| Message ID | ec03cef8-a883-fd68-a062-c243d782394c@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | assorted replacement of x[mz]alloc_bytes() | expand |
On 08/04/2021 13:17, Jan Beulich wrote: > There is a difference in generated code: xzalloc_bytes() forces > SMP_CACHE_BYTES alignment. I think we not only don't need this here, but > actually don't want it. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> > > --- a/xen/arch/x86/cpu/vpmu_intel.c > +++ b/xen/arch/x86/cpu/vpmu_intel.c > @@ -461,10 +461,10 @@ static int core2_vpmu_alloc_resource(str > goto out_err; > } > > - core2_vpmu_cxt = xzalloc_bytes(sizeof(*core2_vpmu_cxt) + > - sizeof(uint64_t) * fixed_pmc_cnt + > - sizeof(struct xen_pmu_cntr_pair) * > - arch_pmc_cnt); > + core2_vpmu_cxt = xzalloc_flex_struct(struct xen_pmu_intel_ctxt, regs, > + fixed_pmc_cnt + arch_pmc_cnt * > + (sizeof(struct xen_pmu_cntr_pair) / > + sizeof(*core2_vpmu_cxt->regs))); > p = xzalloc(uint64_t); However, this is very wtf, and clearly wants reworking. I'll see if I can find some time, unless anyone else beats me to it. ~Andrew > if ( !core2_vpmu_cxt || !p ) > goto out_err; >
On 08.04.2021 14:25, Andrew Cooper wrote: > On 08/04/2021 13:17, Jan Beulich wrote: >> There is a difference in generated code: xzalloc_bytes() forces >> SMP_CACHE_BYTES alignment. I think we not only don't need this here, but >> actually don't want it. >> >> Signed-off-by: Jan Beulich <jbeulich@suse.com> > > Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> Thanks. >> --- a/xen/arch/x86/cpu/vpmu_intel.c >> +++ b/xen/arch/x86/cpu/vpmu_intel.c >> @@ -461,10 +461,10 @@ static int core2_vpmu_alloc_resource(str >> goto out_err; >> } >> >> - core2_vpmu_cxt = xzalloc_bytes(sizeof(*core2_vpmu_cxt) + >> - sizeof(uint64_t) * fixed_pmc_cnt + >> - sizeof(struct xen_pmu_cntr_pair) * >> - arch_pmc_cnt); >> + core2_vpmu_cxt = xzalloc_flex_struct(struct xen_pmu_intel_ctxt, regs, >> + fixed_pmc_cnt + arch_pmc_cnt * >> + (sizeof(struct xen_pmu_cntr_pair) / >> + sizeof(*core2_vpmu_cxt->regs))); >> p = xzalloc(uint64_t); > > However, this is very wtf, and clearly wants reworking. I'll see if I > can find some time, unless anyone else beats me to it. I thought so too while seeing this, but it's quite a bit more of a rework than I felt I'd like to tackle right away. Jan
--- a/xen/arch/x86/cpu/vpmu_intel.c +++ b/xen/arch/x86/cpu/vpmu_intel.c @@ -461,10 +461,10 @@ static int core2_vpmu_alloc_resource(str goto out_err; } - core2_vpmu_cxt = xzalloc_bytes(sizeof(*core2_vpmu_cxt) + - sizeof(uint64_t) * fixed_pmc_cnt + - sizeof(struct xen_pmu_cntr_pair) * - arch_pmc_cnt); + core2_vpmu_cxt = xzalloc_flex_struct(struct xen_pmu_intel_ctxt, regs, + fixed_pmc_cnt + arch_pmc_cnt * + (sizeof(struct xen_pmu_cntr_pair) / + sizeof(*core2_vpmu_cxt->regs))); p = xzalloc(uint64_t); if ( !core2_vpmu_cxt || !p ) goto out_err;
There is a difference in generated code: xzalloc_bytes() forces SMP_CACHE_BYTES alignment. I think we not only don't need this here, but actually don't want it. Signed-off-by: Jan Beulich <jbeulich@suse.com>