Cc: Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Jeff Dike , Richard Weinberger , Anton Ivanov , Andy Shevchenko , Thomas Meyer , linux-um@lists.infradead.org, Miquel Raynal , Vignesh Raghavendra , linux-mtd@lists.infradead.org, Kees Cook , Pavel Tatashin , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Jason Wessel , Daniel Thompson , Douglas Anderson , Jordan Niethe , Alistair Popple , Ravi Bangoria , Nicholas Piggin , Madhavan Srinivasan , Mike Rapoport , Oleg Nesterov , Wei Li , Davidlohr Bueso , linuxppc-dev@lists.ozlabs.org, kgdb-bugreport@lists.sourceforge.net, "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Anton Vorontsov , Colin Cross , Tony Luck , Christophe Leroy , Michael Kelley , linux-hyperv@vger.kernel.org, Sumit Garg List-ID: Hello, Here is v4 of a series to remove @logbuf_lock, exposing the ringbuffer locklessly to both readers and writers. v3 is here [0]. Since @logbuf_lock was protecting much more than just the ringbuffer, this series clarifies and cleans up the various protections using comments, lockless accessors, atomic types, and a new finer-grained @syslog_lock. Removing @logbuf_lock required changing the semantics of the kmsg_dumper callback in order to work locklessly. This series adjusts all kmsg_dumpers and users of the kmsg_dump_get_*() functions for the new semantics. This series is based on next-20210303. Changes since v3: - disable interrupts in the arch/um kmsg_dumper - reduce CONSOLE_LOG_MAX value from 4096 back to 1024 to revert the increasd 3KiB static memory footprint - change the kmsg_dumper() callback prototype back to how it was because some dumpers need the registered object for container_of() usage - for kmsg_dump_get_line()/kmsg_dump_get_buffer() restrict the minimal allowed sequence number to the cleared sequence number John Ogness [0] https://lore.kernel.org/lkml/20210225202438.28985-1-john.ogness@linutronix.de/ John Ogness (15): um: synchronize kmsg_dumper mtd: mtdoops: synchronize kmsg_dumper printk: limit second loop of syslog_print_all printk: kmsg_dump: remove unused fields printk: refactor kmsg_dump_get_buffer() printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: introduce CONSOLE_LOG_MAX printk: use seqcount_latch for clear_seq printk: use atomic64_t for devkmsg_user.seq printk: add syslog_lock printk: kmsg_dumper: remove @active field printk: introduce a kmsg_dump iterator printk: remove logbuf_lock printk: kmsg_dump: remove _nolock() variants printk: console: remove unnecessary safe buffer usage arch/powerpc/kernel/nvram_64.c | 8 +- arch/powerpc/xmon/xmon.c | 6 +- arch/um/kernel/kmsg_dump.c | 13 +- drivers/hv/vmbus_drv.c | 4 +- drivers/mtd/mtdoops.c | 17 +- fs/pstore/platform.c | 5 +- include/linux/kmsg_dump.h | 47 ++-- kernel/debug/kdb/kdb_main.c | 10 +- kernel/printk/internal.h | 4 +- kernel/printk/printk.c | 464 +++++++++++++++++---------------- kernel/printk/printk_safe.c | 27 +- 11 files changed, 310 insertions(+), 295 deletions(-) -- 2.20.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/