diff options
Diffstat (limited to 'debian/patches-rt/0003-zram-Shrink-zram_table_entry-flags.patch')
| -rw-r--r-- | debian/patches-rt/0003-zram-Shrink-zram_table_entry-flags.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/debian/patches-rt/0003-zram-Shrink-zram_table_entry-flags.patch b/debian/patches-rt/0003-zram-Shrink-zram_table_entry-flags.patch new file mode 100644 index 0000000000..153dee8fd2 --- /dev/null +++ b/debian/patches-rt/0003-zram-Shrink-zram_table_entry-flags.patch @@ -0,0 +1,48 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Thu, 20 Jun 2024 12:53:06 +0200 +Subject: [PATCH 3/3] zram: Shrink zram_table_entry::flags. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.10/older/patches-6.10.2-rt14.tar.xz + +The zram_table_entry::flags member is of type long and uses 8 bytes on a +64bit architecture. With a PAGE_SIZE of 256KiB we have PAGE_SHIFT of 18 +which in turn leads to __NR_ZRAM_PAGEFLAGS = 27. This still fits in an +ordinary integer. +By reducing it the size of `flags' to four bytes, the size of the struct +goes back to 16 bytes. The padding between the lock and ac_time (if +enabled) is also gone. + +Make zram_table_entry::flags an unsigned int and update the build test +to reflect the change. + +Link: https://lore.kernel.org/r/20240620153556.777272-4-bigeasy@linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/block/zram/zram_drv.c | 3 ++- + drivers/block/zram/zram_drv.h | 2 +- + 2 files changed, 3 insertions(+), 2 deletions(-) + +--- a/drivers/block/zram/zram_drv.c ++++ b/drivers/block/zram/zram_drv.c +@@ -2412,9 +2412,10 @@ static void destroy_devices(void) + + static int __init zram_init(void) + { ++ struct zram_table_entry zram_te; + int ret; + +- BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > BITS_PER_LONG); ++ BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > sizeof(zram_te.flags) * 8); + + ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare", + zcomp_cpu_up_prepare, zcomp_cpu_dead); +--- a/drivers/block/zram/zram_drv.h ++++ b/drivers/block/zram/zram_drv.h +@@ -66,7 +66,7 @@ struct zram_table_entry { + unsigned long handle; + unsigned long element; + }; +- unsigned long flags; ++ unsigned int flags; + spinlock_t lock; + #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME + ktime_t ac_time; |