* [PATCH] adjust BAT mapping according to max_low_mem @ 2002-02-08 20:36 Val Henson 2002-02-09 20:47 ` Tom Rini 0 siblings, 1 reply; 3+ messages in thread From: Val Henson @ 2002-02-08 20:36 UTC (permalink / raw) To: linuxppc-dev I'm testing highmem by setting max_low_mem to 64MB and using 256MB RAM total (this does not trigger my SCSI bug). I had to change a few things in adjust_total_lowmem to force it to _not_ BAT map of all the RAM. I think the printout of residual is wrong but I'm not sure. -VAL # This is a BitKeeper generated patch for the following project: # Project Name: Linux 2.4 for PowerPC development tree # This patch format is intended for GNU patch command version 2.5 or higher. # This patch includes the following deltas: # ChangeSet 1.201 -> 1.202 # arch/ppc/mm/pgtable.c 1.15 -> 1.16 # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/02/08 val@evilcat.fsmlabs.com 1.202 # Fix bat calculations to take into account max_low_mem. This maps only the # max_low_mem RAM with BATs, so you can test the highmem code on machines with # less ram. The printout of "residual" is probably wrong, since it now only # lists the residual lowmem, rather than all residual mem. # -------------------------------------------- # diff -Nru a/arch/ppc/mm/pgtable.c b/arch/ppc/mm/pgtable.c --- a/arch/ppc/mm/pgtable.c Fri Feb 8 13:29:29 2002 +++ b/arch/ppc/mm/pgtable.c Fri Feb 8 13:29:29 2002 @@ -205,7 +205,7 @@ #ifdef HAVE_BATS unsigned long bat_max = 0x10000000; unsigned long align; - unsigned long ram = total_lowmem; + unsigned long ram; int is601 = 0; /* 601s have smaller BATs */ @@ -213,6 +213,16 @@ bat_max = 0x00800000; is601 = 1; } + + /* adjust BAT block size to max_low_mem */ + if (max_low_mem < bat_max) + bat_max = max_low_mem; + + /* adjust lowmem size to max_low_mem */ + if (max_low_mem < total_lowmem) + total_lowmem = max_low_mem; + + ram = total_lowmem; /* Make sure we don't map a block larger than the smallest alignment of the physical address. */ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] adjust BAT mapping according to max_low_mem 2002-02-08 20:36 [PATCH] adjust BAT mapping according to max_low_mem Val Henson @ 2002-02-09 20:47 ` Tom Rini 2002-02-09 21:20 ` Tom Rini 0 siblings, 1 reply; 3+ messages in thread From: Tom Rini @ 2002-02-09 20:47 UTC (permalink / raw) To: Val Henson; +Cc: linuxppc-dev On Fri, Feb 08, 2002 at 01:36:04PM -0700, Val Henson wrote: > I'm testing highmem by setting max_low_mem to 64MB and using 256MB RAM > total (this does not trigger my SCSI bug). I had to change a few > things in adjust_total_lowmem to force it to _not_ BAT map of all the > RAM. I think the printout of residual is wrong but I'm not sure. If I'm reading all of the code right, residual at this point should be (total_lowmem (initial value) - ram mapped in BATs), so I think this: > + /* adjust BAT block size to max_low_mem */ > + if (max_low_mem < bat_max) > + bat_max = max_low_mem; > + > + /* adjust lowmem size to max_low_mem */ > + if (max_low_mem < total_lowmem) > + total_lowmem = max_low_mem; > + > + ram = total_lowmem; Should be: /* adjust BAT block size to max_low_mem */ if (max_low_mem < bat_max) bat_max = max_low_mem; /* adjust lowmem size to max_low_mem */ if (max_low_mem < total_lowmem) ram = max_low_mem; else ram = total_lowmem; ... printk(KERN_INFO "Memory BAT mapping: BAT2=%ldMb, BAT3=%ldMb, " "residual: %ldMb\n", __bat2 >> 20, __bat3 >> 20, (total_lowmem - ram) >> 20); Does this sound right? -- Tom Rini (TR1265) http://gate.crashing.org/~trini/ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] adjust BAT mapping according to max_low_mem 2002-02-09 20:47 ` Tom Rini @ 2002-02-09 21:20 ` Tom