base/memory: pass the base_section in add_memory_block
Subsystems (2)
PATCH 1/1 base/memory: pass the base_section in add_memory_block
The second parameter of init_memory_block() is used to calculate the start_section_nr of this block, which means any section in the same block would get the same start_section_nr.
This patch passes the base_section to init_memory_block(), so that to reduce a local variable and a check in every loop.
--- drivers/base/memory.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
drivers/base/memory.c +3 -4
@@ -664,21 +664,20 @@ static int init_memory_block(struct memory_block **memory,static int add_memory_block (int base_section_nr) {struct memory_block *mem; -int i, ret, section_count =0 , section_nr; +int i, ret, section_count =0 ;for (i = base_section_nr; (i < base_section_nr + sections_per_block) && i <NR_MEM_SECTIONS ; i++) {if (!present_section_nr (i))continue ; -if (section_count ==0 ) - section_nr = i; section_count++; }if (section_count ==0 )return 0 ; - ret =init_memory_block (&mem,__nr_to_section (section_nr),MEM_ONLINE ); + ret =init_memory_block (&mem,__nr_to_section (base_section_nr), +MEM_ONLINE );if (ret)return ret; mem->section_count = section_count;
Signature · 1 line
2.11.0
[Sorry for a late response]
Quoted 3 lines · Wei Yang
The second parameter of
init_memory_block()is used to calculate thestart_section_nrof this block, which means any section in the same block would get the samestart_section_nr.
Could you be more specific what is the problem here?
Quoted 2 lines
This patch passes the
base_sectiontoinit_memory_block(), so that to reduce a local variable and a check in every loop.
But then you are not handling a memblock which starts with a !present section. The code is quite hairy but I do not see why your change is any more correct. This needs much better justification than what the above gives us. Maybe the whole thing about incomplete memblock is just overengineered piece of code, who knows this area is full of stuff that makes only little sense but again the changelog should be pretty verbose about all the consequences and focus on the high level rather than particular issues here and there.
Thanks
Quoted 36 lines
Signed-off-by Wei Yang <[email protected]>--- drivers/base/memory.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)drivers/base/memory.c +3
-4@@ -664,21 +664,20 @@ static int init_memory_block(struct memory_block **memory,static int add_memory_block (int base_section_nr) {struct memory_block *mem; -int i, ret, section_count =0 , section_nr; +int i, ret, section_count =0 ;for (i = base_section_nr; (i < base_section_nr + sections_per_block) && i <NR_MEM_SECTIONS ; i++) {if (!present_section_nr (i))continue ; -if (section_count ==0 ) - section_nr = i; section_count++; }if (section_count ==0 )return 0 ; - ret =init_memory_block (&mem,__nr_to_section (section_nr),MEM_ONLINE ); + ret =init_memory_block (&mem,__nr_to_section (base_section_nr), +MEM_ONLINE );if (ret)return ret; mem->section_count = section_count;Signature · 1 line
2.11.0
Signature · 2 lines
Michal Hocko SUSE Labs
Greg KH
maintainerQuoted 11 lines · Wei Yang
The second parameter of
init_memory_block()is used to calculate thestart_section_nrof this block, which means any section in the same block would get the samestart_section_nr.This patch passes the
base_sectiontoinit_memory_block(), so that to reduce a local variable and a check in every loop.Signed-off-by Wei Yang <[email protected]>--- drivers/base/memory.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
Can you resend this and cc: linux-mm? I think the developers there need to review this.
thanks,
greg k-h