| Message ID | 20200128133343.29905-7-b.zolnierkie@samsung.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | ata: optimize core code size on PATA only setups | expand |
On Tue, Jan 28, 2020 at 02:33:21PM +0100, Bartlomiej Zolnierkiewicz wrote: > Use COMMAND_LINE_SIZE instead PAGE_SIZE for ata_force_param_buf[] > size as libata parameters buffer doesn't need to be bigger than > the command line buffer. > > For many architectures this results in decreased libata-core.o > size (COMMAND_LINE_SIZE varies from 256 to 4096 while the minimum > PAGE_SIZE is 4096). > > Code size savings on m68k arch using atari_defconfig: > > text data bss dec hex filename > before: > 41064 4413 40 45517 b1cd drivers/ata/libata-core.o > after: > 41064 573 40 41677 a2cd drivers/ata/libata-core.o > > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> This looks like a good start, so: Reviewed-by: Christoph Hellwig <hch@lst.de> But evne COMMAND_LINE_SIZE is quite a lot of overhead. Can we maybe add a new Kconfig option to optionally disable the libata.force= entirely?
On 1/29/20 6:18 PM, Christoph Hellwig wrote: > On Tue, Jan 28, 2020 at 02:33:21PM +0100, Bartlomiej Zolnierkiewicz wrote: >> Use COMMAND_LINE_SIZE instead PAGE_SIZE for ata_force_param_buf[] >> size as libata parameters buffer doesn't need to be bigger than >> the command line buffer. >> >> For many architectures this results in decreased libata-core.o >> size (COMMAND_LINE_SIZE varies from 256 to 4096 while the minimum >> PAGE_SIZE is 4096). >> >> Code size savings on m68k arch using atari_defconfig: >> >> text data bss dec hex filename >> before: >> 41064 4413 40 45517 b1cd drivers/ata/libata-core.o >> after: >> 41064 573 40 41677 a2cd drivers/ata/libata-core.o >> >> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> > > This looks like a good start, so: > > Reviewed-by: Christoph Hellwig <hch@lst.de> Thanks. > But evne COMMAND_LINE_SIZE is quite a lot of overhead. Can we maybe add > a new Kconfig option to optionally disable the libata.force= entirely? I've added patch making "libata.force=" optional in v2 (disabling "libata.force=" saves us additional 3kB). Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index fa36e3248039..9b824788d04f 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -52,6 +52,7 @@ #include <linux/leds.h> #include <linux/pm_runtime.h> #include <linux/platform_device.h> +#include <asm/setup.h> #define CREATE_TRACE_POINTS #include <trace/events/libata.h> @@ -106,7 +107,7 @@ struct ata_force_ent { static struct ata_force_ent *ata_force_tbl; static int ata_force_tbl_size; -static char ata_force_param_buf[PAGE_SIZE] __initdata; +static char ata_force_param_buf[COMMAND_LINE_SIZE] __initdata; /* param_buf is thrown away after initialization, disallow read */ module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0); MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/admin-guide/kernel-parameters.rst for details)");
Use COMMAND_LINE_SIZE instead PAGE_SIZE for ata_force_param_buf[] size as libata parameters buffer doesn't need to be bigger than the command line buffer. For many architectures this results in decreased libata-core.o size (COMMAND_LINE_SIZE varies from 256 to 4096 while the minimum PAGE_SIZE is 4096). Code size savings on m68k arch using atari_defconfig: text data bss dec hex filename before: 41064 4413 40 45517 b1cd drivers/ata/libata-core.o after: 41064 573 40 41677 a2cd drivers/ata/libata-core.o Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> --- drivers/ata/libata-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)