On Mon, Nov 21, 2022 at 06:12:02PM +0100, Vlastimil Babka wrote: > As explained in [1], we would like to remove SLOB if possible. > > - There are no known users that need its somewhat lower memory footprint > so much that they cannot handle SLUB (after some modifications by the > previous patches) instead. > > - It is an extra maintenance burden, and a number of features are > incompatible with it. > > - It blocks the API improvement of allowing kfree() on objects allocated > via kmem_cache_alloc(). > > As the first step, rename the CONFIG_SLOB option in the slab allocator > configuration choice to CONFIG_SLOB_DEPRECATED. Add CONFIG_SLOB > depending on CONFIG_SLOB_DEPRECATED as an internal option to avoid code > churn. This will cause existing .config files and defconfigs with > CONFIG_SLOB=y to silently switch to the default (and recommended > replacement) SLUB, while still allowing SLOB to be configured by anyone > that notices and needs it. But those should contact the slab maintainers > and linux-mm@xxxxxxxxx as explained in the updated help. With no valid > objections, the plan is to update the existing defconfigs to SLUB and > remove SLOB in a few cycles. > > To make SLUB more suitable replacement for SLOB, a CONFIG_SLUB_TINY > option was introduced to limit SLUB's memory overhead. > There is a number of defconfigs specifying CONFIG_SLOB=y. As part of > this patch, update them to select CONFIG_SLUB and CONFIG_SLUB_TINY. > > [1] https://lore.kernel.org/all/b35c3f82-f67b-2103-7d82-7a7ba7521439@xxxxxxx/ > > Cc: Russell King <linux@xxxxxxxxxxxxxxx> > Cc: Aaro Koskinen <aaro.koskinen@xxxxxx> > Cc: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx> > Cc: Tony Lindgren <tony@xxxxxxxxxxx> > Cc: Jonas Bonn <jonas@xxxxxxxxxxxx> > Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx> > Cc: Stafford Horne <shorne@xxxxxxxxx> > Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> > Cc: Rich Felker <dalias@xxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > Cc: Conor Dooley <conor@xxxxxxxxxx> > Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> > Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> > Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx> > Cc: <linux-omap@xxxxxxxxxxxxxxx> > Cc: <openrisc@xxxxxxxxxxxxxxxxxxxx> > Cc: <linux-riscv@xxxxxxxxxxxxxxxxxxx> > Cc: <linux-sh@xxxxxxxxxxxxxxx> > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx> Thanks!