Rini 0 siblings, 0 replies; 3+ messages in thread From: Tom Rini @ 2002-02-09 21:20 UTC (permalink / raw) To: Val Henson; +Cc: linuxppc-dev On Sat, Feb 09, 2002 at 01:47:16PM -0700, Tom Rini wrote: > > On Fri, Feb 08, 2002 at 01:36:04PM -0700, Val Henson wrote: > > > I'm testing highmem by setting max_low_mem to 64MB and using 256MB RAM > > total (this does not trigger my SCSI bug). I had to change a few > > things in adjust_total_lowmem to force it to _not_ BAT map of all the > > RAM. I think the printout of residual is wrong but I'm not sure. > > If I'm reading all of the code right, residual at this point should be > (total_lowmem (initial value) - ram mapped in BATs), so I think this: > > > + /* adjust BAT block size to max_low_mem */ > > + if (max_low_mem < bat_max) > > + bat_max = max_low_mem; > > + > > + /* adjust lowmem size to max_low_mem */ > > + if (max_low_mem < total_lowmem) > > + total_lowmem = max_low_mem; > > + > > + ram = total_lowmem; > > Should be: > /* adjust BAT block size to max_low_mem */ > if (max_low_mem < bat_max) > bat_max = max_low_mem; > > /* adjust lowmem size to max_low_mem */ > if (max_low_mem < total_lowmem) > ram = max_low_mem; > else > ram = total_lowmem; > ... > > printk(KERN_INFO "Memory BAT mapping: BAT2=%ldMb, BAT3=%ldMb, " > "residual: %ldMb\n", __bat2 >> 20, __bat3 >> 20, > (total_lowmem - ram) >> 20); And after actually testing: printk(KERN_INFO "... (total_lowmem - (__bat2 + __bat3)) >> 20); If someone else can confirm that the above thinking is right, I'll check in the following patch, which fixes this and the printk for more RAM than BATS && !CONFIG_HIGHMEM -- Tom Rini (TR1265) http://gate.crashing.org/~trini/ ===== arch/ppc/mm/pgtable.c 1.15 vs edited ===== --- 1.15/arch/ppc/mm/pgtable.c Mon Jan 28 04:11:59 2002 +++ edited/arch/ppc/mm/pgtable.c Sat Feb 9 14:07:26 2002 @@ -205,7 +205,7 @@ #ifdef HAVE_BATS unsigned long bat_max = 0x10000000; unsigned long align; - unsigned long ram = total_lowmem; + unsigned long ram; int is601 = 0; /* 601s have smaller BATs */ @@ -214,6 +214,16 @@ is601 = 1; } + /* adjust BAT block size to max_low_mem */ + if (max_low_mem < bat_max) + bat_max = max_low_mem; + + /* adjust lowmem size to max_low_mem */ + if (max_low_mem < total_lowmem) + ram = max_low_mem; + else + ram = total_lowmem; + /* Make sure we don't map a block larger than the smallest alignment of the physical address. */ /* alignment of PPC_MEMSTART */ @@ -234,8 +244,9 @@ ram -= __bat3; } - printk(KERN_INFO "Memory BAT mapping: BAT2=%ldMb, BAT3=%ldMb, residual: %ldMb\n", - __bat2 >> 20, __bat3 >> 20, ram >> 20); + printk(KERN_INFO "Memory BAT mapping: BAT2=%ldMb, BAT3=%ldMb," + " residual: %ldMb\n", __bat2 >> 20, __bat3 >> 20, + (total_lowmem - (__bat2 - __bat3)) >> 20); /* On SMP, we limit the lowmem to the area mapped with BATs. * We also assume nobody will do SMP with 601s @@ -249,8 +260,9 @@ if (total_lowmem > max_low_mem) { total_lowmem = max_low_mem; #ifndef CONFIG_HIGHMEM - printk(KERN_INFO "Warning, memory limited to %ld Mb, use CONFIG_HIGHMEM" - " to reach %ld Mb\n", max_low_mem >> 20, total_lowmem >> 20); + printk(KERN_INFO "Warning, memory limited to %ld Mb, use " + " CONFIG_HIGHMEM to reach %ld Mb\n", + max_low_mem >> 20, total_memory >> 20); total_memory = total_lowmem; #endif /* CONFIG_HIGHMEM */ } ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/ ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-02-09 21:20 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2002-02-08 20:36 [PATCH] adjust BAT mapping according to max_low_mem Val Henson 2002-02-09 20:47 ` Tom Rini 2002-02-09 21:20 ` Tom Rini
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